| Organic contaminants of emerging concern (CECs) can have adverse affects in aquatic systems. They are difficult and expensive to quantify because of low aquatic concentrations- making monitoring and risk assessment challenging. Low-density polyethylene (PE) has shown promise as an in-situ passive sampler for quantifying CECs in aquatic systems. PE/water partitioning coefficients (KPEWs) for were measured for the following contaminants: components of fire retardants brominated diphenyl ether PBDE 47 and TBPH; DDT metabolites p,p'-DDMU and p,p'-DDNU; current-use pesticide methoprene; and polychlorinated biphenyl (PCB) legacy contaminants PCB 8, PCB 101, and PCB 209 were determined in a spiked sea water laboratory calibration experiment.;KPEWs were successfully determined for several organic contaminants: PCB 8, PCB 101, DDMU, and PBDE 47. The measured KPEWs correlated very well with octanol-water partitioning coefficients and fit previously published log KPEW log KOW plots: logKPEW = 0.92logKOW + 0.22, R2 = 0.90. KPEWs used for measuring dissolved water concentrations in the field were determined by fitting published KOW values to this equation.;Once partitioning coefficients had been determined PE passive samplers were deployed multiple sites and depths to assess their fate and transport away from wastewater treatment outfalls in Santa Monica Bay and Los Angeles Harbor. A deployment matrix was designed to give insight on the fate, transport, and point source of contamination for each of the targeted compounds. Measurements were corrected for non-equilibrium conditions using performance reference compounds, where necessary, and were compared to concentrations in caged mussels co-deployed with the PE samplers.;Dissolved water concentrations of 25 DDT metabolites, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were measured in the field study. Depth profiles of the DDT metabolites and PCBs in Santa Monica Bay suggested that the contaminants originated from historical contamination in the sediment. Both compound classes were found well dispersed throughout Los Angeles Harbor water column. PBDE spatial trends showed no clear evidence that contamination is currently coming from the WWTPs in both bodies of water. Concentrations were two to three times higher in near Hyperion WWTP outfall compared to concentrations near Terminal Island WWTP.;Mussel tissue uptake mimicked measured dissolved water concentrations-supporting PE as a viable passive sampling device. Measured bioconcentration factors differed for each target compound. The measured bioconcentration factors linearly correlated to the log KPEWs (an R2 of 0.83, rho<0.001 was observed) suggesting that PE is a good indicator of mussel bioconcentration in the water column. |
