Identification of pollutant markers in rural mountainous areas of China by combining non-targeted analysis with zebrafish embryo toxicity tests.

Abstract

Emerging pollutants (EPs) are increasingly found around the world, yet their composition and the risks pose to soil environments remain unclear, making a challenge to EP management, particularly in mountainous rural areas. In this study, we collected soils from three types of mountainous villages, each representing different levels of economic development: an industrial village, an ecotourism village, and an agricultural village. We analyzed these samples using non-target analysis and Danio rerio embryotoxicity test (ZET). A total of 216 compounds (level 2) were identified by matching with mzCloud database, with 149, 107, and 157 found in YY (industrial village), DX (ecotourism village) and LH (agricultural village), respectively. Interestingly, 78 compounds were present in all three villages, while the number of unique substances ranged from 7 to 47 in each village, serving as potential pollution markers. The most prevalent substances identified were aliphatics, heterocyclics, and aromatics. The ZET results showed that all soil extracts had significant acute toxic effects. Further analysis revealed a correlation between the toxic substances and the economic types of the villages. Specifically, linear chain dicarboxylic acids, drugs, and oxygenated polycyclic aromatic hydrocarbons (OPAHs) were the primary toxicants in the industrial village, whereas phthalate esters dominated in the other two villages. These findings provide valuable insights for effective monitoring of EPs in mountainous rural areas.