Which coastal and marine environmental contaminants are truly emerging?

To better understand the past and present impact of contaminants of emerging concern (CECs) in coastal and marine ecosystems, archived samples were analyzed for a broad suite of analytes, including pharmaceuticals and personal care products (PPCPs), flame retardants (including PBDEs), perfluorinated compounds (PFCs), and current-use pesticides. Surface sediment, mussels (Mytilus spp.) and sediment core samples collected from the California (USA) coast were obtained from environmental specimen banks. Selected CECs were detected in recent surface sediments, with nonylphenol (4-NP), its mono- and di-ethoxylates (NP1EO and NP2EO), triclocarban, and pyrethroid insecticides in the greatest abundance. Alkylphenols, triclocarban, and triclosan were present in sediment core segments from the 1970s, as well as in Mytilus tissue collected during the 1990s. Increasing concentrations of some CECs (e.g., miconazole, triclosan) were observed in the surface layers (ca. 2007) of a sediment core, in contrast to peak concentrations of 4-NP and triclocarban corresponding to input during the 1970s, and an apparent peak input for PBDEs during the 1990s. These results suggest that chemicals sometimes referred to as "emerging" (e.g., alkylphenols, triclocarban) have been present in the aquatic environment for several decades and are decreasing in concentration, whereas others (e.g., miconazole, triclosan) are increasing.

Occurrence of DDA in DDT-contaminated sediments of the Southern California Bight.

DDT, DDE and some additional lipophilic derivatives are recognized contaminants in sediments of Southern California Bight (SCB). Only about 10% of total DDTs discharged into the SCB are accounted for using available monitoring data (sediment, water, and biota). DDA represented up to 0.03% DDTs (DDT/DDE/DDD) in SCB surface sediments (top 2 cm) in amounts up to 76 µg DDA/kg dry weight. Highest DDA levels were found where DDT and DDD levels were maximal at the primary wastewater outfall indicating a natural precursor-product relationship for DDT and DDA. Still culture of SCB sediment revealed limited DDA formation following DDT fortification. DDA residues have also been found in contaminated Long Island, NY sediments provided by USGS. The formation of DDA and its potential release from sediments may be significant in resolution of uncertainties concerning the natural recovery of sediments in DDT-contaminated environments.