Levels of perfluorooctane sulfonate and perfluorooctanoic acid in female serum samples from Japan in 2008, Korea in 1994-2008 and Vietnam in 2007-2008.

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have recently received attention owing to their widespread contamination in the environment. One of major manufacturers, 3M Company voluntarily phased out PFOS production in 2002. We measured the PFOS and PFOA concentrations in serum samples from Japan (Sendai, Takayama and Osaka), Korea (Busan and Seoul) and Vietnam (Hanoi) to evaluate the possible effects of the phase-out on the serum levels. There were spatial differences in both the serum PFOS and PFOA concentrations. The serum PFOS concentrations (ngmL(-1)) evaluated as the geometric mean (geometric standard deviation) in 2007-2008 ranged from 4.86 (1.45) in Sendai, Japan, to 9.36 (1.42) in Busan, Korea. The serum PFOA concentrations ranged from 0.575 (2.32) in Hanoi, Vietnam, to 14.2 (1.73) in Osaka, Japan. Historically archived samples collected from Korea in 1994-2008 revealed that the serum PFOA concentrations increased by 1.24-fold in Busan from 2000 to 2008 and 1.41-fold in Seoul from 1994 to 2007. On the other hand, the serum PFOS concentrations did not change from 1994 to 2007/2008. The serum PFOS levels in Japan in 2008 were significantly decreased compared with previously reported values (22.3-66.7% of the values in 2003/2004). However, the serum PFOA levels showed a clear decline from 2003 to 2008 in a high-exposed area, Osaka, but not in low-exposed areas in Japan. The trends toward decreases were not uniformly observed in Asian countries, unlike the case for the United States, suggesting that local factors associated with the production and introduction histories in each country overwhelm the effects of the phase-out.

The influence of time, sex and geographic factors on levels of perfluorooctane sulfonate and perfluorooctanoate in human serum over the last 25 years.

Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) are important perfluorochemicals (PFCs) in various applications. Recently, it has been shown that these chemicals are widespread in the environment, wildlife and humans. But the kinds of factors that affect their levels in serum are unclear, and it is also not clear whether exposure to them is increasing or not. To investigate the impacts of time, geographical location and sex on the levels of these chemicals, we measured PFOS and PFOA concentrations in human sera samples collected both historically and recently in Miyagi, Akita and Kyoto Prefectures in Japan. The PFOS and PFOA levels in sera [Geometric Mean (Geometric Standard Deviation)] (microg/L) in 2003 ranged from 3.5 (2.9) in Miyagi to 28.1 (1.5) in Kyoto for PFOS and from 2.8 (1.5) to 12.4 (1.4) for PFOA. Historical samples collected from females demonstrated that PFOS and PFOA concentrations have increased by factors of 3 and 14, respectively, over the past 25 yr. There are large sex differences in PFOS and PFOA concentrations in serum at all locations. Furthermore, there are predominant regional differences for both PFOS and PFOA concentrations. In Kyoto the concentrations of PFOA in dwellers who had lived in the Kinki area for more than 2 yr were significantly higher than in people who had recently moved into the area, in both sexes. This finding suggests that there are sources of PFOA in the Kinki area that have raised the PFOA serum levels of its inhabitants. Further studies are needed to elucidate these sources in the Kinki area of Japan.