AIR DISPERSION MODELING
AERMOD Modeling System:
AERMOD is a steady-state plume model that incorporates air dispersion based on planetary boundary layer turbulence structure and scaling concepts, including treatment of both surface and elevated sources, and both simple and complex terrain. AERMOD has been used in investigations of dispersion of mercury emissions in Huancavelica, Peru and Potosí¬, Bolivia during colonial mining periods.
Mercury in Solids and Solutions by Thermal Decomposition, Amalgamation, and Atomic Absorption Spectrophotometry:
EPA Method 7473 was used to determine the total mercury concentration in soil samples taken from Huancavelica, Peru and PotosÃ¬, Bolivia in early summer 2009. This detection method is used for determining mercury concentrations in solids, aqueous samples, and digested solutions.
Field Portable X-Ray Fluorescence (FPXRF) Spectrometry for the Determination of Elemental Concentrations in Soil and Sediment:
EPA Method 6200 is used to determine screening level concentrations of toxic heavy metals in soil and can be used for efficient, cost-effective, and quick analysis. Because it is used for screening purposes, fixed lab analysis using other more accurate lab methods is recommended for a percentage of the FPXRF samples. In Huancavelica, heavy metals such as Hg, As, and Pb are often above the detection limit for FPXRF and thus this analysis method is excellent for quickly assessing the extent and magnitude of contaminant levels.
Exposure Factors Handbook 2011 (Final Report), USEPA
The exposures factor handbook is used to determine general exposure factors and supporting documentation for risk assessment. The datasets used for statistical derivation of specific exposure factors (ie body weight, ingestion rates, exposure durations) is based on large US population datasets. The document provides a good first set of exposure factors as well as much of the founding information that can be used for preliminary risk assessment calculations in international settings. However, more specific exposure factors specific to the population and lifestyle, may be appropriate.
Child-Specific Exposure Factors Handbook (Final Report) 2008, USEPA:
The Child-Specific Exposure Factors Handbook has been used to determine soil ingestion rates in children and to characterize hand-to-mouth activity. While this specific handbook is relevant to children in the United States, exposure circumstances for children in Peru and Bolivia are still very different than those for adults. This handbook can be used to understand the physiological and behavioral factors that are used to determine children’s exposure to environmental chemicals.
Graphical Arrays of Chemical-Specific Health Effect Reference Values for Inhalation Exposures (Final Report):
This document provides a graphical array and table of key information on the derivation of emergency response, occupational, and general public health effect reference values for a variety of chemicals. The information regarding inhalation reference values for elemental mercury was taken from this document for use in determining historical risk from exposure to mercury from mining operations during colonial times in Huancavelica, Peru and Potosí¬, Bolivia, in conjunction with AERMOD modeling estimations.
Integrated Risk Information System (IRIS) Toxicological Review of Elemental Mercury (1995):
The Toxicological Review of elemental mercury is a comprehensive review of chronic toxicity data completed by U.S. Environmental Protection Agency health scientists. The health assessment information includes a chronic inhalation reference concentration (RfC) value and a carcinogenicity assessment.
Mercury Study Report to Congress: http://www.epa.gov/mercury/report.htm
The Mercury Study Report to Congress, published in 1997, provides an assessment of U.S. mercury emissions by source, describes the health and environmental implications of emissions, and discusses the availability and cost of control technologies. This document provides valuable insight into the risks of exposure to mercury contamination in the environment for both humans and wildlife.
World Health Organization Guidelines on Mercury Exposure: www.who.int/mediacentre/factsheets/fs361/en/
The World Health Organization (WHO) has established health-related guidelines for protection of human health from exposure to mercury from a variety of sources. The following fact sheet provides an overview of mercury exposure in the world, different sources, acute and chronic effects, and what the WHO is doing in support of reducing people’s exposure.
Minimata Convention: www.mercuryconvention.org
The Minamata Convention which was established by the United Nations in 2013, is a global treaty to protect human health and the environment from the adverse effects of exposure to mercury. Twenty three nations have signed the treaty which establishes guidelines and milestones for reduction of each nation’s output of mercury through air emissions or other sources, creates controls on exposure to mercury from sources such as artisanal and small gold mining, and support cleanup of historical sources. Peru signed the treaty in January 2016.
EHC RELATED PUBLICATIONS
Amos, Helen; Sonke, Jeroen; Obrist, Daniel; Robins, Nicholas; Hagan, Nicole; Horowitz, Hannah; Mason, Robert; Witt, Melanie; Corbitt, Elizabeth; Sunderland, Elsie. “Global anthropogenic enrichment of mercury and implications for future environmental concentrations.” Environmental Science and Technology. Vol. 49, No. 7 (March, 2015), 4036–4047. DOI: 10.1021/es5058665
Estevan Sandoval, Miguel Yepez and Howell Howard. Peru Mercury Inventory, 2006. Washington, DC: United States Geological Service, 2007.
Hagan N, Robins N, Hsu-Kim H, Halabi S, Espinoza Gonzales RD, Ecos E, et al. “Mercury hair levels and factors that influence exposure for residents of Huancavelica, Peru.” Environmental Geochemistry and Health. Vol. 36, No. 6 (December, 2014). doi: 10.1007/s10653-014-9665-9
Hagan N, Robins N, Hsu-Kim H, Halabi S, Espinoza Gonzales RD, et al. (2013) “Residential Mercury Contamination in Adobe Brick Homes in Huancavelica, Peru.” PLoS ONE Vol. 8 No. 9. (September, 2013) doi:10.1371/journal.pone.0075179.
Hagan N, Robins N, Espinoza Gonzales RD, Hsu-Kim H. “Speciation and bioaccessibility of mercury in adobe bricks and dirt floors in Huancavelica, Peru.” Environmental Geochemistry and Health, Vol. 36, No. 4 (August, 2014). DOI 10.1007/s10653-014-9644-1
Robins N. Mercury, mining, and empire: The human and ecological costs of silver mining in the Andes. Indiana: Indiana University Press, 2011. Published in Spanish as Mercurio, Minerίa y Imperio: El costo humano y ecológico de la minerίa de plata colonial en los Andes (Huancavelica: Universidad Nacional de Huancavelica, 2011).
Robins, Nicholas and Nicole Hagan. “Mercury production and use in colonial Andean silver production: emissions and health implications.” Environmental Health Perspectives. Vol. 120, No. 5 (May, 2012): 627-631. doi: 10.1289/ehp.1104192.
Robins, N.A., N. Hagan, S. Halabi, H. Hsu-Kim, R.D. Espinoza Gonzales, M. Morris, G. Woodall, D. Richter, P. Heine, T. Zhang, A. Bacon, and J. Vandenberg. “Estimations of Historical Atmospheric Mercury Concentrations from Mercury Refining and Present-Day Soil Concentrations of Total Mercury in Huancavelica Peru.” Science of the Total Environment. Vol. 426, No. 11 (June, 2012):146-154. 2012. doi: 10.1016/j.scitotenv.2012.03.082
Thoms, Bryn and Nicholas Robins. “Remedial Investigation. Huancavelica Mercury Remediation Project. Huancavelica, Peru.” Unpublished Manuscript. March, 2015.