Composition, Distribution, and Source Apportionment of Organochlorine Pesticides (OCPs) in Soil of a Chemical Industrial Park and its Surrounding in the Northeast of Qinghai-Tibet Plateau

Being the third polar region of the earth, the Qinghai-Tibet Plateau (QTP) has a significant impact on the whole earth, especially on the Eurasian environment and ecosystem, making it crucial to understand the environmental changes occurring in the area. However, the exploitation and utilization of mineral resources are affecting the ecosphere of QTP, especially in the farming-pastoral ecotone. More research needs to be conducted on the distribution and sources of persistent organic pollutants in this region. To address this research gap, this study investigates the characteristics of organochlorine pesticides (OCPs) in Ganhe industrial parks (GDIP), located in a farming-pastoral ecotone and the surrounding soils. The study analyzed 22 soil samples collected from two intersections. The findings revealed that hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) were the dominant components of the 15 OCPs, accounting for more than 75% of the total OCPs among sampling sites. These compounds had high mean concentrations of up to 2506.3 and 152.7 mu g kg(-1), respectively. High levels of OCPs were observed in the southeastern and southern regions of GDIP. Agricultural soils were more susceptible to OCP pollution due to frequent agricultural activities compared to grassland. Source apportionment analysis showed that OCPs in the area might primarily comprise lindane (detected in 54.5% of the samples) and dicofol (detected in 86.4% of the samples), implying that these two OCPs could still be in use in this area. Therefore, further investigation into the use and pollution of OCPs in the farming-pastoral ecotone in the northeast of QTP is necessary, and their impact on the ecosystem needs to be evaluated.