Spatially Detailed Survey on Pollution by Multiple Perfluorinated Compounds in the Tokyo Bay Basin of Japan

Abstract

Pollution from 35 perfluorinated compounds (PFCs) in the water of the Tokyo Bay basin was examined. The water in the basin contained relatively high levels of perfluorononanoate (PFNA), perfluorooctanoate (PFOA), and perfluorooctane sulfonate (PFOS) compared to the other PFCs, which were present at concentrations of 20.1 ng/L, 6.7 ng/L, and 5.8 ng/L, respectively. In contrast, the concentrations of their precursors and degradation products were an order of magnitude lower. Sewage treatment plant (STP) effluent in the area also contained high levels of PFNA compared with the river water samples (Mann-Whitney U-test, p<0.0002). From a spatial aspect, increases in PFC pollution levels correlated with increased urbanization in the study area suggested that there are nonpoint source contributors to the PFC pollution in this area. Branched isomers of the PFCs were also quantified. Samples that contained high concentrations of perfluoroalkyl carboxylates (PFCA) showed lower proportions of its branched isomer. This indicates that the branched isomers are more prominent in the area with lower PFC pollution. This analysis was beneficial for estimating the individual contributions of different PFCA production processes. This survey provided new information on the sources, spatial distribution, and behavioral characteristics of PFC pollutants in this area.

Survey of perfluoroalkyl acids (PFAAs) and their precursors present in Japanese consumer products

“…A previous study suggested that PFNA in Japanese rivers was potentially derived from consumer products made in Japan (Murakami et al, 2008). It was also reported that PFNA was the most predominant compound among PFASs investigated in rivers in the Tokyo Bay basin (Zushi et al, 2011). This coincided with our study and suggests that PFNA was used in large amounts in consumer products and might be a substitute for PFOA in Japan.…”

“…The concentrations of detected PFCA precursors ranged from <LOQ-24 ± 14 ng g À1 for 8:2 FTCA and <LOQ-17 ± 13 ng g À1 for 10:2 FTCA (Table S2). In a previous study, FTCAs and FTUCAs were also detected at low concentrations (<0.09 ng g À1 ) in rivers in the Tokyo Bay basin (Zushi et al, 2011). These FTCAs and FTUCAs may be impurities generated during manufacturing, since their concentrations are too low for them to have served as intentional ingredients.…”

“…2b). These products can potentially cause continuous pollution by releasing PFOS into the environment as discussed in a previous study (Zushi et al, 2011).…”

“…The low detection frequency and low concentration level of PFOS observed in this study suggest that regulations regarding PFOS have effectively contributed to the reduction of PFOS in consumer products. However, a previous study found that PFOS regulations did not effectively decreased PFOS pollution in rivers in the Tokyo Bay basin between 2005 and 2009 (Zushi et al, 2011). Based on this result, PFOS detected in river water may have originated not only from current consumer products, but also from stockpiles such as AFFFs equipped in car parks, houses, etc., and formation from its precursors.…”

Perfluoroalkyl and polyfluoroalkyl substances: current and future perspectives

“…[18,31] Modelling studies have also shown that WWTPs are the predominant sources of PFASs in the aquatic environment, [32] although diffuse non-point sources of pollution exist in urban areas. [33] Land application of sewage sludge is another pathway of PFASs to the food chain. Studies have shown that current wastewater treatment processes do not adequately remove PFASs present in the waste stream.…”