Insight into the effect of geographic location and intercropping on contamination characteristics and exposure risk of phthalate esters (PAEs) in tea plantation soils

Abstract

Phthalate esters (PAEs) are an emerging pollutant due to widespread distribution in environmental mediums that have attracted widespread attention over recent years. However, there is little information about tea plantation soil PAEs. A total of 270 soil samples collected from 45 tea plantations in the major high-quality tea-producing regions of Jiangsu, Zhejiang, and Anhui provinces in China were analyzed for seven PAEs. The detection frequency of PAEs in tea plantation soil was 100%. DBP, DEHP, and DiBP were the main congeners in tea plantation soil. The PAEs concentrations in the upper soil were significantly higher than those in the lower soil. The concentration of tea plantation soil PAEs in Jiangsu Province was significantly lower than those in Zhejiang and Anhui provinces. Intercropping with chestnuts can effectively reduce the contamination level of PAEs in tea plantation soil. Correlation analysis, redundancy analysis, partial correlation analysis, and structural equation modeling methods further confirmed the strong direct influence of factors such as chestnut–tea intercropping, temperature, and agricultural chemicals on the variation of PAEs in tea plantation soil. The health and ecological risk assessments indicated that non-carcinogenic risk was within a safe range and that there was a high carcinogenic risk via the dietary pathway, with DBP posing the highest ecological risk.

Keywords

• phthalate esters
• chestnut and tea intercropping
• driving factors
• spatial heterogeneity
• risk assessment