Appendix D Food Codes for NHANES - OEHHA

Scientific Review PanelSRP Draft Version 2 February,June 2012
Since this document supports risk assessments conducted under the Air Toxics
Hot Spots program, we are primarily discussing Hot Spots chemicals emitted
from stationary sources.
Many of these persistent chemicals are ubiquitous in the environment and are
global pollutants found in low concentrations in air, water and soil. Because some
of these chemicals bio-concentrate in animal fat, the primary pathway of
exposure to breastfeeding mothers would be consumption of animal products
such as meat, milk, and eggs. Nearby polluting facilities can be a local source of
exposure and can add to the mother’s body burden of contaminants from global
pollution through multiple pathways.
This appendix develops lactational transfer coefficients for use in estimating the
concentration of a multipathway chemical in mother’s milk from an estimate of
chronic incremental daily dose to the mother from local stationary sources.
OEHHA derived human lactation transfer coefficients from studies that measured
contaminants in human milk and daily intake from inhalation or oral routes of
exposure from global pathways (e.g. air, cigarette smoke or diet) in the same or a
similar human population.
Briefly, human milk transfer coefficients (Tcohm) represent the transfer
relationship between the chemical concentration found in milk and the mother’s
chronic daily dose (i.e. concentration (µg/kg-milk)/dose (µg/kg/day) under steady
state conditions. In its simplest form, the biotransfer factor is:
Tcohm = Cm / Dt (Eq. J-1)
where:
Tcohm = transfer coefficient from ingested and inhaled media (day/kg)
Cm = concentration of chemical in mother’s milk (µg/kg-milk)
Dt = total maternal dose through all exposure routes (µg/day)
Equation J-2 estimates the concentration of contaminants in mother’s milk by
incorporating the Tco in the following way:
Cm = [DOSEair + DOSEwater + DOSEfood + DOSEsoil + DOSEdermal
D_inh + Dwi + Dfood + Dsi + Dderm] x Tcohm x BW (Eq. J-2)
where:
BW = the body weight of the mother at age 25 (default = 70.7 kg)
DOSEairDinh = dose to the mother through inhalation (µg/kg-BW-day)
DOSEwater Dwi = dose to the mother though drinking water ingestion
(µg/kg-BW-day)
DOSEfoodDfood = dose to the mother through ingestion of food sources
J-3