Chapter 15 Gaseous selenium and other elements in Near-Surface atmospheric samples, Southeast Idaho

Abstract Concentrations of selenium (Se) and other selected elements were determined in air samples taken near the Unit 4 waste-rock pile of the Wooley Valley phosphate mine in southeastern Idaho. The waste-rock pile is approximately 3 million m 3 (4 million yard 3 ) in volume. Twenty-four-hour air samples were taken in June 2000 at two locations down- stream from the waste-rock pile along Angus Creek in Little Long Valley and 48-h air sam- ples were taken in May 2001 at two locations near the toe of the waste-rock pile. The purpose of the study was to determine if Se and other environmentally significant volatile elements that are present in the waste-rock pile are also present in the nearby atmosphere. Three of the sampling sites were in wetland areas near the toe of the waste-rock pile through which drainage travels. The wetland is a candidate source for the release of volatile trace elements including Se from the soil and/or plants. The results indicate that small but measurable elevations of Se concentration (30–90 ngm 3 ) occur in the near-ground atmosphere at the wetland compared to a nearby background location. No other trace ele- ments had elevated concentrations in the atmosphere at the wetland site.