R4 AM Occurrence and Fate of Pharmaceutical and Other Emerging Wastewater Contaminants in Aquatic Systems
Thursday, 17 November 2005: 8:00 AM - 11:40 AM in Ballroom 4

(BEN-1117-831465) Pharmaceuticals as tracers of municipal wastewaters in urban estuaries.

Benotti, Mark¹, Brownawell, Bruce¹, ¹ Stony Brook University, Stony Brook, NY, USA

ABSTRACT- The widespread distribution of many pharmaceuticals in wastewater effluents and receiving waters attests to their relative persistence. Attributes that might make this class of compounds powerful tracers of wastewater influence include their resistance to microbial transformation, lack of natural background signals, typically high water solubilities and low tendencies to be volatilized or removed by suspended particles. Wastewater tracers may be useful to better understand physical mixing of waters as well as trace the sources of other chemical and microbial contaminants in receiving waters. Here, we present data on the distributions of a broad suite of high-volume pharmaceuticals Jamaica Bay, a sewage-impacted estuary in New York City. As municipal wastewater is known to be the primary source of freshwater to the Bay, pharmaceutical concentrations should vary in a linear fashion with salinity if they behave conservatively and effluent concentrations are constant over the timescales on the order of the 2-4 week residence time in the Bay. For several pharmaceuticals, a linear relationship between concentration and salinity was observed, and extrapolations of such relationships were consistent with measured concentrations from one of the major sewage treatment plants that discharges to the Bay. The apparently conservative behavior of selected pharmaceuticals was also consistent with slow transformation observed in die-away studies conducted with water from NY Harbor. With the analytical methods employed, pharmaceutical tracers can be detected at 0.1% of wastewater effluent concentrations with caffeine and paraxanthine being the potential tracers with greatest signals relative to method detection limits. Much lower concentrations of pharmaceuticals could be measured if more selective compound-specific selective methods of extraction and isolation are employed.

Key words: HPLC-MS, pharmaceuticals, wastewater