ASSESSING PUBLIC EXPOSURE TO PESTICIDE-CONTAMINATED GROUND-WATER

Long-term exposure assessments regarding four commonly used pesticides are presented in this paper. Alachlor, aldicarb, lindane, and parathion have been detected in ground-water monitoring wells. A multimedia transport model is employed to predict the long-term fate of these chemicals in the environment. Concentrations in each environmental compartment are calculated and used to determine the dominant exposure pathways and hence dose rate. Aldicarb is shown to move from the upper soil compartment, through the lower soil compartment, and accumulate at a rate which is several orders of magnitude greater than the other pesticides. Lindane moves faster to the biota compartment than the other pesticides. The dominant exposure pathway for aldicarb and alachlor is drinking water ingestion for both adults and children. For lindane and parathion, the dominant exposure pathway is biota ingestion for children and fish ingestion for adults. The methods presented in this paper can be used as screening tools for designing remediation, mitigation, or interdiction measures and can serve as a basis for evaluating risk management strategies.