Quantitative examination of major pathways and routes of exposure to pesticides is essential for determining human risk. The current study was conducted in two apartments and examines the accumulation of the pesticide chlorpyrifos in childrens' toys after the time suggested for reentry after application. It has been established for the first time that a semivolatile pesticide will accumulate on and in toys and other sorbant surfaces in a home via a two-phase physical process that continues for at least 2 weeks postapplication. A summation of the above for a 3-6-year-old child yielded an estimated nondietary total dose of 208 microg/kg/day. Potential exposure from the inhalation pathway was negligible, while dermal and nondietary oral doses from playing with toys contributed to 39 and 61% of the total dose, respectively. If children with high frequency mouthing behavior are considered as candidates for acute exposure to chlorpyrifos residues, the estimated acute dose could be as high as 356 microg/kg/day. Routine reapplication of pesticides could lead to continued accumulation in toys and other sorbant surfaces, e.g., pillows, with large sorbant reservoirs, which can become a long-term source of exposure to a child. Estimates of a child's nondietary exposure to chlorpyrifos associated with toys and other sorbant surfaces for a period of 1 week following application appear to be of public health concern, and studies of actual childhood exposure from this pathway are warranted in the home environment. The above information should be used to determine if current procedures for postapplication reentry are sufficient and to evaluate the need for procedures to store frequently used household toys, pillows, and other sorbant objects during insecticidal application.ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6

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Agricultural activity on Prince Edward Island poses a potential hazard to groundwater, which is the sole source of drinking water on the island. This study investigates the potential impact of groundwater nitrate exposure on prematurity and intrauterine growth restriction on Prince Edward Island. A total of 210 intrauterine growth restriction cases, 336 premature births, and 4098 controls were abstracted from a database of all Island births. An ecological measure of groundwater nitrate level was used to gauge potential exposure to agriculturally contaminated drinking water. The higher nitrate exposure categories were positively associated with intrauterine growth restriction and prematurity, and significant dose-response trends were seen, even after adjustment for several important covariates. Nevertheless, these risks must be interpreted cautiously because of the ecological nature of this exposure metric. An investigation using nitrate levels for individual study subjects is needed to confirm this association.