METCALF, Rodney V.1, BAUMANN, Francine
2, BUCK, Brenda
3, YANG, Haining
4, REN, Minghua
5, MCLAURIN, Brett T.
6, GAUDINO, Giovanni
4, and CARBONE, Michele
4, (1) Department of Geoscience, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las Vegas, NV 89154-4010, rod.metcalf@unlv.edu, (2) University of Hawaii Cancer Center, 651 Ilalo Street, Suite BSB231, Honolulu, HI 96813, (3) Department of Geoscience, University of Nevada Las Vegas, 4505 South Maryland Parkway, Box 454010, Las Vegas, NV 89154-4010, (4) University of Hawaii Cancer Center, 651 Ilalo St, BSB Rm231, Honolulu, HI 96813, (5) Dept. Goesciences, UNLV, Las Vegas, NV 89154-4010, (6) Department of Environmental, Geographical and Geological Sciences, Bloomsburg University of Pennsylvania, 400 E. 2nd St, Bloomsburg, PA 17815
Population growth and expansion of urban areas in southern NV has increased roads, traffic, and the demand for recreational activities on public lands. This expansion has disturbed natural desert soils with increased dust emissions related to both natural wind and off-road-vehicle (ORV) activities (Goossens and Buck 2011). Malignant mesothelioma (MM) is a rare, fatal cancer linked to the inhalation of fibrous carcinogenic minerals. Preliminary analysis of data from the Nevada Cancer Registry finds MM in southern Nevada at abnormally high rates, low M:F gender ratios, and exceptionally young ages; the latter is of concern because of the typical 30-40 year latency period for MM. Such findings point to an environmental exposure to fibrous carcinogenic minerals via dust emissions. In response to these findings we have searched for possible environmental sources of fibrous carcinogenic minerals in proximity to urbanized areas.
Fibrous Na-amphiboles winchite and magneiso-riebeckite are recognized at three localities on nearby public lands (two in S. NV and one in adjacent AZ). The amphiboles are hydrothermal in origin and formed by Na-metasomatism in the faulted margins of Miocene plutons; erosion, transport and deposition in alluvial fans have increased the areal distribution of these materials. Some areas are scarred by ORV tracks and represent potential dust sources upwind of urban populations. SEM images document that that Na-amphibole fibers are <0.5 µm in diameter and 25 to 100 µm in length and exhibit parallel fibers bundles with splayed ends, matted masses of fibers and curved fibers capable of dust transport and human inhalation. The Na-amphiboles are similar in composition and habit to Na-amphiboles reported from the Libby vermiculite deposit (Meeker et al 2003) and implicated in MM cases at Libby, Montana.
Additional carcinogenic fibrous minerals in S. NV include a reported occurrence of erionite at the Nevada National Security Site (Chipera and Bish 1989) and palygorskite found in airborne dust in the Nellis Dunes Recreational Area 6 km northeast of Las Vegas (Buck et al., 2011).
Our future research looks to localize mesothelioma clusters, find the source(s) and carcinogenesis of fibrous minerals, potential pathways into human populations, and develop management strategies to reduce human exposure.
Geology and Health, Mineralogy/Crystallography
Preferred Presentation Type: Either Oral or Poster
