Using Publicly Available Air and Water Monitoring Data to Estimate Childhood Exposure to 1,1-Dichloroethene for the Voluntary Children's Chemical Exposure Program

摘要

1,1-Dichloroethene (CAS# 75-35-4, vinylidene chloride, VDC) has been selected for evaluation in the pilot for the USEPA Voluntary Children's Chemical Evaluation Program (VCCEP) and the Dow Chemical Company has volunteered to sponsor this chemical through the program. A goal of this program is to fulfill the EPA commitment to "...review and report on what new testing may be needed to assess the special impact industrial chemicals may have on children." The VCCEP specifies that both existing exposure and hazard data be collected and submitted for review to aid the EPA determination of what new data may be needed. The sponsor collects or develops health effects and exposure information and integrates it into a risk assessment and a data needs assessment, these are peer reviewed and submitted to the agency. As part of this commitment the potential exposures of children are evaluated using readily available air and water monitoring data. These monitoring data are combined with child specific exposure factors (e.g. body weight, water consumption rates, inhalation rates) to give a robust exposure assessment. The inhalation and oral drinking water exposures are estimated using Monte Carlo techniques. These require the choice of the age categories for children, and a determination of the sampling duration, the time between samples and the spatial scale of the monitoring data. To evaluate the estimated exposure it is compared to an established health benchmark, the USEPA reference dose of 50 mug/kg/day. The average child exposure from water is 0.009 mug/kg/day. The maximum estimated childhood exposure from water was 0.40 mug/kg/day. The average calculated childhood inhalation exposure is 0.16 mug/kg/day. All estimated exposures are a small fraction of the USEPA reference dose.