Exposure assessment of operators to clothianidin when using knapsack electric sprayers in greenhouses

China is ranked first by greenhouse area in the world; pesticide application using knapsack electric sprayers is the main tool used in these settings to prevent and control plant diseases and insect pests. This is the first report of an exposure assessment for 60 greenhouse operators to the insecticide clothianidin when applied with knapsack electric sprayers. The commercial clothianidin formulation used in the field trials was a 20% suspension concentrate. The assessment was based on the whole-body dosimetry method and a personal air sampler fitted with an XAD-2 resin tube located in the operator’s breathing zone to monitor dermal and inhalation exposure, respectively. During application, the total dermal unit exposure was 598.71 mg/kg. The leg was the largest exposure area, accounting for about 53% of total dermal exposure. Meanwhile, inhalation exposure was only 0.50 mg/kg. The margin of exposure was much greater than 100 in all cases, indicating that the risk is controllable with the use of protection equipment and comparable to that of the manual application of treated soil.