ASSESSMENT OF POTENTIAL EXPOSURE TO LEGACY AND EMERGENT CONTAMINANTS THROUGH A KARST AQUIFER

Puerto Rico has the highest rate of preterm birth in United States. Preliminary investigations suggest that the increase in preterm birth rates in Puerto Rico cannot be explained by changes in known factors, and there is sufficient evidence that exposure to legacy and emergent contaminants may contribute to preterm birth. Contamination in Puerto Rico is extensive with over 150 polluted sites impacting water resources and posing threats to the environment and public health. Of particular concern is the contamination in the north-coast karst aquifer. This aquifer provides important freshwater resources for human consumption and ecologic integrity. The same characteristics that make karst aquifers highly productive make them highly vulnerable to contamination and impart an enormous capacity to store and convey contaminants from sources to potential exposures zones. As a result, there is an inherent risk of exposure to contamination thorough groundwater. This research develops a systematic methodology to: assess the extent of groundwater contamination in the karst aquifer of northern Puerto Rico; relate contamination to drinking water and other modes of exposure; and assess the presence of contaminants in a human pregnancy cohort. The study focused on chlorinated volatile organic compounds (CVOCs) and phthalates because of their ubiquitous presence in the environment and potential for exposure and health impacts. Results show an extensive historical contamination of the groundwater resources in the northern karst aquifers that has reached drinking water sources. Preliminary epidemiologic studies reveal the presence of contaminant exposure biomarkers in human subjects. Future work will evaluate the potential relationships between exposure to contaminants and preterm birth.