Mapping Risk from Mining Activities: A Case Study of Oruro, Bolivia

Author: Eugenia Naranjo
Organization: HydroQual

1 Lethbridge Plaza
Mahwah, NJ 07430
USA

Phone: 201-529-5151
Fax: 201-529-5728
enaranjo@hydroqual.com

Mining activities can cause significant environmental impacts in the form of increased metal concentrations in the air, groundwater, surface water, and soil. These concentrations present a potential risk to human health. A spatial risk assessment model was developed to estimate the risk of present and future mining activities.

The RISKMOD module developed by HydroQual is a screening-level tool that estimates the potential risk for residents and workers in and around mining areas from long-term exposure to concentrations of metals in environmental media. The model follows standard U.S. EPA human health risk computation methodology. Risk can be calculated for seven chemicals (e.g., cadmium, lead), nine pathways (e.g., swimming in surface water, outdoor air inhalation), four receptors (e.g., child resident, adult worker), and two scenarios (cancer effects and noncancer effects). In addition, a lead in soils exposure model is included for adult workers.

RISKMOD is different from conventional risk calculation models because risk can be calculated and presented spatially. For example, the risk to a child resident from inhalation of air containing arsenic is presented as contours of incremental excess lifetime cancer risk. The model output is an indication of the risk of adverse health effects due to long-term exposure to metals in the environment. Residents could therefore estimate their long-term exposure risk by locating their village or town on the risk contour maps. The module is part of the *MOD suite of environmental models developed by HydroQual. The *MOD extensions integrate GIS and environmental modeling technology. The models are integrated into the graphical user interface (GUI) of ArcView GIS.