title: Dioxins, PCBs, chlorinated pesticides and brominated flame retardants in free-range chicken eggs from peri-urban areas in Arusha, Tanzania: Levels and implications for human health.
abstract: The environment in the northern part of Tanzania is influenced by rapid population growth, and increased urbanization. Urban agriculture is common and of economic value for low income families. In Arusha, many households sell eggs from free-ranging backyard chicken. In 2011, 159 eggs from different households in five different locations in Arusha were collected, homogenized, pooled into 28 composite samples and analyzed for a wide selection of POPs. Levels of POPs varied widely within and between the locations. The levels of dieldrin and ΣDDT ranged between 2 and 98,791 and 2 and 324ng/g lipid weight (lw), respectively. EU MRLs of 0.02mg/kg dieldrin for eggs were exceeded in 4/28 samples. PCBs, HCHs, chlordanes, toxaphenes and endosulfanes were found at lower frequency and levels. Brominated flame retardants (BFRs), e.g polybrominated diphenylethers (PBDEs), hexabromocyclododecane (HBCD) and 1,2-bis(2,4,6-tribromphenoxy)ethane (BTBPE) were present in 100%, 60% and 46% of the composite samples, respectively. Octa-and deca-BDEs were the dominating PBDEs and BDE 209 levels ranged between <LOQ (limit of quantification) - 312ng/g lw. Dioxins were measured using the DR-LUC bio-assay and found in levels of <LOQ - 20pg bio-TEQs/g lw. Four samples (13%) exceeded the maximum level of 5pg/g total WHO-TEQs for hen eggs set by the Commission Regulation (EU) No 1259/2011. The daily/weekly intake was calculated and risk was characterized for all compounds comparing with available toxicity reference values (TRVs) such as the provisional tolerable intake (PTDI) or Reference Doses (RfDs). In one sample dieldrin exceeded the PTDI (100ng/kgbw/day). Correlation was found between bio-TEQs and lipid adjusted levels of ΣPBDEs, suggesting similar sources. Open fires in backyards may be one of the sources for contamination of eggs with BFRs and dioxins.
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, NMBU, Campus Adamstuen, P.O. Box 8146 Dep, N-0033 Oslo, Norway.
authors.forename: A
authors.initials: A
authors.lastname: Polder
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, NMBU, Campus Adamstuen, P.O. Box 8146 Dep, N-0033 Oslo, Norway.
authors.forename: M B
authors.initials: MB
authors.lastname: Müller
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, NMBU, Campus Adamstuen, P.O. Box 8146 Dep, N-0033 Oslo, Norway.
authors.forename: O B
authors.initials: OB
authors.lastname: Brynildsrud
authors.affiliation: Institute for Environmental Studies (IVM), VU University Amsterdam, 1081HV Amsterdam, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: de Boer
authors.affiliation: Institute for Environmental Studies (IVM), VU University Amsterdam, 1081HV Amsterdam, The Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Hamers
authors.affiliation: Institute for Environmental Studies (IVM), VU University Amsterdam, 1081HV Amsterdam, The Netherlands.
authors.forename: J H
authors.initials: JH
authors.lastname: Kamstra
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, NMBU, Campus Adamstuen, P.O. Box 8146 Dep, N-0033 Oslo, Norway; Norwegian Institute for Water Research (NIVA), Gaustadallèen 21, N-0349 Oslo, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Lie
authors.affiliation: Sokoine University of Agriculture, Department of Veterinary Medicine and Public Health, P.O. Box 3021, Morogoro, Tanzania.
authors.forename: R H
authors.initials: RH
authors.lastname: Mdegela
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, NMBU, Campus Adamstuen, P.O. Box 8146 Dep, N-0033 Oslo, Norway.
authors.forename: H
authors.initials: H
authors.lastname: Moberg
authors.affiliation: Sokoine University of Agriculture, Department of Veterinary Medicine and Public Health, P.O. Box 3021, Morogoro, Tanzania.
authors.forename: H E
authors.initials: HE
authors.lastname: Nonga
authors.affiliation: The Norwegian Veterinary Institute (NVI), P.O. Box 750 Sentrum, N-0106 Oslo, Norway.
authors.forename: M
authors.initials: M
authors.lastname: Sandvik
authors.affiliation: The Norwegian Veterinary Institute (NVI), P.O. Box 750 Sentrum, N-0106 Oslo, Norway.
authors.forename: J U
authors.initials: JU
authors.lastname: Skaare
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, NMBU, Campus Adamstuen, P.O. Box 8146 Dep, N-0033 Oslo, Norway.
authors.forename: J L
authors.initials: JL
authors.lastname: Lyche
mesh_terms: D000818:Animals; D002645:Chickens; D004147:Dioxins / Q000032:analysis*; D004531:Eggs / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D005260:Female; D005411:Flame Retardants / Q000032:analysis*; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000032:analysis; D018811:Maternal Exposure; D010575:Pesticides / Q000032:analysis*; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D018570:Risk Assessment; D013636:Tanzania
chemical_list: D004147:Dioxins; D004785:Environmental Pollutants; D005411:Flame Retardants; D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D011078:Polychlorinated Biphenyls
keywords: Chicken eggs; Daily intake; Dioxins; Free-range; POPs; Tanzania