title: Analysis of mercury in rock varnish samples in areas impacted by coal-fired power plants.
abstract: Rock varnish is a manganese-iron rich coating that forms on rocks, most often in arid climates. To assess its utility as an environmental monitor of mercury contamination, cold vapor atomic absorption spectrometry (CVAAS) was used for analysis. Samples were collected in the fallout patterns of two coal-fired power plants in southern Nevada: the defunct Mohave Power Plant (MPP) and the operating Reid Gardner Power Plant (RGPP). The resultant Hg concentrations in rock varnishes were plotted as a function of the distance from each power plant. The highest concentrations of Hg occurred at locations that suggest the power plants are the main source of pollutants. In addition, past tracer plume studies carried out at MPP show that the highest tracer concentrations coincide with the highest rock varnish Hg concentrations. However, additional samples are required to further demonstrate that power plants are indeed the sources of mercury in varnishes.
authors.affiliation: Clark County Department of Air Quality, 4701 W Russell Road, Suite 200, Las Vegas, NV 89118, USA. nowinski@clarkcountynv.gov
authors.forename: Piotr
authors.initials: P
authors.lastname: Nowinski
authors.forename: Vernon F
authors.initials: VF
authors.lastname: Hodge
authors.forename: Shawn
authors.initials: S
authors.lastname: Gerstenberger
authors.forename: James V
authors.initials: JV
authors.lastname: Cizdziel
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data; D003031:Coal; D004784:Environmental Monitoring; D008628:Mercury / Q000032:analysis*; D009505:Nevada; D011210:Power Plants; D018570:Risk Assessment
chemical_list: D000393:Air Pollutants; D003031:Coal; D008628:Mercury