title: Polybrominated diphenyl ethers: Residence time in soils receiving biosolids application.
abstract: Polybrominated diphenyl ethers (PBDEs) may enter the environment because of accumulation in biosolids followed by application to agricultural lands. No published dissipation studies are available for PBDEs in agricultural soils after biosolids application. Therefore, we conducted a 3-year study to examine the fate of PBDEs in a small-scale 0.24-ha continuously cropped field after a single biosolids application at 72.3 wet tons/ha and determined dissipation half-lives for BDE-47+BDE-99 and BDE-209. In addition, we conducted a large-scale survey of soils from 26 mostly pasture fields at 10 farms with detailed information on timing and rate of biosolids applications. In the small-scale experiment, maximum soil PBDE concentrations of 43.7 ± 42.7 μg kg-1d.w. for BDE-209 and 6.05 ± 7.15 μg kg-1d.w. for BDE-47+BDE-99 were reached 1 year after application. We hypothesized that PBDEs were slowly released from the biosolids matrix into the soil over the first year. After 3 years, median BDE-47+BDE-99 concentrations were approximately equal to preapplication levels, whereas median BDE-209 concentrations remained ∼129% above preapplication levels. The estimated residence time from the small-scale experiment was 342 d for BDE-47+BDE-99 and 861 d for BDE-209. In the large-scale study, a subset of fields that received a single biosolids application was used to generate another estimate of residence time: 704 d for BDE-47+BDE-99 and 1440 d for BDE-209. These longer residence time estimates were used in three different first-order decay dissipation scenarios (continuous, limited, and no dissipation) to predict PBDE concentration in fields with single and multiple biosolids applications. Results indicate that dissipation occurs primarily in the first 2 years after application, but residues remaining in the soil after this period are likely to be much more tightly bound and less available for degradation.
authors.affiliation: Department of Civil and Environmental Engineering, University of Maryland, 1153 Martin Hall, College Park, MD 20742, USA. Electronic address: nandrade@umd.edu.
authors.forename: Natasha A
authors.initials: NA
authors.lastname: Andrade
authors.affiliation: Department of Civil and Environmental Engineering, University of Maryland, 1153 Martin Hall, College Park, MD 20742, USA.
authors.forename: Laura L
authors.initials: LL
authors.lastname: McConnell
authors.affiliation: Department of Civil and Environmental Engineering, University of Maryland, 1153 Martin Hall, College Park, MD 20742, USA.
authors.forename: Marya O
authors.initials: MO
authors.lastname: Anderson
authors.affiliation: Department of Civil and Environmental Engineering, University of Maryland, 1153 Martin Hall, College Park, MD 20742, USA.
authors.forename: Alba
authors.initials: A
authors.lastname: Torrents
authors.affiliation: District of Columbia Water and Sewer Authority, 5000 Overlook Avenue, S.W. Washington, District of Columbia 20032, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Ramirez
mesh_terms: D004784:Environmental Monitoring; D055768:Halogenated Diphenyl Ethers / Q000032:analysis*; D012722:Sewage / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D013997:Time Factors
chemical_list: C477694:2,2',4,4',5-brominated diphenyl ether; D055768:Halogenated Diphenyl Ethers; D012722:Sewage; D012987:Soil; D012989:Soil Pollutants; C511295:2,2',4,4'-tetrabromodiphenyl ether; C010902:decabromobiphenyl ether
keywords: BDE-209; Biosolids; Half-life; PBDEs; Residence time; Soil