Experimental refinement of dermal exposure for human health risk assessment of CHLOROTOLURON

摘要

Background: Chlorotoluron is a phenylureaherbicide. It is detected in surface and groundwatersall over the world. Although it has been evaluated for its dermal absorption during registration process, there is lack of available scientific data for calculating the risk that results from dermal exposure to this herbicide. Aims: The aim of this work was to measure the experimental dermal absorption of chlorotoluron andto calculate the permeability coefficient (Kp) and lag time (τ). These are used in many models as a value expressing the rate of dermal absorption. Human health risk assessment for dermal exposure in different scenarios has been done. Methods: Split-thickness abdominal pig skin was used, the dermalabsorption was measured using automatic system of static diffusion Franz cells (Microette, Hanson, infinite dose condition. The duration of the experiment was 24 hours so the steady-state flux (Jss) was achieved. Results: Jsswas achieved after 2,6 hours (lag time) of the experiment and it was equal to 0,0346 mg cm-2h-1. Experimental permeability coefficient (Kp) for chlorotoluronis 3.46 10-3 cm h-1. Conclusions: The Jss and Kp measured in this work are useful for risk assessors to evaluate the dermal risk of chlorotoluronin water. We used US EPA equation for calculating the dermal absorption of chlorotoluron from water in 6 different scenarios. The experimental values of dermal absorption kinetics are essential for accurate risk assessment. Dermal absorption values with a description of method used to generate them should be required during the registration process and accessible for the community of risk assessors.