Human Risk from Exposure to Heavy Metals and Arsenic in Water from Rivers with Mining Influence in the Central Andes of Peru

Water pollution by heavy metals is one of the leading environmental concerns as a result of intense anthropogenic pressure on the aquatic environment. This constitutes a significant limitation to the human right of access to drinking water. In this context, the risk to humans from exposure to heavy metals and arsenic in water from rivers subject to mining influence in the Central Andes of Peru was assessed. Water samples were collected from seven rivers at 63 sampling sites, and concentrations of Cu, Fe, Pb, Zn, and As were determined using flame atomic absorption spectrophotometry. Cluster analysis was used to group 21 sampling sites into four groups with similar chemical characteristics, and principal component analysis was used to simplify the complex relationship between the toxic elements by generating two main components with a total percentage of variation of 86%. Fe, Zn, and As had higher percentages of contribution in the Mantaro, Cunas, and Chia rivers. The hazard quotient was highest for children and adults. The hazard index for ingestion of all the studied heavy metals and As was higher than the threshold value (HIing > 1). HIing in 43% of the rivers indicated that the adult population is at risk of non-carcinogenic effects, and HIing in 14% of the rivers revealed a very high health risk. The risk of cancer by ingestion for children varied from medium to high risk and for adults from low to high risk.