R6 PM Bioavailability
Thursday, 17 November 2005: 1:50 PM - 5:30 PM in 324-326

(JEN-1118-273002) Metal bioavailability and potential toxicity in sediments adjacent to a former cable manufacturing facility.

Jenkins, K¹, Beardsley, K², Bartee, M³, Huntley, S¹, Kiehl-Simpson, C⁴, ¹ BBL, Inc., Petaluma, CA, USA² BBL, Inc., Walnut Creek, CA, USA³ BBL, Inc., Carpenteria, CA, USA⁴ Parsons Engineering Science, Inc., Williamsville, NY, USA

ABSTRACT- A study was conducted to evaluate site-specific bioavailabity and potential toxicity of metals in sediments adjacent to a former copper cable manufacturing facility on the Lower Hudson River. Due to the nature of historical operations, copper was the metal of primary interest. Surficial sediment samples were collected at 17 locations where previous sampling had demonstrated elevated concentrations of total metals. Bulk sediment samples were analyzed for total metals, redox potential, total organic carbon (TOC), acid volatile sulfides (AVS) and simultaneously extracted metals (SEM). Porewater was extracted and analyzed for total and dissolved metal concentrations, and dissolved organic carbon (DOC). Specific methods employed in this study are detailed in a separate presentation. Metals concentrations in bulk sediments were within the range of previously reported data. AVS concentrations were high and exceeded SEM concentrations of cadmium, copper, nickel, lead, and zinc at all locations (SEM-AVS ranged from -7.7 to -72.2) indicating that these metals should not be bioavailable or toxic to aquatic organisms. Concentrations of TOC in bulk sediments and DOC in porewater provide additional capacity to reduce metal bioavailabity and toxicity. Concentrations of metals in pore water were in the low ppb range. These data were compared against chronic marine ambient water quality criteria (AWQC). In addition, site-specific chronic marine AWQC for copper were developed based on DOC concentrations in porewater. Taken together these independent lines of evidence indicate that the concentrations of AVS in sediments and DOC in porewater are more than sufficient to limit metal bioavailability and prevent metal toxicity in these sediments.

Key words: acid volatile sulfides, metals, sediments, porewater