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Temporal and spatial behavior of pharmaceuticals in Narragansett Bay, Rhode Island, United States
Citation:
Cantwell, M., D. Katz, J. Sullivan, K. Ho, AND R. Burgess. Temporal and spatial behavior of pharmaceuticals in Narragansett Bay, Rhode Island, United States. Society of Environmental Toxicology and Chemistry (SETAC) North America 37th Annual Meeting, Orlando, FL, November 06 - 10, 2016.
Impact/Purpose:
Little is known about the behavior, fate and effects of pharmaceutical compounds in marine ecosystems. These systems are often receiving waters for domestic wastewater treatment effluents, many of which service large cities and high density, population areas. This study focuses on measuring the temporal variability of select pharmaceuticals in an urban estuary in the dissolved and particulate phase. Preliminary findings indicate that the majority of pharmaceuticals measured reside primarily in the dissolved fraction and are likely still bioactive and bioavailable.
Description:
The behavior of active pharmaceutical ingredients (APIs) in urban estuaries is not well understood. In this study, 15 high volume usage APIs were measured over a one year period throughout Narragansett Bay, RI, USA to determine factors controlling their concentration and distribution. Dissolved APIs ranged in concentration from not detected to 310 ng/L, with numerous APIs present at all sites and sampling periods. Eight APIs were present in suspended particulate material, ranging in concentration from <1 ng/g to 44 ng/g. Partitioning coefficients (Kds) were determined for APIs present in both the dissolved and particulate phases, with their range and variability remaining relatively constant during the study. Organic carbon normalization reduced the observed variability of several APIs to a small extent; however, other factors appear to play a role in controlling partitioning behavior. The continuous discharge of wastewater treatment plant effluents into upper Narragansett Bay resulted in sustained levels of APIs, resulting in a zone of “pseudo-persistence.” For most of the APIs, there was a strong relationship with salinity, indicating conservative behavior within the estuary. Short flushing times in Narragansett Bay coupled with APIs present primarily in the dissolved phase suggests that most APIs will be diluted and transported out of the estuary, with only small amounts of several compounds removed to and sequestered in sediments. This study identifies factors controlling the temporal and spatial dynamics of dissolved and particulate APIs, whose partitioning behaviors provide an increased understanding of their fate, including bioavailability, in an urban estuary.