es9b04130_si_001.pdf (1.38 MB)
Clarifying Temporal Trend Variability in Human Biomonitoring of Polybrominated Diphenyl Ethers through Mechanistic Modeling
journal contribution
posted on 2019-12-12, 23:29 authored by Li Li, Christopher Hoang, Jon A. Arnot, Frank WaniaHuman biomonitoring data collected from individuals of the same age sampled
in different years provide within-age temporal trends, which are often
employed to evaluate the effectiveness of chemical regulatory policies.
For polybrominated diphenyl ethers (PBDEs), this within-age temporal
trend has been observed to vary between congeners and age groups.
We systematically explore the mechanisms responsible for such variability
through simulating human exposure via multiple exposure pathways to
PBDEs released from multiple lifecycle stages. Our simulation indicates
that, after new use of PBDEs is banned, emissions to the outdoor environment
from use and waste disposal outlast those to the indoor environment
from the indoor use phase, leading to slower decline rates in the
contamination of food items sourced from the outdoor environment than
that from indoors. Compared with indoor exposure pathways, the consumption
of contaminated food contributes more to the exposure (i) to more
hydrophobic, recalcitrant congeners, and (ii) of adults than children,
which results in slower rates of decline in the within-age temporal
trend of those congeners and in adults. The within-age temporal trend is influenced to a lesser extent
by the elimination of PBDEs from the human body, e.g., differences
in biotransformation potential of congeners, growth dilution, and
pre- and postnatal exposures by children.