Risk assessment of applicators to chlorpyrifos through dermal contact and inhalation at different maize plant heights in China.

Dermal and respiratory exposure assessments and risk assessment for applicators were performed with 48% chlorpyrifos EC. The chlorpyrifos was applied with lever-operated knapsacks under three spraying environments, namely, average maize field heights of 62 cm (A1), 108 cm (A2), and 212 cm (A3). The whole body dosimetry technique was applied to collect dermal exposure samples including cotton protective garments, gloves, socks, and hats. A personal air monitor equipped with an XAD-2 resin was used for respiratory exposure assessment. Without personal protective equipment (PPE) the total potential dermal exposure (PDE) was 27.8, 90.6, and 462.1 mL h(-1) under A1, A2, and A3 spraying environments, respectively. In addition, with the change in the maize plant height, the major exposure parts on the applicators were also different. Under single-layer garment and glove protection circumstances, internal dermal exposure (IDE) was 3.37 mL h(-1) for A1, 4.28 mL h(-1) for A2, and 18.32 mL h(-1) for A3. Potential inhalation exposure (PIE) was detected in A3, but it was not detected in A1 and A2. For risk assessment, the margin of safety (MOS) was calculated from the PDE or IDE and PIE. The MOS values for the three spraying environments were <1 under no PPE and single-layer garment and glove protection circumstances, indicating high possibility of health risk. However, with double protective garments, the MOS values for A1 and A2 cases were all >1, but the MOS was <1 in the A3 case.