TY - JOUR
KW - Indoor environment department
KW - Pollutant fate and transport modeling
KW - Exposure and health effects
KW - Kow
KW - Biotransfer factor
KW - Btf
KW - Carry over rate
KW - Cattle
KW - Cor
KW - Cow
KW - Dairy
KW - Meat
KW - Milk
KW - Environmental Chemistry, Exposure and Risk Group
AU - Ralph K Rosenbaum
AU - Thomas E McKone
AU - Olivier Jolliet
AB - The objective of this study is to increase the understanding and transparency of chemical biotransfer modeling into meat and milk and explicitly confront the uncertainties in exposure assessments of chemicals that require such estimates. In cumulative exposure assessments that include food pathways, much of the overall uncertainty is attributable to the estimation of transfer into biota and through food webs. Currently, the most commonly used meat and milk-biotransfer models date back two decades and, in spite of their widespread use in multimedia exposure models few attempts have been made to advance or improve the outdated and highly uncertain Kow regressions used in these models. Furthermore, in the range of Kow where meat and milk become the dominant human exposure pathways, these models often provide unrealistic rates and do not reflect properly the transfer dynamics. To address these issues, we developed a dynamic three-compartment cow model (called CKow), distinguishing lactating and non-lactating cows. For chemicals without available overall removal rates in the cow, a correlation is derived from measured values reported in the literature to predict this parameter from Kow. Results on carry over rates (COR) and biotransfer factors (BTF) demonstrate that a steady-state ratio between animal intake and meat concentrations is almost never reached. For meat, empirical data collected on short term experiments need to be adjusted to provide estimates of average longer term behaviors. The performance of the new model in matching measurements is improved relative to existing models—thus reducing uncertainty. The CKow model is straight forward to apply at steady state for milk and dynamically for realistic exposure durations for meat COR.
BT - Environmental Science and Technology
C1 - 7.1, 7.2
C2 - LBNL-2370E
LA - eng
M1 - 21
N2 - The objective of this study is to increase the understanding and transparency of chemical biotransfer modeling into meat and milk and explicitly confront the uncertainties in exposure assessments of chemicals that require such estimates. In cumulative exposure assessments that include food pathways, much of the overall uncertainty is attributable to the estimation of transfer into biota and through food webs. Currently, the most commonly used meat and milk-biotransfer models date back two decades and, in spite of their widespread use in multimedia exposure models few attempts have been made to advance or improve the outdated and highly uncertain Kow regressions used in these models. Furthermore, in the range of Kow where meat and milk become the dominant human exposure pathways, these models often provide unrealistic rates and do not reflect properly the transfer dynamics. To address these issues, we developed a dynamic three-compartment cow model (called CKow), distinguishing lactating and non-lactating cows. For chemicals without available overall removal rates in the cow, a correlation is derived from measured values reported in the literature to predict this parameter from Kow. Results on carry over rates (COR) and biotransfer factors (BTF) demonstrate that a steady-state ratio between animal intake and meat concentrations is almost never reached. For meat, empirical data collected on short term experiments need to be adjusted to provide estimates of average longer term behaviors. The performance of the new model in matching measurements is improved relative to existing models—thus reducing uncertainty. The CKow model is straight forward to apply at steady state for milk and dynamically for realistic exposure durations for meat COR.
PY - 2009
EP - 8191–8198
T2 - Environmental Science and Technology
TI - CKow – A More Transparent and Reliable Model for Chemical Transfer to Meat and Milk
VL - 43
ER -