Abstract |
In October 2001, Office of Pesticide Programs (OPP) presented a proposed deterministic exposure assessment approach, specific to Chromated Copper Arsenate (CCA), to the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Scientific Advisory Panel (SAP). One of the primary SAP recommendations was to use a probabilistic model to predict variability of absorbed doses for the population of interest. Following the SAP meeting, OPP requested assistance from ORD in developing a probabilistic modeling methodology using National Exposure Research Laboratory's (NERL's) physically-based, Monte Carlo probabilistic Stochastic Human Exposure and Dose Simulation (SHEDS) model. The SHEDS model was refined specifically for the wood preservative scenario, in a version called SHEDS-Wood, and the SHEDS-Wood methodology was presented to the August 30, 2002 SAP. This assessment presents results for absorbed doses (both average daily doses (ADDs) and lifetime average daily doses (LADDs)); it does not report risk estimates. OPP has conducted a separate risk analysis and written a report on children's risks to CCA using the exposure and dose results from the SHEDS-Wood analyses presented here. The draft CCA exposure and risk assessments were presented to the SAP in December 2003. Recommendations from all three SAPs have been incorporated to the extent possible in the SHEDS-Wood code, inputs, and methodology to yield the CCA assessment presented in this final report. |