Arsenic and lead exposure in vietnamese gold mining communities: A case study of metabolic enzyme impacts

This study assesses seasonal heavy-metal contamination from gold mining in the Bong Mieu River basin (central Viet Nam) and examines its association with human xenobiotic-metabolizing enzyme phenotypes. In sediments, As and Pb consistently exceeded Vietnamese sediment quality limits, by 4.1-25.4 × for As and 2.3-7.8 × for Pb, whereas other metals generally remained within regulatory thresholds. River water exhibited widespread Pb exceedances at all sites and occasional. As exceedances, with higher concentrations in the dry season. Regression analyses indicated strong water-sediment coupling for As, Pb, Hg, Cd, and Zn, supporting shared transport and accumulation processes. Season-resolved Pearson correlations, HCA, PCA, and APCS-MLR source apportionment revealed a dominant mining-derived multi-metal signal year-round, intensified and spatially mixed under monsoon hydrology. Enzyme phenotypes varied with the mixed-metal exposure gradient: sites with higher As/Pb burdens showed higher frequencies of slow NAT2 and intermediate/slow CYP450 phenotypes, and longer residence was associated with higher NAT2 rapid-phenotype frequency.