MEDICAL GEOLOGY RESEARCH AT THE UNIVERSITY OF TEXAS AT DALLAS: A DECADE OF CONTRIBUTIONS (Invited Presentation)

For over a decade Dr. Finkelman has been affiliated with The University of Texas at Dallas, and has contributed to many graduate research efforts. These divide neatly into two categories: human exposure via groundwater or atmospheric dust.

Groundwater exposure studies have focused on hazards from natural arsenic, and lignite-related hydrocarbons. Early studies explored natural groundwater arsenic contamination in the Ganges floodplain of Nepal. In these headwaters of the Asian Arsenic Crisis region, annual cycles in recharge (i.e. monsoonal flushing) yield inverse changes in dissolved arsenic in the thin shallow aquifers accessed by most tubewells in Nepal, reducing net risk, but making risk assessment and mitigation much more challenging. An ongoing study in Sri Lanka explores the strong spatial correlation between chronic kidney disease of unknown etiology and groundwater dependence in their "Dry Zone". Monthly monitoring of groundwater composition reveals cycling between rock-interaction and monsoonal recharge influences, but no clear inorganic hazard. Several studies have focused on the potential impacts of lignite-derived hydrocarbons in an important drinking water aquifer of Texas (the Carizo-Wilcox). Leaching studies established a clear link between the lignite and hydrocarbons found in groundwaters. Epidemiological studies established a strong correlation between the groundwater abundances of lignite-derived hydrocarbons and rates of end-stage renal disease and renal pelvis cancer in East and Central Texas.

Dust exposure research has explored the antrhopogenic hazard related to the mine dumps in Johannesburg, South Africa, and links between Saharan dust events and pediatric asthma in the Caribbean. In Johannesburg, reprocessing of gold mine ores using ultrafine milling has greatly increased the airborne abundance of PM2.5 dust, affected by seasonal storms. Residential encroachment on these tailings has magnified exposure to this hazard. Silicosis is the primary illness potentially affected by these changes, and silicosis rates have been increasing. In the Caribbean, detailed examination of Saharan dust events and pediatric asthma hospital admissions indicates a significant correlation in out-of-season events, but not necessarily with normal summer dust events.