ACCUMULATION OF CHLORPYRIFOS ON RESIDENTIAL SURFACES AND TOYS ACCESSIBLE TO CHILDREN

Quantitative examination of major pathways and routes of exposure to p esticides is essential for determining human risk The current study wa s conducted in two apartments and examines the accumulation of the pes ticide chlorpyrifos in childrens' toys after the time suggested for re entry after application. It has been established for the first time th at a semivolatile pesticide will accumulate on and in toys and other s orbant surfaces in a home via a two-phase physical process that contin ues 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 20 8 mu g/kg/day. Potential exposure from the inhalation pathway was negl igible, 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 fo r acute exposure to chlorpyrifos residues, the estimated acute dose co uld be as high as 356 mu g/kg/day. Routine reapplication of pesticides could lead to continued accumulation in toys and other sorbant surfac es, e.g., pillows, with large sorbant reservoirs, which can become a l ongterm source of exposure to a child. Estimates of a child's nondieta ry exposure to chlorpyrifos associated with toys and other sorbant sur faces for a period of 1 week following application appear to be of pub lic 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 stor e frequently used household toys, pillows, and other sorbant objects d uring insecticidal application.