Figure 1 Structures of perfluoroalkane sulfonates

Perfluorooctane sulfonate (PFOS) and related perfluorinated compounds (e.g. PFHS, PFBS, PFOA) have received world wide attention during the last three years. This class of chemicals is also being referred to as "PCBs of the twenty first century". The strength of the carbon-fluorine bond contributes to the stability of the fluorochemicals¹⁾. These compounds repel water and oil, reduce surface tension. The products containing PFOS and related compounds have been used in a wide variety of applications such as coatings for textiles, papers, packaging, fire-fighting foams, herbicides and pesticides¹⁾. PFOS is an end product of the biological metabolism of various sulfonated fluorochemicals²⁾. PFOS has been identified in human sera and in wildlife^3)~6). These chemicals are considered as emerging persistent organic pollutants (POPs), but compared with chlorinated and brominated organic compounds, the environmental distribution of perfluorinated compounds (PFCs) is poorly understood. To understand the spatial distribution of PFCs, exposures concentrations were measured in a various parts of the world.

Japan is one of the major industrialized nations in the world and prior to this investigation occurrence of PFCs in environmental media in Japan was not known. In 2000, the first national project on PFOS and related compounds was started at AIST under the support of New Energy and Industrial Technology Development Organization (NEDO). An international study between AIST, Japan and Michigan State University, US was established and the first survey was made to estimate PFOS in the blood of Japanese humans, which showed the presence of measurable level in 2001. In this study, we report results of the first environmental survey of PFOS and related compounds in some environmental samples (fish, surface water and human) collected from Japan.

Blood and Liver of bird, fish, surface seawater and human blood were analyzed in this study. Forty four blood and eleven liver samples of fish and thirteen surface sea water samples were analyzed and these were collected from Tokyo Bay, Osaka Bay, Lake Biwa, Seto Inland Sea, Ariake Bay, and Okinawa in Japan (Figure 3) during March-June, 2002. Human blood and sera were collected from Japanese citizens (n=3, age: 25~36) in June, 2002. Extraction procedures for blood, liver and water are presented elsewhere¹⁵⁾.

• PFOS was found in blood and livers of all fishes and surface water from Japan.
• Concentrations of PFOS in blood of fishes ranged from 2 to 834 ng/mL, and in the order of

• The greatest concentration PFOS in surface water was found in Tokyo Bay at 59 ng/L, and in the order of

• PFHS was detected in some fishes and surface water samples.
• The greatest concentration of PFHS was found 121ng/mL in blood of flat fish from Tokyo Bay.
• PFBS was not found in any samples.

Figure 3 Spatial distribution of PFOS in fish [ng/mL] and surface water [ng/L] from Japan.

Comparison PFOS with the other pollutants in Japan

• Concentrations of PFOS in blood of fishes were comparable to those of PCBs and 10,000 times higher than those of PCDDs and PCDFs.
• Concentrations of PFOS in surface water were similar to those of PAH and much more higher than those of PCBs, PCDDs and PCDFs.
• PFOS concentrations in blood of fishes were approximately 10 times higher than those in Japanese human blood.

Comparison Japan with US

• Concentrations of PFOS in Japanese fishes were similar to those in some fishes from the Great Lakes region of the US.
• Concentrations of PFOS in surface water of Tokyo Bay were similar to those reported for the Tennessee River in the US.
• PFOS concentrations in Japanese sera were similar to American.

Figure 4 Concentrations of perfluoroalkane sulfonates and the other pollutants in Japan and US 3),4),7)~10).

Bioconcentration Factor (BCF) of PFOS in fish

• Log BCF of PFOS ranged from 3.1 to 4.3 in Tokyo Bay.
• BCF of PFOS was similar to those of PCDDs and PCDFs.
• BCF of PFOS in Tokyo Bay was similar to or less than those in Etobocoke Creek, a contaminated area in the Canada.

Figure 5 Bioconcentration Factor (BCF) of PFOS and the other pollutants 11)~14).

These results provide the first evidence of occurrence of PFOS in fishes, surface water and human blood in Japan and that the concentrations are comparable to those in the US. Of the three perfluoroalkane sulfonates monitored, PFOS was the most predominant fluorochemicals in the tissues analyzed. The situation of PFOS pollution in Japan supposes to be similar to those of PCBs or PAHs. Quantitative bioaccumulation of PFOS in fish from surface water was made clear in this study. Considering the necessity to perform comprehensive survey of PFOS and related compounds to understand the mechanisms of human exposure and environmental fate of PFOS in Japan, the second national research project "Development of comprehensive risk database for PFOS related compounds" will start in 2003 by AIST(EMTECH) and NIAH supported by Ministry of Environment.
 

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Nobuyoshi Yamashita
AIST, Institute for Environmental Management Technology(EMTECH)