Phthalates are widely used in many consumer products; DEHP is the most frequently used plasticizer in the market. Their extensive use results in spatially-widespread sources that are difficult to identify. Their presence in groundwater is related to land use patterns and is influenced by hydrogeologic characteristics. Phthalate contamination is important to evaluate in eogenetic karst aquifers because they are an important source of freshwater for human consumption and ecological integrity, but also facilitate flow of pollutants into the groundwater. Karst aquifers, such as those found in northern Puerto Rico, are highly susceptible to contamination and a potential source of exposure. Prior research from PROTECT has shown that pregnant women in Puerto Rico are exposed to higher levels of phthalates when compared to pregnant women in the US mainland.

PROTECT evaluated the occurrence of phthalates in the karst aquifer system of northern Puerto Rico, the spatial distribution patterns of their concentrations, and the hydrogeological and anthropogenic factors affecting the spatial presence and concentrations. Spatial and statistical analysis of data collected from historical records and field samples conducted by PROTECT show that phthalates are present in the karst aquifers of northern Puerto Rico at low concentrations, with DEHP, DEP, and DBP being the most prevalent phthalates. They are also spatially distributed in the study area, showing a widespread contamination from multiple sources. Phthalate concentrations increase through time, reflecting continuous sources of phthalates entering the aquifer system. Statistical models show that the same hydrogeological factors that make these aquifers highly productive also play an important role in predicting the detection of phthalates in karst aquifers of eogenetic character. As a result, those aquifers pose high risk of exposure to phthalate contamination.

For more information on this study, refer to our recent publication.