[Characteristics of VOCs Emissions from Pesticide Use Sources Based on Pesticide Dosage Forms Analysis： A Case Study of Beijing].

To analyze the emission characteristics of VOCs from pesticide use sources in Beijing, the distribution of commonly used pesticides and dosage forms in Beijing was obtained through on-site research, and the VOC content of pesticides in different dosage forms was examined using laboratory testing methods. The emission factors of pesticide VOCs for localized dosage forms in Beijing were established, an inventory of pesticide use source VOCs was compiled, and the spatial and temporal distribution characteristics of pesticide use source VOCs were analyzed. The results indicated that ① Pesticide dosage forms were the main factors affecting the emission of VOCs from pesticides, and when accounting for VOC emissions from pesticide sources, it is necessary to know the types of pesticides and active ingredients in the target area and obtain information on pesticide dosage forms simultaneously. ② The localized emission factors for different dosage forms of pesticides were, in descending order, emulsifiable concentrate （839 g·kg）, soluble concentrate （715 g·kg）, emulsion in water （659 g·kg）, micro-emulsion （371 g·kg）, suspension concentrate （121 g·kg）, wettable powder （34 g·kg）, water dispersible granule （30 g·kg）, and aqueous solution （17 g·kg）. ③ In 2020, pesticide use and VOC emissions from pesticide use sources in Beijing were 2 990 t and 757 t. Among them, pesticide use of fungicides was the largest, accounting for 54.3% of the total, but its VOC emissions only accounted for 6.5%. Insecticides accounted for 34.8% of the pesticide use, and their VOC emissions were 84.1%. Among the different crop types, fruit trees had higher emissions of VOCs, with mixed fruits being the highest, accounting for 48.1%. ④ In terms of spatial distribution, the areas with higher emissions of VOCs were the ecological conservation development area （70.5%） and the new urban development area （24.4%）, with the Pinggu district having the highest emissions of VOCs, followed by the Miyun district and the Fangshan district, which accounted for 30.7%, 11.8%, and 8.9% of the total, respectively. Crops that contributed more to the ecological conservation development area were fruit trees, maize, potatoes, beans, etc.； crops that contributed more to the new urban development area were vegetables, wheat, and melons. In terms of time distribution, summer and spring were the peak periods for VOC emissions from pesticide use sources, accounting for 45.2% and 33.8% of the total, respectively.