MP11 Advances in Bioaccumulation Assessment
Monday, 14 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(COO-1116-473148) Algal bioaccumulation of antimicrobials in a North Texas wastewater treatment plant (WWTP) receiving stream.

Coogan, M¹, Edziyie, R¹, La Point, T¹, Venables, B¹, ¹ University of North Texas, Denton, TX, USA

ABSTRACT- Algae comprise the greatest abundance of plant biomass in aquatic environments and are a logical choice for aquatic toxicological studies, yet have been underrepresented in this capacity. The lipid content of many algal species provides a point of entry for trophic transfer of lipophilic organic contaminants. Triclosan (TCS) and triclocarban (TCC), widely used antimicrobial agents found in numerous consumer products, are incompletely removed by WWTP processing. Methyl triclosan (M-TCS) is a metabolite of TCS more lipophilic than the parent compound. The focus of this study is to quantify bioaccumulation factors (BAFs) for TCS, M-TCS, and TCC in Pecan Creek, the receiving stream for the City of Denton, Texas WWTP. Filamentous algae (Cladophora spp.) and water column samples were collected from the WWTP outfall, an upstream site, and two downstream sites. Water samples were extracted with C18 solid phase extraction cartridges. Algae samples were Soxhlet extracted and a fraction containing the antimicrobial compounds was isolated by gel permeation chromatography. Final analysis of TCS and M-TCS was by selected ion monitoring using GC/MS. TCC was analyzed by negative-ion electrospray LC/MS. Antimicrobials in Pecan Creek water samples taken at and downstream from the WWTP are at low ppt concentrations of 10 - 200 ng/L and are elevated to low ppb concentrations of 1 - 200 ng/g fresh weight in algae collected from these stations. The resulting BAFs are approximately three orders of magnitude.

Key words: algae, antimicrobials, bioaccumulation