Clarifying Behavior of Prallethrin Evaporated from an Electric Vaporizer on the Floor and Estimating Associated Dermal Exposure

The behavior of prallethrin evaporated from an electric vaporizer was investigated through three experiments to determine: 1) distribution of residue levels on the floor, 2) floor levels during prolonged daily evaporation and 3) amount of residue transferable from the floor. Results of the third experiment suggest a regular decrease of transfer efficiency denoted by the function of time (t)−0.5. From the measured values, dermal exposure was estimated for Japanese sub-groups using a new methodology based on the US EPA procedure, taking into account periodic application, a body-specific transfer factor, the transition rate through clothes, and the ratio of bodily deposition to floor deposition. © Pesticide Science Society of Japan