Hexavalent chromium review, part 1: Health effects, regulations, and analysis

First of a two-part review summarizing the current state of the science regarding hexavalent chromium, this article addresses health effects, regulations, and analysis; part 2 will cover occurrence, chemistry, and treatment. Although hexavalent chromium—Cr(VI)—is a known human carcinogen when inhaled, its effects when taken orally (e.g., consumed in drinking water) are still being evaluated. The outcome of the ongoing US Environmental Protection Agency toxicologic review will determine whether a new federal maximum contaminant level will be set specifically for Cr(VI). In California, a public health goal of 0.02 μg/L has been established, and the state is proceeding to set a maximum contaminant level for hexavalent chromium. Analytical methods for hexavalent chromium can reliably quantify Cr(VI) at sub-parts-per-billion levels, whereas methods for measuring total chromium are much less sensitive. A new US Environmental Protection Agency method is available for Cr(VI) analysis, with updated requirements for chromium speciation preservation, holding time, and filtration.