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Temporal and spatial behavior of pharmaceuticals in Narragansett Bay, Rhode Island, United States.
Cantwell, M., D. Katz, J. Sullivan, K. Ho, AND R. Burgess. Temporal and spatial behavior of pharmaceuticals in Narragansett Bay, Rhode Island, United States. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, 36(7):1846-1855, (2017).
Little is known about the behavior, fate and effects of pharmaceutical compounds in urban estuarine systems. Estuaries are often receiving waters for domestic wastewater treatment plant (WWTP) effluents, many of which service large cities and high density population areas. This study focused on the spatial and temporal variability of fifteen high volume use active pharmaceutical ingredients (APIs) within an urban estuary over a one year period. Findings indicate that the majority of pharmaceuticals measured reside primarily in the dissolved fraction and are likely still bioactive and bioavailable. Continuous influx from WWTPs and urban rivers containing effluents resulted in sustained concentrations of APIs at elevated levels, creating a zone of “pseudo-persistence” and continuous exposure. As a result, some of the pharmaceutical compounds in the Providence River are exceeding experimentally derived effects thresholds at times during this study. Work is continuing in order to improve our understanding of the fate of pharmaceuticals at larger spatial and temporal scales.
The behavior and fate of pharmaceutical ingredients in coastal marine ecosystems are not well understood. To address this, the spatial and temporal distribution of 15 high-volume pharmaceuticals were measured over a 1-yr period in Narragansett Bay (RI, USA) to elucidate factors and processes regulating their concentration and distribution. Dissolved concentrations ranged from below detection to 313 ng/L, with 4 pharmaceuticals present at all sites and sampling periods. Eight pharmaceuticals were present in suspended particulate material, ranging in concentration from below detection to 44 ng/g. Partitioning coefficients were determined for some pharmaceuticals, with their range and variability remaining relatively constant throughout the study. Normalization to organic carbon content provided no benefit, indicating other factors played a greater role in regulating partitioning behavior. Within the upper bay, the continuous influx of wastewater treatment plant effluents resulted in sustained, elevated levels of pharmaceuticals. A pharmaceutical concentration gradient was apparent from this zone to the mouth of the bay. For most of the pharmaceuticals, there was a strong relationship with salinity, indicating conservative behavior within the estuary. Short flushing times in Narragansett Bay coupled with pharmaceuticals’ presence overwhelmingly in the dissolved phase indicate that most pharmaceuticals will be diluted and transported out of the estuary, with only trace amounts of several compounds sequestered in sediments. The present study identifies factors controlling the temporal and spatial dynamics of dissolved and particulate pharmaceuticals; their partitioning behavior provides an increased understanding of their fate, including bioavailability in an urban estuary. Environ Toxicol Chem 2017;36:1846–1855. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.