%0 Journal Article
%@ 1552-9924
%A Gyalpo, Tenzing
%A Toms, Leisa-Maree
%A Mueller, Jochen F.
%A Harden, Fiona A.
%A Scheringer, Martin
%A Hungerbuhler, Konrad
%D 2015
%F quteprints:92537
%I National Institute of Environmental Health Sciences
%J Environmental Health Perspectives
%K polybrominated diphenyl ethers
%K biological monitoring
%K environmental exposure
%K environmental impact assessment
%N 10
%P 978-984
%R 10.1289/ehp.1408960
%T Insights into PBDE uptake, body burden, and elimination gained from Australian age–Concentration trends observed shortly after peak exposure
%U https://eprints.qut.edu.au/92537/
%V 123
%X Background    Population pharmacokinetic models combined with multiple sets of age– concentration biomonitoring data facilitate back-calculation of chemical uptake rates from biomonitoring data.     Objectives    We back-calculated uptake rates of PBDEs for the Australian population from multiple biomonitoring surveys (top-down) and compared them with uptake rates calculated from dietary intake estimates of PBDEs and PBDE concentrations in dust (bottom-up).     Methods    Using three sets of PBDE elimination half-lives, we applied a population pharmacokinetic model to the PBDE biomonitoring data measured between 2002–2003 and 2010–2011 to derive the top-down uptake rates of four key PBDE congeners and six age groups. For the bottom-up approach, we used PBDE concentrations measured around 2005.     Results    Top-down uptake rates of Σ4BDE (the sum of BDEs 47, 99, 100, and 153) varied from 7.9 to 19 ng/kg/day for toddlers and from 1.2 to 3.0 ng/kg/day for adults; in most cases, they were—for all age groups—higher than the bottom-up uptake rates. The discrepancy was largest for toddlers with factors up to 7–15 depending on the congener. Despite different elimination half-lives of the four congeners, the age–concentration trends showed no increase in concentration with age and were similar for all congeners.     Conclusions    In the bottom-up approach, PBDE uptake is underestimated; currently known pathways are not sufficient to explain measured PBDE concentrations, especially in young children. Although PBDE exposure of toddlers has declined in the past years, pre- and postnatal exposure to PBDEs has remained almost constant because the mothers’ PBDE body burden has not yet decreased substantially.