Heavy metal load, toxicity, and in vitro bioassay-based assessment of acid mine drainage water from a high-sulfur coal mining area

Abstract

Acid mine drainage (AMD), a serious global environmental problem that degrades water quality, causes severe ecological damage, and poses significant health hazards. In this study, AMD water samples from a high sulphur coalmine area were assessed and evaluated for human health and toxicological risks associated with contamination by potential heavy metals (HMs). The integrated study using correlation, principal component, and cluster analyses indicated that anthropogenic activities such as mining along with natural weathering processes, are the primary sources of HMs in the AMD water. Heavy metal toxicity load (HMTL) indicated significant removal of heavy metals from AMD mine water and discharge water, achieving compliance with potable water standards. The non-carcinogenic health hazard assessment indicates, adults are more vulnerable compared to children, with both carcinogenic and non-carcinogenic risks potentially present due to exposure to heavy metals. Cytotoxicity and in vitro assays using normal fibroblast L929 cells demonstrated nuclear morphological alterations and elevated intracellular reactive oxygen species (ROS) levels, indicating oxidative stress and cellular damage. The result highlights the urgent need for effective remediation strategies and continuous monitoring of AMD-impacted areas associated with high-sulfur coal mining, to protect both environmental and public health.