Diet and indoor environments as predictors of human body burden of PBDE

Legislation requiring flame retardants to be added to soft furniture and electronic items since the 1970s has saved many lives. Brominated Flame Retardants (BFRs) including Poly Brominated Diphenyl Ethers (PBDEs) are now ubiquitous in the environment and bio-accumulate. The Stockholm Convention (2004) requires signatories to reduce or eliminate releases of unintentionally and intentionally produced Persistent Organic Pollutants (POPs) to protect human health and the environment. Emerging POPs such as PBDEs may soon be included in the 'dirty dozen'. Little is known about the magnitude and exposure pathways of PBDEs. They are released during manufacture, recycling and incineration processes, can leach from treated materials into the atmosphere and can be absorbed by dermal contact. The human body burden of PBDE has doubled every five years for the past 30 years. PBDEs are lipophilic, accumulating in human fatty tissue. Transfer from mother to child occurs during breast feeding. Young children spending time on carpets and exhibiting frequent hand to mouth behaviour are known to have increased body burden. Another route of exposure to POPs is via food such as oily fish, meat and dairy. The potential human health effects of PBDE exposure and body burden are reproductive toxicity, neurotoxicity, immune effects and carcinogenicity. A risk assessment incorporating all potential sources, pathways and receptors can be expressed as a Conceptual Exposure Model (CEM). The hypotheses of this research are: 1. PBDE concentrations in dust and air can be predicted from room or vehicle contents (e.g. number/age of computers/carpeting); 2. CEMs including diet, indoor environments and behaviours can be used to predict body burdens of PBDE; 3. Indoor exposures to PBDE are an important contributor to overall exposure; (for legacy POPs diet is the major source); 4. The distribution of PBDEs between compartments such as blood and breast milk is determined by their physico-chemical properties. The programme will further the understanding of degradation and metabolism of PBDEs and correlate sources of PBDE in environmental and human samples. During the research process mathematical models will be developed to predict future exposures under a variety of scenarios. The final research outcomes will be evidence based exposure management strategies and risk assessments. Co-habiting couples who have not moved house or changed employment for at least 2 years will be recruited. Using such couples will allow sampling and analysis of shared diet and indoor environments and identification of differences resulting from behaviours such as computer gaming or work exposures. Body burden will be assessed from blood samples. Diet, indoor air and dust samples will be assessed and comprehensive questionnaires and surveys will be used to create the CEMs. PBDE concentrations in dust and air will be predicted using comprehensive surveys of room or vehicle contents. Approximately half the training and all fieldwork will be based Newcastle University's Institute of Health and Society. Birmingham University's Division of Environmental Health and Risk Management will provide training in monitoring and sampling of indoor air environments as well as expertise in flame retardants research. The Food Science Group at Central Science Laboratory will provide technical training in diet studies and exposure assessment methodology as well as analytical chemistry techniques. The collaboration of these research centres, each at the forefront of their field, is driven by the need for an holistic approach to POPs investigation and modelling. Through this capacity building programme the student will gain valuable experience in multidisciplinary research and collaboration whilst pioneering a new approach to BFR exposure characterisation. The association with the NERC POPs Network provides fertile ground for dissemination of results and further research opportunities.