The DOI matches its Crossref record; 103 of the 105 references it cites were found in a registry or an index; none of the 17 sources its claims cite is checked for support yet.
Global distributions, source-type dependencies, and concentration ranges of per- and polyfluoroalkyl substances in groundwater
Open accessAbstract
A meta-analysis was conducted of published literature reporting concentrations of per- and polyfluoroalkyl substances (PFAS) in groundwater for sites distributed in 21 countries across the globe. Data for more than 35 PFAS were aggregated from 96 reports published from 1999 to 2021. The final data set comprised approximately 21,000 data points after removal of time-series and duplicate samples as well as non-detects. The reported concentrations ranged over many orders of magnitude, from ng/L to mg/L levels. Distinct differences in concentration ranges were observed between sites located within or near sources versus those that are not. Perfluorooctanoic acid (PFOA), ranging from <0.03 ng/L to ~7 mg/L, and perfluorooctanesulfonic acid (PFOS), ranging from 0.01 ng/L to ~5 mg/L, were the two most reported PFAS. The highest PFAS concentration in groundwater was ~15 mg/L reported for the replacement-PFAS 6:2 fluorotelomer sulfonate (6:2 FTS). Maximum reported groundwater concentrations for PFOA and PFOS were compared to concentrations reported for soils, surface waters, marine waters, and precipitation. Soil concentrations are generally significantly higher than those reported for the other media. This accrues to soil being the primary entry point for PFAS release into the environment for many sites, as well as the generally significantly greater retention capacity of soil compared to the other media. The presence of PFAS has been reported for all media in all regions tested including areas that are far removed from specific PFAS sources. This gives rise to the existence of a “background” concentration of PFAS that must be accounted for in both regional and site-specific risk assessments. The presence of this background is a reflection of the large-scale use of PFAS, their general recalcitrance, and the action of long-range transport processes that distribute PFAS across regional and global scales. This ubiquitous distribution has the potential to significantly impact the quality and availability of water resources in many regions. In addition, the pervasive presence of PFAS in the environment engenders concerns for impacts to ecosystem and human health.
Overview
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Claims the paper makes
70 Own result · 28 No basis given · 20 Own interpretation · 11 Not checked yet
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In the paper
“These concentrations are several orders-of-magnitude lower than those for the primary source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The reported concentrations ranged over many orders of magnitude, from ng/L to mg/L levels.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plain- Asserted: passes — The authors put it forward as true.
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In the paper
“Approximately 40% of the data are reported for sites classified as primary-source sites (Table 2).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
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In the paper
“The highest concentrations reported for the no-known-source sites are generally associated with metropolitan areas.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plaincorrelational- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The highest PFAS concentration in groundwater was ~15 mg/L reported for the replacement-PFAS 6:2 fluorotelomer sulfonate (6:2 FTS).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plain- Asserted: passes — The authors put it forward as true.
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In the paper
“The median of the maximum concentrations reported for secondary-source sites are 95 and 96 ng/L for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plain- Asserted: passes — The authors put it forward as true.
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In the paper
“The maximum PFOA concentrations range from approximately 8.8 ng/L to ~0.6 mg/L, with a median of 569 ng/L.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plain- Asserted: passes — The authors put it forward as true.
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In the paper
“The concentrations are observed to exhibit a skewed distribution for the source sites, with one or two sites comprising the highest reported concentrations.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plain- Asserted: passes — The authors put it forward as true.
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In the paper
“Data reported for no-known-source sites comprise approximately 29% of the total.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
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In the paper
“The weighted mean concentrations of PFOA and PFOS at primary source sites are 64,000 (±29000) ng/L and 93,000 (±27000) ng/L, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
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In the paper
“Notably, the median of the maximum PFOS concentrations for the source sites is only a factor of two larger than the median of the maximum concentration for the no-known-source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plain- Asserted: passes — The authors put it forward as true.
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The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The highest reported concentrations are associated with aqueous film-forming foams (AFFF) application sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plaincorrelational- Asserted: passes — The authors put it forward as true.
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None of the sources cited for this claim have been checked yet.
In the paper
“The characterized plume lengths range from approximately 0.5 to >5 km.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“and 42 (±24) ng/L and 46 (±48) ng/L, respectively, for PFOS.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“perfluorooctanesulfonic acid (PFOS), ranging from 0.01 ng/L to ~5 mg/L”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plain- Asserted: passes — The authors put it forward as true.
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The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Soil concentrations are generally significantly higher than those reported for the other media.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The presence of PFAS has been reported for all media in all regions tested including areas that are far removed from specific PFAS sources.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The arithmetic mean concentrations for all sites for PFOA and PFOS, the two most reported PFAS in groundwater, are 15,000 (±12000) ng/L and 21,000 (±11000) ng/L, respectively (Table 3).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The maximum concentrations range up to 9.7 (9.7×106 ng/L) and 6.6 mg/L (6.6×106 ng/L) for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Distinct differences in concentration ranges were observed between sites located within or near sources versus those that are not.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Perfluorooctanoic acid (PFOA), ranging from <0.03 ng/L to ~7 mg/L”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The final data set comprised approximately 21,000 data points after removal of time-series and duplicate samples as well as non-detects.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The weighted mean concentrations of PFOA and PFOS at primary source sites are 64,000 (±29000) ng/L and 93,000 (±27000) ng/L, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
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- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“and 42 (±24) ng/L and 46 (±48) ng/L, respectively, for PFOS.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The maximum PFOS concentrations range from 2.5 ng/L to 0.3 mg/L, with a median of 22 ng/L.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The maximum PFOS concentrations range from approximately 0.3 ng/L to ~350 ng/L, with a median of 10 ng/L.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The concentrations reported for these latter two source types are several orders of magnitude lower than those reported for primary-source sites. This disparity is observed for all reported PFAS with the exception of the longer-chain C11 – C18 PFAS.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plaincorrelational- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values of the maximum groundwater concentrations reported for the no-known-source sites are approximately 30 and 15 ng/L for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The maximum concentrations range up to 9.7 (9.7×106 ng/L) and 6.6 mg/L (6.6×106 ng/L) for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values of the maximum groundwater concentrations reported for primary-source sites are approximately 45,700 and 7,400 ng/L for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median of the maximum concentrations reported for secondary-source sites are 95 and 96 ng/L for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The weighted means for secondary-source sites and no-known source sites are 325 (±320) ng/L and 13 (±5) ng/L, respectively, for PFOA”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“In contrast to the source sites, the median values are in a similar range for PFOS and PFOA for the no-known-source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“PFAS production and manufacturing facilities comprise nearly one-third of the primary-source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The maximum PFOA concentrations range from 0.4 ng/L to ~1,000 ng/L, with a median of 17 ng/L.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values of the maximum groundwater concentrations reported for the no-known-source sites are approximately 30 and 15 ng/L for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Conversely, the concentrations for the no-known-source sites exhibit a normal distribution.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plain- Asserted: passes — The authors put it forward as true.
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- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Data for more than 35 PFAS were aggregated from 96 reports published from 1999 to 2021.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
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A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The weighted means for secondary-source sites and no-known source sites are 325 (±320) ng/L and 13 (±5) ng/L, respectively, for PFOA”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median concentrations for the secondary-source sites are 2–3 orders-of-magnitude lower than those for the primary-source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plaincorrelational- Asserted: passes — The authors put it forward as true.
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- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The median PFOA concentration is more than 20-times larger than that of PFOS.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values of the maximum groundwater concentrations reported for primary-source sites are approximately 45,700 and 7,400 ng/L for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Approximately 30% of the data are reported for secondary-source sites”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The arithmetic mean concentrations for all sites for PFOA and PFOS, the two most reported PFAS in groundwater, are 15,000 (±12000) ng/L and 21,000 (±11000) ng/L, respectively (Table 3).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Overall, the concentrations of PFOS and PFOA reported for the marine waters are generally much lower than those reported for the other media.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median PFOS maximum concentrations for the source sites are observed to be two and three orders-of-magnitude larger than the median no-known-source concentration.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Based on the results of this study, PFOS, PFOA, and other PFAS are obviously present in soil and waters at concentrations ranging across many orders of magnitude, from part-per-trillion to ppm levels.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
boosted- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Inspection of Tables 2 and SI1–2 reveals that the reported concentrations at many of the sites are greater than regulatory or advisory levels that have been implemented for PFAS in drinking water.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“However, a range of additional PFAS have been reported, the specific numbers of which vary greatly among the studies.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values of the maximum soil concentrations for primary-source sites are 4,000 and 58 μg/kg for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The mean values of the reported concentrations are greater than this value for the great majority of the tabulated PFAS (Table 2).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plainn = 16- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The higher concentrations are generally associated with restricted and semi-closed seas, coastal shorelines, and bays adjacent to high vessel-traffic ports and high population/industrialized centers.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Marine Waters
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Similar to the source sites, the soil concentrations for the no-known-source sites are orders-of-magnitude higher than for the other media.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The addition of the new studies did not significantly change the outcomes of the original study.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Distinct differences in concentration ranges were observed between sites located within or near sources versus those that are not.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The maximum PFOA concentrations for rainwater range from 0.07 to 121 ng/L, with a median of 10 ng/L.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Precipitation
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These concentrations are below the EPA’s lifetime health advisory (LHA) of 70 ng/L”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Rests on an assumption: The U.S. EPA set a 70 ng/L lifetime health advisory for PFOS and PFOA in drinking water.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The medians of the maximum soil concentrations for no-known-source sites are 2.7 and 3.1 μg/kg for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“In addition, PFOS and PFOA exhibit opposing skewed distributions.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Comparison of the values shows that soil concentrations are typically orders-of-magnitude higher than those reported for the other media.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Conversely, the PFOA median concentration is 30 times larger for the source sites compared to the no-known-source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The medians of the maximum soil concentrations for no-known-source sites are 2.7 and 3.1 μg/kg for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“A large fraction of the groundwater studies were concentrated in a few regions.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“ppm-level concentrations have been reported for some sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values of the maximum soil concentrations for primary-source sites are 4,000 and 58 μg/kg for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“However, a range of additional PFAS have been reported, the specific numbers of which vary greatly among the studies.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The medians for secondary source sites are 350 and 38 μg/kg for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Conversely, they are approximately one order-of-magnitude larger for PFOA.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“PFAS was determined to be present in groundwater across the globe.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“but are above limits enacted in some U.S. states.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“while the mean concentrations reported for PFOS in soil and groundwater are in the part-per-billion range”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The medians for secondary source sites are 350 and 38 μg/kg for PFOS and PFOA, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Notably, the median values of the maximum PFOA concentrations in precipitation, surface water, and groundwater are very similar for the no-known-source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“PFOS and PFOA have been the primary focus of many prior studies and are typically present in the highest or near-highest concentrations.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Concentrations in soil are typically much greater than those in all other media.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This may result from the preponderance of industrial/manufacturing facilities in the regions with the highest PFAS concentrations, and the specific profile of PFAS associated with these facilities.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“as well as the generally significantly greater retention capacity of soil compared to the other media.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This gives rise to the existence of a “background” concentration of PFAS that must be accounted for in both regional and site-specific risk assessments.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“While there have been many recent reviews providing anecdotal overviews of PFAS occurrence in various media, a detailed, quantitative analysis of PFAS concentrations and distributions specifically for groundwater at a global scale has yet to be reported.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Introduction
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“It has become evident that PFAS are ubiquitous in environmental media across the globe (e.g., Prevedouros et al. 2006; Rayne and Forest, 2009; Ahrens, 2011; Krafft and Riess, 2015; Brusseau et al. 2020).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Introduction
What the sources say
boosted- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These relatively large plume lengths are consistent with the relatively low magnitudes of sorption and transformation anticipated for many PFAS in groundwater systems.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The presence of this background is a reflection of the large-scale use of PFAS, their general recalcitrance, and the action of long-range transport processes that distribute PFAS across regional and global scales.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This accrues to soil being the primary entry point for PFAS release into the environment for many sites”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“The observation of PFAS concentrations in soil often being orders of magnitude greater than those in groundwater has been reported in prior studies (Anderson et al. 2019; Brusseau et al., 2020).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
What the sources say
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“Porewater concentrations are anticipated to range from ng/L to mg/L depending upon soil concentrations, which in turn depend upon the nature of the sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
What the sources say
- Not checked yetcites Brusseau and Guo, 2022 source
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“The results of initial field and mathematical-modeling studies reflect these anticipated concentrations (Guo et al., 2020; Quinnan et al., 2021; Brusseau and Guo, 2022).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
What the sources say
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This gives rise to the existence of a “background” concentration of PFAS.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This disparity is likely related to differences in source concentrations and in the impacts related to dilution and dispersal processes.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The lower concentrations of PFAS present in open-sea regions were attributed primarily to atmospheric deposition, shipping routes, or general transport and dilution processes from distant sources.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Marine Waters
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This indicates that PFAS are pervasive and widely distributed throughout the environment globally.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“These results demonstrate that PFAS are present in precipitation at significant levels.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Precipitation
boosted- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
None of the sources cited for this claim have been checked yet.
In the paper
“The presence of PFAS in drinking water has been illustrated in multiple studies (e.g., Hu et al., 2016; Guelfo and Adamson, 2018).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
What the sources say
- Not checked yetcites Hu et al., 2016
- Not checked yetcites Guelfo and Adamson, 2018 source
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“A critical implication of this is the potential for PFAS to be present in potable water supplies originating from impacted sources.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
In the paper
“the European Commission has proposed a limit of 100 ng/L for each of 16 individual PFAS in the 2018 revision of the EU Drinking Water Directive (EEA, 2022).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
What the sources say
- Not checked yetcites EEA, 2022
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Conversely, the higher PFAS concentrations reported for coastal waters were generally attributed to surface runoff and river discharges.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Marine Waters
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- It may state two separate claims as one. 26
- Probably not a substantial claim. 9
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“More than half of these sites are identified as military installations or airports, primarily comprising AFFF-impacted sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Groundwater Results and Discussion > PFAS Concentrations in Groundwater
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The aggregated surface-water studies used for the comparison of maximum PFOA and PFOS concentrations comprise a total of more than 1,700 sampling sites, with concentration data collected from >30 countries and regions.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Surface Water
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“Conversely, they are 3 and 6 times lower, respectively, than those reported for the secondary source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The maximum concentrations of PFOS and PFOA in snow range from ~0.5–545 and ~20–66 ng/L, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Precipitation
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“For example, the median values of the maximum groundwater concentrations are 30 and 15 ng/L for PFOS and PFOA, respectively, for no-known-source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values of the maximum concentrations are 0.2 and 0.3 ng/L, respectively, for PFOS and PFOA in the marine waters.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values of the maximum PFOS and PFOA soil concentrations are 4,000,000 and 58,000 ng/kg, respectively, for the primary-source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values for PFOS and PFOA, respectively, are approximately 45,700 and 7,400 ng/L for groundwater and 22 and 570 ng/L for surface water.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values of the maximum PFOS and PFOA soil concentrations for no-known-source sites are 2,700 and 3,100 ng/kg, respectively.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median of the maximum PFOS concentrations in rainwater is ~3 ng/L, with the maximums ranging from 0.1 to 50 ng/L.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Precipitation
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The reported concentrations of PFAS in groundwater ranged over many orders of magnitude, with the highest concentrations in part-per-million (ppm) levels.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The results presented in this study demonstrate the widespread presence of PFAS in both groundwater and surface water.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
boosted- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The no-known-source-site median values for PFOS and PFOA, respectively, are 30 and 15 ng/L for groundwater and 10 and 18 ng/L for surface water.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The median values are ~3 and ~18 ng/L, respectively, for PFOS and PFOA in precipitation (combined rainwater and snow data).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The presence of PFAS has been reported for all environmental media in all regions tested including areas that are far removed from specific PFAS sources.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median of the maximum PFOS concentrations is 0.2 ng/L, with the maximums ranging from 0.001 to ~760 ng/L.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Marine Waters
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The median values for PFOS and PFOA, respectively, are approximately 45,700 and 7,400 ng/L for groundwater and 22 and 570 ng/L for surface water.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Twenty studies were accessed that reported concentrations of PFAS in precipitation.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Precipitation
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“As noted above, the concentrations reported for PFOS and PFOA in precipitation are in the ng/L range.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: fails — The paper may give no reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The maximum PFOA concentrations range from 0.001 to ~1,600 ng/L, with a median of 0.3 ng/L.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Marine Waters
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“The PFOS and PFOA groundwater concentrations are three and one orders-of-magnitude higher, respectively, than those for surface water for the source sites.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plaincorrelational- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A result the paper reports from its own data — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The distributions are approximately positively skewed, with the greatest number of concentrations within a range of 0.01–0.3 ng/L.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Marine Waters
plain- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
In the paper
“Furthermore, groundwater is estimated to represent 26% of total water withdrawals for combined domestic, industrial, and irrigation uses (Margat and van der Gun, 2013).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Introduction
What the sources say
- Not checked yetcites Margat and van der Gun, 2013
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
None of the sources cited for this claim have been checked yet.
In the paper
“Many of these compounds, of which several thousand have been identified (OECD, 2018), are known to be environmentally persistent, bioaccumulative (especially long-chain homologues), and have potential deleterious toxicological impacts to a variety of organisms (e.g., Buck et al. 2011).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Introduction
What the sources say
- Not checked yetcites OECD, 2018
- Not checked yetcites Buck et al. 2011 source
boosted- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. It may state two separate claims as one.
In the paper
“For example, groundwater is estimated to provide almost half of all drinking water worldwide (UNESCO, 2022).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Introduction
What the sources say
- Not checked yetcites UNESCO, 2022
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Hence, it is possible that some of the sites may have been impacted by sources either identified but located relatively far away or unidentified.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
In the paper
“The disparity between the two distributions reflects in part the nature of the sources, with AFFF-impacted sources comprising the great majority of primary source sites (Brusseau et al., 2020).”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Soil
What the sources say
- Not checked yetcites Brusseau et al., 2020 source
plainconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“This result may in part reflect large-scale transport of PFOA throughout the hydrologic cycle.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“It is probable that PFAS present in marine systems experience greater magnitudes of dilution and dispersal compared to the other systems. In addition, the concentrations of PFAS entering marine systems are anticipated to be generally lower than inputs to other media.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
hedgedconditional- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The delineation of no-known-source sites in particular may in some cases be nebulous”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
- Rests on an assumption: Many PFAS sources remain undiscovered.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The significantly higher concentrations observed for PFOS compared to PFOA for soil and groundwater is related to many of the primary-source sites comprising AFFF-impacted sites and that PFOS was a primary PFAS in AFFF.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The presence of this background is a reflection of the large-scale use of PFAS, their general recalcitrance, and the action of long-range transport processes that distribute PFAS across regional and global scales.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The paper states this without a source or data behind it here, so there is nothing to check it against. The quote shows it is in the paper.
In the paper
“For example, one source of PFAS release into marine waters is precipitation.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Comparison of Concentrations
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: fails — The paper’s conclusions may not depend on it.
- Based: passes — The paper gives a reason why it holds.
Probably not a substantial claim. The paper’s conclusions may not depend on it.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The ubiquitous distribution of PFAS in the global hydrosphere poses a threat to drinking-water quality and water-resource sustainability.”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Conclusion
plaindirect- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
It may state two separate claims as one.
The authors state this as an assumption.
The reported PFAS concentrations represent total concentrations of individual PFAS.
“Thus, the reported concentrations are assumed to represent total concentration of the individual PFAS.”
The paper relies on this without support.
The source-type classifications provided by the original studies are accurate.
“The classification of the sites was based on information reported by the authors of the original studies.”
The paper relies on this without support.
Variations in sample processing, analysis methods, and detection limits across studies do not invalidate the aggregated comparisons.
“Sample processing and analysis methods varied somewhat across the studies, and the reported quantitative detection limits (LOQ) also varied among the studies.”
The paper relies on this without support.
Excluding non-detects does not bias the concentration distributions.
“Non-detects were not included in the analyses.”
The paper relies on this without support.
Many PFAS sources remain undiscovered.
“considering that it is quite likely that there are many PFAS sources yet to be discovered.”
The paper relies on this without support.
The U.S. EPA set a 70 ng/L lifetime health advisory for PFOS and PFOA in drinking water.
“These concentrations are below the EPA’s lifetime health advisory (LHA) of 70 ng/L”
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The cited source says what the claim attributes to it.
In the citing paper
“Due to the extensive use and consequent discharge, PFAS have been identified in a range of environmental contexts, such as drinking water (7, 8), surface and groundwater (9, 10), soils (11, 12), wastewater (13, 14), landfills (15), remote areas (far from any local point sources, e.g., Arctic environment) (16, 17), and agricultural plants (18).”
From Toward the development of a molecular toolkit for the microbial remediation of per-and polyfluoroalkyl substances (2024) · cites this paper as [9]
In the citing paper
“For example, Johnson et al.28 reviewed 96 studies for PFAS distribution in groundwater of which AFFF-impacted sites made up 32% of known sources, 18% in locations impacted by PFAS manufacturing and industrial activities, and only 3% for biosolid application sites.”
From Sources and Pathways of PFAS Occurrence in Water Sources: Relative Contribution of Land-Applied Biosolids in an Agricultural Dominated Watershed (2025) · cites this paper as [28]
In the citing paper
“Moreover, in the biosolid sites, only one study evaluated PFAS mobilization to drinking wells beyond the biosolid application site.”
From Sources and Pathways of PFAS Occurrence in Water Sources: Relative Contribution of Land-Applied Biosolids in an Agricultural Dominated Watershed (2025) · cites this paper as [28]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
Each contradiction between two passages listed here was confirmed by an independent check.
Rated major: it would touch a result — a value a result rests on, reported and recomputed p-values on opposite sides of the significance level, two passages that conflict with no sign which is right, or a cited work retracted before this paper was published.
In the paper
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Abstract
“perfluorooctanesulfonic acid (PFOS), ranging from 0.01 ng/L to ~5 mg/L”
§ Global Distributions, Source-Type Dependencies, and Concentration Ranges of Per- and Polyfluoroalkyl Substances in Groundwater > Comparison of PFAS Concentrations in Groundwater to Other Media > Groundwater
“The maximum concentrations range up to 9.7 (9.7×106 ng/L) and 6.6 mg/L (6.6×106 ng/L) for PFOS and PFOA, respectively.”
Citations
Cites
Buck, R. C., Franklin, J., Berger, U., Conder, J. M., Cousins, I. T., de Voogt, P., Jensen, A. A., Kannan, K., Mabury, S. A., & van Leeuwen, S. P. (2011) · Integrated Environmental Assessment and Management · doi:10.1002/ieam.258 · Cited by 4,641
Sources, fate and transport of perfluorocarboxylates
Prevedouros, K., Cousins, I. T., Buck, R. C., & Korzeniowski, S. H. (2006) · Environmental Science & Technology · doi:10.1021/es0512475 · Cited by 2,594
Hu, X. C., Andrews, D. Q., Lindstrom, A. B., Bruton, T. A., Schaider, L. A., Grandjean, P., Lohmann, R., Carignan, C. C., Blum, A., Balan, S. A., et al. (2016) · Environmental Science & Technology Letters · doi:10.1021/acs.estlett.6b00260 · Cited by 1,333
Loos, R., Giovanni, L., Comero, S., Serafino, C., Schwesig, D., Werres, F., Balsaa, P., Gans, O., Weiss, S., Bláha, L., et al. (2010) · Water Research · doi:10.1016/j.watres.2010.05.032 · Cited by 891
Persistence of Perfluoroalkyl Acid Precursors in AFFF-Impacted Groundwater and Soil
Houtz, E. F., Higgins, C. P., Field, J. A., & Sedlak, D. L. (2013) · Environmental Science & Technology · doi:10.1021/es4018877 · Cited by 849
PFAS concentrations in soils: Background levels versus contaminated sites
Brusseau, M. L., Anderson, R. H., & Guo, B. (2020) · Science of The Total Environment · doi:10.1016/j.scitotenv.2020.140017 · Cited by 817
Self-citationPolyfluoroalkyl compounds in the aquatic environment: a review of their occurrence and fate
Ahrens, L. (2011) · J. Environ. Monit. · doi:10.1039/c0em00373e · Cited by 759
Backe, W. J., Day, T. C., & Field, J. A. (2013) · Environmental Science & Technology · doi:10.1021/es3034999 · Cited by 611
Rayne, S., & Forest, K. (2009) · Journal of Environmental Science and Health, Part A · doi:10.1080/10934520903139811 · Cited by 475
Anderson, R. H., Long, G. C., Porter, R. C., & Anderson, J. K. (2016) · Chemosphere · doi:10.1016/j.chemosphere.2016.01.014 · Cited by 394
Cited by
Sorted by citations
Brunn, H., Arnold, G., Körner, W., Rippen, G., Steinhäuser, K. G., & Valentin, I. (2023) · Environmental Sciences Europe · doi:10.1186/s12302-023-00721-8 · Cited by 504
Groundwater-Surface water interactions research: Past trends and future directions
Irvine, D. J., Singha, K., Kurylyk, B. L., Briggs, M. A., Sebastian, Y., Tait, D. R., & Helton, A. M. (2024) · Journal of Hydrology · doi:10.1016/j.jhydrol.2024.132061 · Cited by 139
Campos-Pereira, H., Kleja, D. B., Ahrens, L., Enell, A., Kikuchi, J., Pettersson, M., & Gustafsson, J. P. (2023) · Chemosphere · doi:10.1016/j.chemosphere.2023.138133 · Cited by 123
“The selected compounds represent PFASs of environmental concern frequently found in soils (Brusseau et al., 2020), as well as in groundwaters (Johnson et al., 2022) and in bulk deposition (Cousins et al., 2022).”
BackgroundSong, D., Qiao, B., Yao, Y., Zhao, L., Wang, X., Chen, H., Zhu, L., & Sun, H. (2023) · Journal of Hazardous Materials · doi:10.1016/j.jhazmat.2023.132411 · Cited by 98
Neurotoxicity of per- and polyfluoroalkyl substances: Evidence and future directions
Bharal, B., Ruchitha, C., Kumar, P., Pandey, R., Rachamalla, M., Niyogi, S., Naidu, R., & Kaundal, R. K. (2024) · The Science of The Total Environment · doi:10.1016/j.scitotenv.2024.176941 · Cited by 94
Metadata
- Authors
- Johnson, G. R., Brusseau, M. L., Carroll, K. C., Tick, G. R., & Duncan, C. M.
- Affiliations
- Portland State University (US)
- University of Arizona (US)
- New Mexico State University (US)
- University of Alabama (US)
- University of Maryland, College Park (US)
- Corresponding author
- Johnson, Gwynn R.
- Brusseau, Mark L.
- Venue
- Science of The Total Environment
- Publisher
- Elsevier BV
- Published
- 2022-10
- Volume
- 841
- Pages
- 156602
- ISSN
- 0048-9697 (ISSN-L)
- PMC
- PMC9653090
- OpenAlex
- W4281734724
- Semantic Scholar
- 297055efd066dd6b35a92142827bc86671991c5e
- Cited by
- 173
- References
- 105
- Citations by year
- 2026: 51 · 2025: 63 · 2024: 32 · 2023: 24 · 2022: 3
- FWCI
- 10.81
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Licence
- www.elsevier.com/tdm/userlicense/1.0/ (tdm)
- www.elsevier.com/legal/tdmrep-license (tdm)
- www.elsevier.com/open-access/userlicense/1.0/ (am, 251 d)
- doi.org/10.15223/policy-017 (stm-asf)
- doi.org/10.15223/policy-037 (stm-asf)
- doi.org/10.15223/policy-012 (stm-asf)
- doi.org/10.15223/policy-029 (stm-asf)
- doi.org/10.15223/policy-004 (stm-asf)
- Locations
- The Science of The Total Environment (acceptedVersion)
- PubMed (publishedVersion)
- PubMed Central (acceptedVersion)
- PDXScholar (Portland State University) (submittedVersion)
- Funders
- National Institute of Environmental Health Sciences (P42 ES04940)
- National Institute of Food and Agriculture (1023257)
- Topics
- Physical Sciences › Environmental Science › Environmental Chemistry › Per- and polyfluoroalkyl substances research
- Physical Sciences › Environmental Science › Water Science and Technology › Fluoride Effects and Removal
- Physical Sciences › Environmental Science › Health, Toxicology and Mutagenesis › Chemical Analysis and Environmental Impact
- Keywords
- per- and polyfluoroalkyl substances, PFAS, groundwater contamination, global distribution, perfluorooctanoic acid, PFOS, fluorotelomer sulfonates, background concentrations, long-range transport, soil contamination, water quality, risk assessment
- MeSH terms
- Fluorocarbons, Humans, Soil, Water Pollutants, Chemical, Alkanesulfonic Acids, Ecosystem, Groundwater
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-10-07, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
A second model labelled each claim on 2026-10-07 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
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