Oil Spills Can Lead to Toxic Arsenic Water Contamination, Study Says

When petroleum breaks down in underground aquifers, toxic arsenic — up to 23 times the current drinking water
Water sampling at the Minnesota oil-spill test site.
standard — can be released into groundwater, according to a study by U.S. Geological Survey and Virginia Tech researchers, who analyzed samples collected over 32 years from a petroleum-spill research site in Minnesota. Arsenic, a toxin and carcinogen linked to numerous forms of cancer, is naturally present in most soils and sediments, but is not typically a health concern because its chemical properties keep it bound within soil and minerals. However, certain chemical reactions associated with petroleum contamination and microbial activity in low-oxygen environments, such as in aquifers, change the chemical state of the arsenic so that it can enter the groundwater, researchers say.