The Global Biogeochemical Cycle of Arsenic

Direct exploitation and use of arsenic resources has diminished in recent years, but inadvertent mobilizations of As from mineral extractions (metal ores, coal, and phosphate rock) are now as much as ten-fold greater (1,500-5,600 x 10(9) g/yr) than the As released by the natural rate of rock weathering at the Earth's surface (60-544 x 10(9) g/yr). Although some As from mining activities enters global cycling through leaching and spills, the amount of dissolved As in rivers (23 x 10(9) g/yr) is similar to the theoretical mobilization of As from chemical weathering. Anthropogenic emissions to the atmosphere (17-38 x 10(9) g As/yr) are double the natural background sources (10-25 x 10(9) g As/yr), largely as a result of the smelting of Cu and other non-ferrous ores. This results in increased atmospheric deposition near regions with high mining and industrial activities, with potential consequences to human health, natural ecosystems and agriculture. Using median values for As, the ratio of anthropogenic to natural emissions to the atmosphere (1.57) suggests a human impact on the global As cycle that rivals those for V, Hg and Pb.

Automated summary

The direct exploitation and use of arsenic resources has decreased in recent years, but unintentional releases of arsenic from mineral extractions are now ten times greater than the natural rate of rock weathering. Anthropogenic emissions of arsenic to the atmosphere, primarily from smelting activities, are double the natural background sources, leading to increased atmospheric deposition in regions with high mining and industrial activities, with potential consequences for human health, natural ecosystems, and agriculture.