Mining industry is a vital economic sector for many countries but it is also one of the most hazardous activities, both occupationally and environmentally. Existing studies point to several adverse effects on communities' health living near mines, effects such as mesothelioma and respiratory illnesses. Results achieved in a geochemical sampling campaign undertaken in the vicinity of São Francisco de Assis village showed an anomalous distribution of some heavy metals in soils and waters. To evaluate the effects of mining activities on human health produced by these conditions, a group of 28 individuals from São Francisco de Assis village was examined for some biological endpoints. A nonexposed group (30 individuals) with the same demographic characteristics without exposure to genotoxic compounds was also studied and data obtained from both groups compared. Results of the T-cell receptor mutation assay and micronucleus (MN) test showed significant increases in the frequencies of both mutations and MN in exposed subjects compared to controls. Data obtained in the analysis of the different lymphocyte subsets demonstrated significant decreases in percentages of CD3+ and CD4+ cells, and a significant increase in percentage of CD16/56+ cells, in exposed individuals. The results of the present study indicate an elevated risk of human environmental contamination resulting from mining activities, emphasizing the need to implement preventive measures, remediation, and rehabilitation plans. This would lead to a reduction in cancer risk not only for this particular population but for all populations exposed under similar conditions.