Characterization of Chemical Contamination in Shallow-Water Estuarine Habitats of an Industrialized River. Part 1: Organic Compounds

Abstract

The lower six miles of the tidal portion of the Passaic River (Study Area) has been heavily industrialized since the mid-1800s. The objectives of this study were to: quantify the present extent and magnitude of chemical contamination in surface sediments from the Study Area; evaluate the contamination in the Study Area relative to a reference area and surrounding regional waterways; assess the potential for adverse effects to aquatic organisms; and identify spatial gradients in concentrations that may indicate potential point-sources of chemicals. Because existing ecological communities center primarily on intertidal mudflats in the Study Area, composite surface sediment was collected from 15 mudflats to generate a realistic assessment of fish and wildlife exposure to sediment contaminants. This study showed that present concentrations of organic contaminants are elevated throughout the Study Area and are generally higher than concentrations in the reference area and regional waterways. A screening-level analysis showed that there is potential for adverse effects to sediment-associated organisms from a number of chemicals. No spatial trends were apparent for most compounds evaluated, consistent with the presence of multiple sources of chemicals in the Study Area. The exception is semivolatile compounds, which appear to be localized to specific mudflats, indicating potential point-sources of contamination for these chemicals.

Keywords:

• Sediment contamination
• dioxins
• pesticides
• PAHs
• PCBs
• Passaic River.

Notes

^a Pesticides, herbicides, and semivolatile compounds other than bis(2-Ethylhexyl)phthalate were typically at concentrations substantially below the sample quantitation limit (SQL). As such, a value of zero was assigned to non-detects to avoid artificially elevating the average and maximum concentrations of these compounds.

^b Total DDT calculated as the sum of p,p′-DDT, p,p′-DDE and p,p′-DDD.

^c Total PCBs calculated as the sum of homologues.

^d PCDD/F TEQs calculated based on the W.H.O. toxic equivalency factors (TEFs) (Van den Berg et al., 1998).

^a Pesticides, herbicides, and semivolatile compounds other than bis(2-Ethylhexyl)phthalate were typically detected at concentrations substantially below the sample quantitation limit (SQL). As such, a value of zero was assigned to non-detects to avoid artificially elevating the average and maximum concentrations of these compounds.

^b Total DDT calculated as the sum of p,p′-DDT, p,p′-DDE and p,p′-DDD.

^c Total PCBs calculated as the sum of homologues.

^d PCDD/F TEQs calculated based on the W.H.O. toxic equivalency factors (TEFs) (Van den Berg et al., 1998).

¹Only 38 PCB congeners were analyzed for this study. It is likely that additional congeners are present in this system based on the results of the Aroclor analyses and total PCB calculations that were performed.

^a Benchmark adjusted for Study Area average TOC content of 3.3%.

^a Does not include Passaic River data.

^b Value is total PCDD/F TEQ calculated based on the World Health Organization toxic equivalency factors (TEFs) (Van den Berg et al., 1998).