Brominated flame retardants in U.S. biosolids from the EPA national sewage sludge survey and chemical persistence in outdoor soil mesocosms

Abstract

We determined national baseline levels and release inventories of 77 traditional and novel brominated flame retardants (BFRs) in biosolids composites (prepared from 110 samples) from the U.S. Environmental Protection Agency’s 2001 national sewage sludge survey (NSSS). Additionally, analyses were performed on archived samples from a 3-year outdoor mesocosm study to determine the environmental persistence of BFRs in biosolids-amended soil. The total polybrominated diphenylether (PBDE) concentration detected in biosolids composites was 9,400±960 μg/kg dry weight, of which deca-BDE constituted 57% followed by nona- and penta-BDE at 18 and 13%, respectively. The annual mean loading rate estimated from the detected concentrations and approximate annual biosolids production and disposal numbers in the U.S., of the sum of PBDEs and non-BDE BFRs was calculated to be 47,900–60,100 and 12,900–16,200 kg/year, of which 24,000–36,000 and 6,400–9,700 kg/year are applied on land, respectively. Mean concentration of PBDEs were higher in the 2001 samples compared to levels reported in EPA’s 2006/7 Targeted NSSS, reflecting on-going efforts in phasing-out PBDEs in the U.S. In outdoor soil mesocosms, >99% of the initial BFRs mass in the biosolids/soil mixtures (1:2) persisted over the monitoring duration of three years. Estimates of environmental releases may be refined in the future by analyzing individual rather than composited samples, and by integrating currently unavailable data on disposal of biosolids on a plant-specific basis. This study informs the risk assessment of BFRs by furnishing national inventories of BFR occurrence and environmental release via biosolids application on land.

Occurrence and distribution of brominated flame retardants and perfluoroalkyl substances in Australian landfill leachate and biosolids

“…The ratios of BDE-99 to BDE-47 were consistent between all samples (mean 1.13; %CV 14) and with the ratio found in the commercial formulation (1.17) [32], suggesting a common source, little degradation of congeners during the various treatment processes or similar sorption to solid matter. The detection of BDE-209, −99 and −47 as the dominant congeners in this study matches that described in numerous international studies assessing the PBDE content of biosolids [33][34][35][36].…”

“…Extensive international comparisons of PBTs in biosolids have been made previously, with levels ranging greatly worldwide [31,84,85]. Levels of HBCDD detected in this study (<LOD-129 ng/g) are similar to those detected recently in Spain (<LOD-97.5 ng/g) [84], China (0.09-66 ng/g) [86,87] and the USA (19.8 ng/g) [36]. Levels of PFOS detected in the current study are lower than maximums detected in Switzerland (2440 ng/g) [38], Spain (1790 ng/g) [88] and the USA (403 ng/ g) [89] and similar to levels detected in Finland (16-110 ng/g) [90].…”

Occurrence and estrogenic potency of eight bisphenol analogs in sewage sludge from the U.S. EPA targeted national sewage sludge survey

“…In that study, SS samples were collected from 74 POTWs that employ secondary treatment or better in 2006/2007 [35]. Several pollutants have been analyzed 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 5 in these samples and the results have been published [29,[36][37][38][39]. However, no earlier study has reported the occurrence of bisphenols in SS from nationally representative samples.…”

Dynamics of brominated flame retardants removal in contaminated wastewater sewage sludge under anaerobic conditions

“…In Europe in 2004, and in the USA in 2006, PentaBDE and OctaBDE mixtures were phased out from production due to concern over observed toxic effects (EPA U, 2006;EU, 2003). This led to temporarily increases in the production of DecaBDE mixtures, resulting in elevated concentrations of BDE 209 (the major congener in DecaBDE mixture) and decreasing concentrations of BDE 154 and BDE 183 (representative of PentaBDE and OctaBDE mixtures) in environmental samples (Law et al, 2014;Venkatesan and Halden, 2014). Following the restriction of the use of PBDE mixtures, there was also an increase in the production and usage of HBCD (Al-Odaini et al, 2015;Law et al, 2006).…”

“…Sewage treatment plants have been reported as one of the major sources of BFR pollution through the discharge of wastewater effluents and subsequent usage of sewage sludge (Gorga et al, 2013;Venkatesan and Halden, 2014). The most common methods of sludge use and disposal are agriculture, compost, landfilling and incineration.…”