Exposure and Human Health Risk Assessment of Pharmaceutical in Drinking Water

This thesis investigates the concentration of human pharmaceuticals in US drinking water by conducting human health risk assessment for 35 pharmaceuticals, belonging to 17 drug classes, for which the US environmental monitoring data is accessible. Using the measured environmental concentrations (MECs) in surface water from the U.S. Geological Survey (USGS) dataset and related papers, human exposure was assessed by calculating acceptable daily intakes (ADIs) for each one of the 35 pharmaceuticals. Calculated ADIs, which are an indication of potential exposure, are then compared to reference ADIs. Reference ADI values exist to protect the general population, as well as the sensitive subgroups of general population, likely to be exposed to human pharmaceuticals through two indirect exposure pathways: drinking water and fish. Predicted no effect concentrations (PNECs) for children and adults are then calculated using potential exposure values and compared to MECs. Both the ratios of potential exposure to reference exposure as well as the ratios of MECs to PNECs were very low. For all 35 compounds, these two low ratios show that there is no considerable human health risk from the presence of trace amounts of these pharmaceuticals in US drinking water and fish.