Abstract
In 2002, Daikin Industries’ Yodogawa Plant (DIYP) in Settsu City in Japan had contaminated drinking water in Hanshin area with perfluorooctanoic acid (PFOA), leading to the complete cessation of PFOA production in 2012. In 2023, local residents conducted a voluntary Blood Monitoring Campaign with 1,182 general residents. Blood monitoring was also conducted for former or current workers from DIYP and farming residents in Settsu City. Serum PFOA concentrations determined by gas chromatography with mass spectrometry [number: ng/mL: median (25th–75th percentile)] were as follows: former and current workers [N=7: 192.6 (23.3–596.6)] > farming residents [N=5: 70.2 (50.4–98.8] > general residents [N=1,182: 5.0 (3.3–7.0) ] with significant differences (Kruskal-Wallis test, p<0.001). In a study, 4 out of 5 farming residents showed a serum PFOA decline (half-life: 2.2 yr, 95% CI: 1.4–4.6) after stopping local agricultural product consumption. However, 3 former workers exhibited no decrease over 0.8–0.9 yr. An investigation found that 5 of the 7 subjects were likely exposed to dust from the polymerization of tetrafluoroethylene or handling its particulate matters, with 3 showing Interstitial Lung Disease (ILD) signs. This suggests PFOA-laden dust may delay excretion and contribute to ILD, though the mechanistic link remains unclear, requiring further research.
