Microplastic Contamination of Seafood Intended for Human Consumption: A Systematic Review and Meta-Analysis

“The Cochran ’ s Q statistic refers to the null hypothesis of homogeneity and is expressed in the chi-square and p -values (Higgins et al. 2003).”

“The DerSimonian-Laird t 2 estimator was used for all the random-e ff ects models (DerSimonian and Laird 1986, 2015) because this accounts for variations both within and between studies.”

“The Higgins I 2 test and the chi-squared Cochran ’ s Q statistic were used to assess statistical heterogeneity (Higgins and Thompson 2002; Higgins et al. 2003).”

“The MP contents for species of the same family in the same study were pooled using the formulae for combining groups proposed by Higgins and Green (2011, Table 7.7a) (Table S3).”

“…and models executing all analysis via RStudio (version 1.2.1335; RStudio), using the additional packages meta (version 4.9-7; Schwarzer 2019), metaphor (version 2.1-0; Viechtbauer 2010), dmetar (Harrer et al. 2019a), robvis (McGuinness and Kothe 2019), and ggplot2 (Wickham et al. 2016).”

“Furthermore, heterogeneity can inform whether it is appropriate to combine data from di ff erent studies (Borenstein et al. 2009).”

“However, a recent report by the Ocean Conservancy and McKinsey Center for Business and Environment (2015) argued that more than 50% of the plastic pollution of the oceans, originating from land, comes from fi ve Asian countries (Jambeck et al. 2015).”

“The calculator draws on the methods developed by Luo et al. (2018) for the estimation of the mean of the sample and the methods by Wan et al. (2014) for the estimation of the SD.”

“The calculator draws on the methods developed by Luo et al. (2018) for the estimation of the mean of the sample and the methods by Wan et al. (2014) for the estimation of the SD.”

“The MP health e ff ects that are currently under consideration include all three categories (Smith et al. 2018; Wright and Kelly 2017).”

“In contrast, other research and reviews report higher MP and plastic concentrations in the convergence zones of the subtropical gyres and higher concentrations in the open ocean than in coastal areas (Avio et al. 2017; Barrows et al. 2018; Cózar et al. 2014; Eriksen et al. 2014).”

“A recent review by Cox et al. (2019) reported MP content of 1 : 48 MPs = g for seafood, which is consistent with the higher end of the results reported here.”

“The DerSimonian-Laird t 2 estimator was used for all the random-e ff ects models (DerSimonian and Laird 1986, 2015) because this accounts for variations both within and between studies.”

“Recent reviews by Hermsen et al. (2018) and Koelmans et al. (2019) proposed quality assessment systems for MPs research regarding biota samples and water samples, respectively, similar to the RoB tool used in the present meta-analysis.”

“Microplastics (MPs) are broadly de fi ned as synthetic polymeric particles <5 mm in diameter (Frias and Nash 2019; GESAMP 2015, 2016), often also including nanoplastics, which are <100 nm in diameter (Lusher et al. 2017a).”

“The generation of plastic waste and mismanagement of its disposal is expected to triple by 2060, reaching 155–265million metric tons per year (Lebreton and Andrady 2019).”

“The study by Van Cauwenberghe and Janssen (2014) sampled only farmed organisms.”

“The presence of MPs has been con-fi rmed in both human lung tissue (Pauly et al. 1998) and the GI tract (Schwabl et al. 2019).”

“There is a growing body of evidence regarding e ff ects in aquatic animals, but health e ff ects on humans are still unclear (Karbalaei et al. 2018; Sharma and Chatterjee 2017; Smith et al. 2018).”

“MPs are ubiquitous in the environment, with marine environments especially a ff ected owing to the amount of plastic waste they receive (Burns and Boxall 2018; Gourmelon 2015; J Li et al. 2016).”

“…and models executing all analysis via RStudio (version 1.2.1335; RStudio), using the additional packages meta (version 4.9-7; Schwarzer 2019), metaphor (version 2.1-0; Viechtbauer 2010), dmetar (Harrer et al. 2019a), robvis (McGuinness and Kothe 2019), and ggplot2 (Wickham et al. 2016).”

“Recent studies have started to quantify indoor and out-door air MP levels, for example, Dris et al. (2017) reported concentrations of 1 : 0 – 60 MPs = m 3 (indoor) and 0 : 3 – 1 : 5 MPs = m 3 (outdoor) in air, whereas Liu et al. (2019) measured levels of 0 – 4 : 18 MPs = m 3 in outdoor air.”

“…food intended for human consumption, with this emerging risk and the possible e ff ects on health, has raised concern in the scienti fi c community (Barboza et al. 2018; Diepens and Koelmans 2018; Santillo et al. 2017; Waring et al. 2018) as well as among stakeholders (GESAMP 2015, 2016) and…”

“The key identi fi ed exposure route is ingestion (along with inhalation) (Chang et al. 2020; Hale et al. 2020), with seafood being a major medium of exposure (van Raamsdonk et al. 2020; YL Wang et al. 2020).”

“They can be classified into two categories according to their origin: primary (intermediate feedstock, pellets/resin, by-products), and secondary (formed through fragmentation and degradation) (Carbery et al. 2018;Karlsson et al. 2018).”

“…models were preferred over fi xed-e ff ects models because it was assumed that the samples did not share one common true e ff ect size that was in fl u-enced equally by the same factors but, rather, a distribution of true e ff ect sizes (Chen and Peace 2013; Harrer et al. 2019b; Veroniki et al. 2016).”

“In contrast, other research and reviews report higher MP and plastic concentrations in the convergence zones of the subtropical gyres and higher concentrations in the open ocean than in coastal areas (Avio et al. 2017; Barrows et al. 2018; Cózar et al. 2014; Eriksen et al. 2014).”

“…atmospheric MP contamination presents an additional pathway for MP human exposures (Chen et al. 2020), related to direct exposures via inhalation (Wright et al. 2020) and indirect exposures via nondietary ingestion routes of hand-to-mouth behavior (Gasperi et al. 2018), inadvertent ingestion…”

“There is a growing body of evidence regarding e ff ects in aquatic animals, but health e ff ects on humans are still unclear (Karbalaei et al. 2018; Sharma and Chatterjee 2017; Smith et al. 2018).”

“Four studies were excluded: Leslie et al. (2017) used a di ff erent approach for the analysis and reported their results as MP per gram of dry weight, two studies reported results per individual organism (Birnstiel et al. 2019; Digka et al. 2018), and one reported frequency of MP occurrence (Bour et…”

“It has been argued in recent reviews (Miller et al. 2017; Lusher et al. 2017b; Silva et al. 2018) and method papers (Claessens et al. 2013; Collard et al. 2015; Dehaut et al. 2016) that the use of di ff erent chemical and physical treatments for the extraction of particles can in fl uence the e ff…”

“A recent review has attempted to extrapolate to human exposures, reporting annual inhalation of 1 : 9 × 10 3 – 1 : 0 × 10 5 MPs (indoors) and 0 – 3 : 0 × 10 7 MPs (outdoors) (Zhang et al. 2020).”

“Although J Li et al. (2015, 2018) were identi fi ed as statistical out-liers and the major in fl uencers of the e ff ect size, they were not omitted from the analysis because they were rated as having low RoB.”

“…persistent particles; over time they have contaminated all compartments of marine ecosystems, including the food web and biota across di ff erent trophic levels, such as bivalves (SY Zhao et al. 2018), crustaceans (F Zhang et al. 2019), fi sh, and mammals (Lusher et al. 2015; Nelms et al. 2018).”

“…argued in recent reviews (Miller et al. 2017; Lusher et al. 2017b; Silva et al. 2018) and method papers (Claessens et al. 2013; Collard et al. 2015; Dehaut et al. 2016) that the use of di ff erent chemical and physical treatments for the extraction of particles can in fl uence the e ff ectiveness of…”

“Recent studies have started to quantify indoor and out-door air MP levels, for example, Dris et al. (2017) reported concentrations of 1 : 0 – 60 MPs = m 3 (indoor) and 0 : 3 – 1 : 5 MPs = m 3 (outdoor) in air, whereas Liu et al. (2019) measured levels of 0 – 4 : 18 MPs = m 3 in outdoor air.”

“It has been argued in recent reviews (Miller et al. 2017; Lusher et al. 2017b; Silva et al. 2018) and method papers (Claessens et al. 2013; Collard et al. 2015; Dehaut et al. 2016) that the use of di ff erent chemical and physical treatments for the extraction of particles can in fl uence the e ff…”

“Using only visual observation for the identi fi cation of MP particles can lead to overestimations (Rocha-Santos and Duarte 2015; Strungaru et al. 2019; S Zhang et al. 2019).”

“MPs are ubiquitous in the environment, with marine environments especially a ff ected owing to the amount of plastic waste they receive (Burns and Boxall 2018; Gourmelon 2015; J Li et al. 2016).”

“The importance of the source (farmed or wild) has been high-lighted in previous research (Mathalon and Hill 2014).”

“…might be di ff erent and the internal doses of MPs are likely to vary and depend on the physicochemical MP characteristics (e.g., size, hydrophilicity) (Galloway 2015) and the responses of the barrier organ, that is, the GI tract (Keshav and Bailey 2013; Vancamelbeke and Vermeire 2017) and the…”

“It has been argued in recent reviews (Miller et al. 2017; Lusher et al. 2017b; Silva et al. 2018) and method papers (Claessens et al. 2013; Collard et al. 2015; Dehaut et al. 2016) that the use of di ff erent chemical and physical treatments for the extraction of particles can in fl uence the e ff…”

“Two studies (Akhbarizadeh et al. 2020; Karami et al. 2018) used canned samples (whole fi sh), and 1 (Karami et al. 2017b) used dried fi sh ( fl esh and organs) (Table 1).”

“Recently reported potential human e ff ects include GI and liver toxicity (Chang et al. 2020; W Wang et al. 2019) as well as neurotoxicity (Prüst et al. 2020).”

“In addition to food ingestion, atmospheric MP contamination presents an additional pathway for MP human exposures (Chen et al. 2020), related to direct exposures via inhalation (Wright et al. 2020) and indirect exposures via nondietary ingestion routes of hand-to-mouth behavior (Gasperi et al.…”

“In fl uence diagnostics included the I 2 and Q values (Baujat et al. 2002) and the contribution to the pooled e ff ect size (Viechtbauer and Cheung 2010).”

“For instance, the studies by De Witte et al. (2014) and Davidson and Dudas (2016) were rejected because a particle composition identi fi cation process was not included.”

“…human exposures (Chen et al. 2020), related to direct exposures via inhalation (Wright et al. 2020) and indirect exposures via nondietary ingestion routes of hand-to-mouth behavior (Gasperi et al. 2018), inadvertent ingestion (Abbasi et al. 2019), and occupational exposures (Gallagher et al. 2015).”

“…et al. 2020) provided the necessary data for meta-analysis of MP content per mass and fi ve (Digka et al. 2018; Feng et al. 2020; Lopes et al. 2020; Tanaka and Takada 2016; Q Wang et al. 2020) per individual organism, but all of them sampled di ff erent families/species of fi sh (Table 1), which…”

“Seafood is an important source of protein for populations around the world, and it may be time to implement the precautionary principle (Kriebel et al. 2001), based on the existing scienti fi c evidence, and take steps in policy, industry, and society to minimize human exposures to foodborne MPs…”

“In addition to food ingestion, atmospheric MP contamination presents an additional pathway for MP human exposures (Chen et al. 2020), related to direct exposures via inhalation (Wright et al. 2020) and indirect exposures via nondietary ingestion routes of hand-to-mouth behavior (Gasperi et al.…”

“MPs are ubiquitous in the environment, with marine environments especially a ff ected owing to the amount of plastic waste they receive (Burns and Boxall 2018; Gourmelon 2015; J Li et al. 2016).”

“There is a growing body of evidence regarding e ff ects in aquatic animals, but health e ff ects on humans are still unclear (Karbalaei et al. 2018; Sharma and Chatterjee 2017; Smith et al. 2018).”

“…used to enhance their attributes (plasticizers), the chemical contaminants absorbed while in the environment [e.g.,polycyclic aromatic hydrocarbons (Hartmann et al. 2017; Ziccardi et al. 2016) and pol-ychlorinated biphenyls (Engler 2012), or the microorganisms colonizing their surfaces (Vir…”

“There were only three studies (Fang et al. 2018; Hossain et al. 2020; J Wang et al. 2019) that provided the necessary data (Table 3).”

“…the levels of MPs in human subjects, are only recently being investigated, but there is a growing body of literature to support evidence of uptake (Abbasi et al. 2019; Gallagher et al. 2015; Schwabl et al. 2019) and detrimental impacts (Dong et al. 2020; Gallo et al. 2018; Stock et al. 2019).”

“Two recent reviews (Hantoro et al. 2019; Toussaint et al. 2019) presented evidence of human exposure to MP through the consumption of seafood but did not critically collate evidence in order to quantify MP uptake.”

“When needed, the conversion of the fi ve-number summary (sample minimum and maximum, median, lower and upper quartile) to the quantities needed for this review, was made using the methods and calculator developed by Shi et al. (2020).”

“…persistent particles; over time they have contaminated all compartments of marine ecosystems, including the food web and biota across di ff erent trophic levels, such as bivalves (SY Zhao et al. 2018), crustaceans (F Zhang et al. 2019), fi sh, and mammals (Lusher et al. 2015; Nelms et al. 2018).”

“There were only three studies (Fang et al. 2018; Hossain et al. 2020; J Wang et al. 2019) that provided the necessary data (Table 3).”

“Forest plot for random-e ff ects model results for mussels without the two high risk of bias (RoB) studies (Hermabessiere et al. 2019; SY Zhao et al. 2018).”

“…were rated as having a high RoB because they did not report the results for the analysis of their procedural blanks (Hermabessiere et al. 2019; HX Li et al. 2018; Thushari et al. 2017; J Wang et al. 2019; Webb et al. 2019; Wu et al. 2020; SY Zhao et al. 2018) (Table S7), an analysis step that…”

“…their attributes (plasticizers), the chemical contaminants absorbed while in the environment [e.g.,polycyclic aromatic hydrocarbons (Hartmann et al. 2017; Ziccardi et al. 2016) and pol-ychlorinated biphenyls (Engler 2012), or the microorganisms colonizing their surfaces (Vir (cid:1) sek et al.…”

“In contrast, other research and reviews report higher MP and plastic concentrations in the convergence zones of the subtropical gyres and higher concentrations in the open ocean than in coastal areas (Avio et al. 2017; Barrows et al. 2018; Cózar et al. 2014; Eriksen et al. 2014).”

“Recent reviews by Hermsen et al. (2018) and Koelmans et al. (2019) proposed quality assessment systems for MPs research regarding biota samples and water samples, respectively, similar to the RoB tool used in the present meta-analysis.”

“%) analyzed 100% of the particles (Cho et al. 2019; Ding et al. 2018, 2019, 2020; Nam et al. 2019; Phuong et al. 2018a; Webb et al. 2019; Wu et al. 2020), one 80% (Hermabessiere et al. 2019), and the rest 0.9 – 36% (Table S9).”

“The study by Renzi et al. (2019) used considerably larger samples (20 : 22 g ± 4 : 2) than Digka et al. (2018) (9 : 63 g ± 1 : 46), which would account for the higher MP content per individual.”

“Using only visual observation for the identi fi cation of MP particles can lead to overestimations (Rocha-Santos and Duarte 2015; Strungaru et al. 2019; S Zhang et al. 2019).”

“Only seven studies reported all the variables needed for the analysis (Hermabessiere et al. 2019; J Li et al. 2016, 2018; Phuong et al. 2018a; Su et al. 2018; Teng et al. 2019; Zhu et al. 2019) (Table S9).”

“Two studies reported the absence of MP contamination in seabass ( Lateolabrax maculatus ) (Su et al. 2019), in yellow croaker ( Larimichthys cro-cea ) and dotted gizzard shad ( Konosirus punctatus ) (Wu et al. 2020), whereas Akoueson et al. (2020) did not discover MP content signi fi cantly di ff…”

“Two studies did not provide the exact sample size: Qu et al. (2018) reported n ∼ 760 mussels and Wu et al. (2020) reported 10 – 20 samples for each species, and Teng et al. (2020) did not report sample sizes at all.”

“…is evidence that occupational exposure to high levels of airborne MPs can impact upon human health (Donaldson and Tran 2004; Gallagher et al. 2015; Pauly et al. 1998), but further research is needed to understand whether dietary MPs exposures can have a detrimental e ff ect on the human GI system.”

“Eighteen studies analyzed fi sh, with 4 reporting the discovery of MPs in the samples or the rate of discovery (Collard et al. 2017a; Karami et al. 2017b, 2018; Pozo et al. 2019) (Table 4).”

“Using only visual observation for the identi fi cation of MP particles can lead to overestimations (Rocha-Santos and Duarte 2015; Strungaru et al. 2019; S Zhang et al. 2019).”

“There were only three studies (Fang et al. 2018; Hossain et al. 2020; J Wang et al. 2019) that provided the necessary data (Table 3).”

“…attributes (plasticizers), the chemical contaminants absorbed while in the environment [e.g.,polycyclic aromatic hydrocarbons (Hartmann et al. 2017; Ziccardi et al. 2016) and pol-ychlorinated biphenyls (Engler 2012), or the microorganisms colonizing their surfaces (Vir (cid:1) sek et al. 2017)].”

“Two studies (Akhbarizadeh et al. 2020; Karami et al. 2018) used canned samples (whole fi sh), and 1 (Karami et al. 2017b) used dried fi sh ( fl esh and organs) (Table 1).”

“Only seven studies reported all the variables needed for the analysis (Hermabessiere et al. 2019; J Li et al. 2016, 2018; Phuong et al. 2018a; Su et al. 2018; Teng et al. 2019; Zhu et al. 2019) (Table S9).”

“Two studies (Akhbarizadeh et al. 2020; Karami et al. 2018) used canned samples (whole fi sh), and 1 (Karami et al. 2017b) used dried fi sh ( fl esh and organs) (Table 1).”

“…route with varying MP concentrations, such as sugar (0 : 44 MPs = g) (Cox et al. 2019), whereas in our previous work, salt was found to have an MP content of 0 – 1,674 MPs = kg (Danopoulos et al. 2020a), tap water 0 – 628 MPs = L, and bottled water 0 – 4,889 MPs = L (Danopoulos et al. 2020b).”

“…were rated as having a high RoB because they did not report the results for the analysis of their procedural blanks (Hermabessiere et al. 2019; HX Li et al. 2018; Thushari et al. 2017; J Wang et al. 2019; Webb et al. 2019; Wu et al. 2020; SY Zhao et al. 2018) (Table S7), an analysis step that…”

“For instance, the studies by De Witte et al. (2014) and Davidson and Dudas (2016) were rejected because a particle composition identi fi cation process was not included.”

“Only seven studies reported all the variables needed for the analysis (Hermabessiere et al. 2019; J Li et al. 2016, 2018; Phuong et al. 2018a; Su et al. 2018; Teng et al. 2019; Zhu et al. 2019) (Table S9).”

“%) analyzed 100% of the particles (Cho et al. 2019; Ding et al. 2018, 2019, 2020; Nam et al. 2019; Phuong et al. 2018a; Webb et al. 2019; Wu et al. 2020), one 80% (Hermabessiere et al. 2019), and the rest 0.9 – 36% (Table S9).”

“Using only visual observation for the identi fi cation of MP particles can lead to overestimations (Rocha-Santos and Duarte 2015; Strungaru et al. 2019; S Zhang et al. 2019).”

“…McGoran et al. 2018; Thushari et al. 2017; J Wang et al. 2019) did not report the similarity index of the spectral library, and only 44% ( n = 4) (Fang et al. 2018; Leslie et al. 2017; McGoran et al. 2018; Wu et al. 2020) reported the proportion of extracted particles analyzed for composition.”

“…consumption, with this emerging risk and the possible e ff ects on health, has raised concern in the scienti fi c community (Barboza et al. 2018; Diepens and Koelmans 2018; Santillo et al. 2017; Waring et al. 2018) as well as among stakeholders (GESAMP 2015, 2016) and policy makers globally…”

“Two recent reviews (Hantoro et al. 2019; Toussaint et al. 2019) presented evidence of human exposure to MP through the consumption of seafood but did not critically collate evidence in order to quantify MP uptake.”

“McGoran et al. (2018) reported that only 6% of their samples tested positive for MP contamination, F Zhang et al. (2019) reported the level to be 25%, and the study by Bour et al. (2018) elevated the level to 65%.”

“Key toxic mechanisms include cytotoxicity via oxidative stress (Chang et al. 2020), gene expression alteration and genotoxicity (YL Wang et al. 2020) changes to the gut microbiota (van Raamsdonk et al. 2020), metabolism disorders, and in fl ammatory reactions (Chang et al. 2020).”

“It has been argued in recent reviews (Miller et al. 2017; Lusher et al. 2017b; Silva et al. 2018) and method papers (Claessens et al. 2013; Collard et al. 2015; Dehaut et al. 2016) that the use of di ff erent chemical and physical treatments for the extraction of particles can in fl uence the e ff…”

“…this emerging risk and the possible e ff ects on health, has raised concern in the scienti fi c community (Barboza et al. 2018; Diepens and Koelmans 2018; Santillo et al. 2017; Waring et al. 2018) as well as among stakeholders (GESAMP 2015, 2016) and policy makers globally (EFSA Panel on…”

“It has been argued in recent reviews (Miller et al. 2017; Lusher et al. 2017b; Silva et al. 2018) and method papers (Claessens et al. 2013; Collard et al. 2015; Dehaut et al. 2016) that the use of di ff erent chemical and physical treatments for the extraction of particles can in fl uence the e ff…”

“The pattern of MPs contamination of the oceans (surface/ column water and sediments) has been the subject of intensive recent research, but their results are contradictory (Li et al. 2019; Olivatto et al. 2019; Pan et al. 2019; Yu et al. 2018; C Zhang et al. 2019; J Zhao et al. 2018).”

“Forest plot for random-e ff ects model for oysters, sensitivity analysis results without the high-risk of bias study (Baechler et al. 2020), and the statistical outlier of extremely large e ff ects (Abidli et al. 2019).”

“Two studies (Akhbarizadeh et al. 2020; Karami et al. 2018) used canned samples (whole fi sh), and 1 (Karami et al. 2017b) used dried fi sh ( fl esh and organs) (Table 1).”

“The pattern of MPs contamination of the oceans (surface/ column water and sediments) has been the subject of intensive recent research, but their results are contradictory (Li et al. 2019; Olivatto et al. 2019; Pan et al. 2019; Yu et al. 2018; C Zhang et al. 2019; J Zhao et al. 2018).”

“Only seven studies reported all the variables needed for the analysis (Hermabessiere et al. 2019; J Li et al. 2016, 2018; Phuong et al. 2018a; Su et al. 2018; Teng et al. 2019; Zhu et al. 2019) (Table S9).”

“Key toxic mechanisms include cytotoxicity via oxidative stress (Chang et al. 2020), gene expression alteration and genotoxicity (YL Wang et al. 2020) changes to the gut microbiota (van Raamsdonk et al. 2020), metabolism disorders, and in fl ammatory reactions (Chang et al. 2020).”

“…having a high RoB because they did not report the results for the analysis of their procedural blanks (Hermabessiere et al. 2019; HX Li et al. 2018; Thushari et al. 2017; J Wang et al. 2019; Webb et al. 2019; Wu et al. 2020; SY Zhao et al. 2018) (Table S7), an analysis step that was rated as one…”

“Birnstiel et al. (2019) concluded that depuration (over a 4-d period) signi fi cantly reduced MP content in their samples ( Perna perna ).”

“Only seven studies reported all the variables needed for the analysis (Hermabessiere et al. 2019; J Li et al. 2016, 2018; Phuong et al. 2018a; Su et al. 2018; Teng et al. 2019; Zhu et al. 2019) (Table S9).”

“Standardization cannot be achieved throughout all aspects of scienti fi c experimental protocols, but best practices for analytical procedures and quality assurance and control tools can be set as the minimum standard for designing, executing, and reporting experiments (Johnson et al. 2020).”

“There is evidence that occupational exposure to high levels of airborne MPs can impact upon human health (Donaldson and Tran 2004; Gallagher et al. 2015; Pauly et al. 1998), but further research is needed to understand whether dietary MPs exposures can have a detrimental e ff ect on the human GI…”

“Forest plot for random-e ff ects model for oysters, sensitivity analysis results without the high-risk of bias study (Baechler et al. 2020), and the statistical outlier of extremely large e ff ects (Abidli et al. 2019).”

“Five studies collected samples only from markets (Cho et al. 2019; Ding et al. 2019, 2020; Li et al. 2015; Akoueson et al. 2020), 3 from both the environment and markets (Ding et al. 2018; J Li et al. 2018; Van Cauwenberghe and Janssen 2014), and the other 23 from the environment (Table 1).”

“%) analyzed 100% of the particles (Cho et al. 2019; Ding et al. 2018, 2019, 2020; Nam et al. 2019; Phuong et al. 2018a; Webb et al. 2019; Wu et al. 2020), one 80% (Hermabessiere et al. 2019), and the rest 0.9 – 36% (Table S9).”

“Five studies collected samples only from markets (Cho et al. 2019; Ding et al. 2019, 2020; Li et al. 2015; Akoueson et al. 2020), 3 from both the environment and markets (Ding et al. 2018; J Li et al. 2018; Van Cauwenberghe and Janssen 2014), and the other 23 from the environment (Table 1).”

“Only the study by Zitouni et al. (2020) reported a content of 2 : 9 ± 1 : 54 MPs = g in painted comber ( Serranus scriba ).”

“Key toxic mechanisms include cytotoxicity via oxidative stress (Chang et al. 2020), gene expression alteration and genotoxicity (YL Wang et al. 2020) changes to the gut microbiota (van Raamsdonk et al. 2020), metabolism disorders, and in fl ammatory reactions (Chang et al. 2020).”

“Eighteen studies analyzed fi sh, with 4 reporting the discovery of MPs in the samples or the rate of discovery (Collard et al. 2017a; Karami et al. 2017b, 2018; Pozo et al. 2019) (Table 4).”

“Five studies collected samples only from markets (Cho et al. 2019; Ding et al. 2019, 2020; Li et al. 2015; Akoueson et al. 2020), 3 from both the environment and markets (Ding et al. 2018; J Li et al. 2018; Van Cauwenberghe and Janssen 2014), and the other 23 from the environment (Table 1).”

“Only 3 of the studies reported the weight of the samples used (Digka et al. 2018; Renzi et al. 2019; Sun et al. 2019), allowing a conversion from MP content per individual to MP content per mass (Table S12).”

“The pattern of MPs contamination of the oceans (surface/ column water and sediments) has been the subject of intensive recent research, but their results are contradictory (Li et al. 2019; Olivatto et al. 2019; Pan et al. 2019; Yu et al. 2018; C Zhang et al. 2019; J Zhao et al. 2018).”

“Eighteen studies analyzed fi sh, with 4 reporting the discovery of MPs in the samples or the rate of discovery (Collard et al. 2017a; Karami et al. 2017b, 2018; Pozo et al. 2019) (Table 4).”

“…et al. 2020; Zitouni et al. 2020) provided the necessary data for meta-analysis of MP content per mass and fi ve (Digka et al. 2018; Feng et al. 2020; Lopes et al. 2020; Tanaka and Takada 2016; Q Wang et al. 2020) per individual organism, but all of them sampled di ff erent families/species of fi sh…”

“Although the fi ndings are in some cases contradicting (van Raamsdonk et al. 2020) and further research is undoubtedly needed, there is also no evidence that MP human exposure is safe (Leslie and Depledge 2020).”

“In addition, Karbalaei et al. (2020) identi fi ed MP contamination in three brands of commercial fi shmeal; the use of such fi shmeal could have cumulative e ff ects in farmed seafood (Karbalaei et al. 2020).”

“Two studies did not provide the exact sample size: Qu et al. (2018) reported n ∼ 760 mussels and Wu et al. (2020) reported 10 – 20 samples for each species, and Teng et al. (2020) did not report sample sizes at all.”

“The results for the echinodermata phylum (Feng et al. 2020) are presented in Table 2 along with the molluskan phylum.”

“Overall assessment of the certainty of the evidence was based on the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework (Higgins et al. 2019) and the Environmental-GRADE (Bilotta et al. 2014) across fi ve domains, categorized into four certainty ratings: high, moderate, low, and very…”

“…and models executing all analysis via RStudio (version 1.2.1335; RStudio), using the additional packages meta (version 4.9-7; Schwarzer 2019), metaphor (version 2.1-0; Viechtbauer 2010), dmetar (Harrer et al. 2019a), robvis (McGuinness and Kothe 2019), and ggplot2 (Wickham et al. 2016).”

“The results of the studies were weighted using the inverse of the variance method (Chen and Peace 2013).”

“…route with varying MP concentrations, such as sugar (0 : 44 MPs = g) (Cox et al. 2019), whereas in our previous work, salt was found to have an MP content of 0 – 1,674 MPs = kg (Danopoulos et al. 2020a), tap water 0 – 628 MPs = L, and bottled water 0 – 4,889 MPs = L (Danopoulos et al. 2020b).”

“%) analyzed 100% of the particles (Cho et al. 2019; Ding et al. 2018, 2019, 2020; Nam et al. 2019; Phuong et al. 2018a; Webb et al. 2019; Wu et al. 2020), one 80% (Hermabessiere et al. 2019), and the rest 0.9 – 36% (Table S9).”

“McGoran et al. (2018) reported that only 6% of their samples tested positive for MP contamination, F Zhang et al. (2019) reported the level to be 25%, and the study by Bour et al. (2018) elevated the level to 65%.”