Where's the dust? Characterizing locations of azinphos-methyl residues in house and vehicle dust among farmworkers with young children.

Organophosphate pesticides are commonly used in the United States, and farmworkers are at risk for chronic exposure. Using data from a community randomized trial to interrupt the take-home pathway of pesticide exposure, we examined the association between floor surface type (smooth floor, thin carpet, and thick carpet) and rooms in which dust samples were collected (living room vs. non-living room) and concentrations of azinphos-methyl residues in home environments. We also examined the association between vehicle type (truck, auto, or other) and footwell floor surfaces (carpeted, smooth surface, or no mat) and concentrations of azinphos-methyl in vehicle dust samples. Dust samples were collected from 203 and 179 households and vehicles, respectively. All households had at least one child aged 2-6. Vehicle dust samples were collected from footwells of the vehicle used for commuting to and from work. A total of 183 samples were collected from living rooms, and 20 were collected from other rooms in the home. Forty-two samples were collected from thick carpets, 130 from thin carpets, and 27 from smooth floor surfaces. Thick and thin carpets had a significantly greater dust mass than smooth floor surfaces (6.0 g/m(2) for thick carpets, 7.8 g/m(2) for thin carpets, and 1.5 g/m(2) for smooth surfaces). Of the 179 vehicle samples, 113 were from cars, 34 from trucks, and 32 from other vehicles. Vehicles with no mats had a significantly higher mass of dust (21.3 g) than those with hard mats (9.3 g) but did not differ from vehicles with plush mats (12.0 g). Further research is needed to characterize the environment in which children may be exposed to pesticides.