Pharmaceuticals and personal care products in archived U.S. biosolids from the 2001 EPA national sewage sludge survey

Abstract

In response to the U.S. National Academies’ call for a better assessment of chemical pollutants contained in the approximately 6.9 million dry tons of digested municipal sludge produced annually in the United States, the mean concentration of 72 pharmaceuticals and personal care products (PPCP) were determined in 110 biosolids samples collected by the U.S. Environmental Protection Agency (EPA) in its 2001 National Sewage Sludge Survey. Composite samples of archived biosolids, collected at 94 U.S. wastewater treatment plants from 32 states and the District of Columbia, were analyzed by liquid chromatography tandem mass spectrometry using EPA Method 1694. Thirty-eight (54%) of the 72 analytes were detected in at least one composite sample at concentrations ranging from 0.002 to 48 mg kg−1 dry weight. Triclocarban and triclosan were the most abundant analytes with mean concentrations of 36 ± 8 and 12.6 ± 3.8 mg kg−1 (n = 5), respectively, accounting for 65% of the total PPCP mass found. The loading to U.S. soils from nationwide biosolids recycling was estimated at 210–250 metric tons per year for the sum of the 72 PPCPs investigated. The results of this nationwide reconnaissance of PPCPs in archived U.S. biosolids mirror in contaminant occurrences, frequencies and concentrations, those reported by the U.S. EPA for samples collected in 2006/07. This demonstrates that PPCP releases in U.S. biosolids have been ongoing for many years and the most abundant PPCPs appear to show limited fluctuations in mass over time when assessed on a nationwide basis. The here demonstrated use of five mega composite samples holds promise for conducting cost-effective, routine monitoring on a regional basis.