Bioavailability of arsenic and lead in soils from the Butte, Montana, mining district

Abstract

Risk assessments for mining sites are typically based on As and Pb bioavailability determined from studies using soluble metal salts. This is an inappropriate analogue of soil ingestion at mining sites due to the lower solubility of As and Pb in naturally occurring mineral assemblages. As and Pb bioavailability in soils from Butte, MT, is further reduced by authigenesis, where galena oxidizes to form a coating of anglesite further armored by sparingly soluble K-jarosite precipitates. Enargite and tennantite were also encapsulated by K-jarosite