Baltimore Ecosystem Study Institute of Ecosystem Studies

2017 BES Annual Meeting Presentation and Poster Abstracts

Seasonal analysis of contaminants of emerging concern in the Gwynns Falls watershed
Blaney, Lee
Co-Authors: Ke He, Ethan Hain, Lee Blaney

Abstract: The objective of this work was to explore the presence of contaminants of emerging concern (CECs) in an urban watershed that is not impacted by upstream wastewater treatment plants or animal feeding operations. We conducted separate 10-week sampling campaigns in summer and winter 2016. Samples were analyzed for a large suite of CECs: 43 antibiotics from the fluoroquinolone, macrolide, sulfonamide, and tetracycline classes; 5 UV-filters, which are organic sunscreen agents; and, 3 estrogenic hormones. All CECs were quantified using solid-phase extraction liquid chromatography with tandem mass spectrometry. A number of antibiotics were frequently detected. For example, erythromycin and sulfamethoxazole were detected in 43% and 39%, respectively, of the winter samples. Several antibiotics, including clarithromycin, doxycycline, methacycline, ofloxacin, and roxithromycin, were detected at concentrations greater than 100 ng/L. At least two UV-filters were detected in every sample, and these CECs showed clear trends across the rural-to-urban flow gradient of the watershed. Estrone was the most frequently detected estrogenic hormone with concentrations in the 1-10 ng/L range. Although the synthetic hormone, 17α-ethinylestradiol, was not detected in water samples, we did detect it in select sediment and crayfish tissue samples from the sampling sites. In general, the occurrence and concentrations of CECs were higher for urban sites, highlighting human and ecological health concerns associated with these specialty chemicals. We hypothesize that the source of these diverse CECs may stem from leaking sewers and, therefore, CEC monitoring data may help inform efforts to improve and restore urban infrastructure.