Spatial and temporal trends in perfluorooctanoic and perfluorohexanoic acid in well, surface, and tap water around a fluoropolymer plant in Osaka, Japan.

This study was conducted to clarify the spatial distributions of perfluorooctanoic acid (PFOA) and perfluorohexanoic acid (PFHxA) in well, surface and tap water around a fluoropolymer plant in Osaka between 2003 and 2016 and to predict the fate of those chemicals in these aquatic environments. We analyzed 44 well, six surface and six tap water samples collected within a 5 km radius of the plant. The PFOA concentrations in well water ranged from 45.2 to 7440 ng/L (median = 240 ng/L), while PFHxA concentrations ranged from 9.68 to 970 (median = 45.4 ng/L) in 2015-2016. The concentration of other perfluoroalkyl carboxylic acids were lower than PFOA and PFHxA in well water. Fixed-point observation showed that the levels of PFOA decreased greatly over the last few decades, whereas those of PFHxA increased in both well and surface water. Further monitoring and investigation are suggested to understand PFOA and PFHxA contamination and fate in the environment, as well as their potential for human exposure in this region.