世界10カ国21都市の水環境におけるpfos・pfoa沘染の琭況

摘要

In this paper, we focus on perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in water environment of 21 cities in 10 countries (i.e., Japan, Singapore, Thailand, Malaysia, China, Vietnam, Taiwan, Sweden, Turkey and Canada). 1,160 samples were collected in different water environments (e.g., river, lake, wetland, reservoir, wastewater treatment plant, residence, and sea) from Nov. 2004 to Dec. 2007. The main conclusions obtained in this study are as follows: 1) The average concentration of PFOS in the surface water of rivers was more than 10.0 ng·l~(-1) in Osaka. The average concentration of PFOS in residential tap water was more than 10.0 ng·l~(-1) in Bangkok and Taipei. 2) The average concentration of PFOA in the surface water of rivers was more than 1,000 ng·l~(-1) (median : 48.6 ng·l~(-1)) in Osaka, and it was more than 15 ng·l~(-1) in Kyoto, Shenzhen, Khon Kaen, and Singapore. The average concentration of PFOA in residential tap water was more than 10 ng·l~(-1) in Osaka and Okayama in Japan. 3) The number of cities where the difference between river water and tap water was less than 1.0 ng·l~(-1) in the median concentrations of dissolved PFOS and PFOA was 16 for PFOS and 11 for PFOA, respectively. 4) The dissolved PFOS and PFOA concentrations in effluent were higher than those in influent of most wastewater treatment plants (16/19 for PFOS, 38/45 for PFOA).%テフロンでコーティングされた商品は世界中で使用さ れている。そのテフロンの製造に使われ，製品にも含まれ る化学物質ベルフルオロオクタン酸（以下PFOA）が，テフロ ン樹脂の加熱で外部に出る恐れがあると推測されている。 2005年6月，アメリカ環境保護局EPAの科学諮問委員会は， PFOAは「人間にとっておそらく発ガン性物質である（PFOA is a likely carcinogen in humans）」との毒性に関するリスク評 価案をまとめた。また，関連物質であるベルフルオロオク タンスルホン酸（以下PFOS）は難分解性，生物濃縮性，哺乳 類への毒性があり，ラットに対する2年間のPFOS曝露の結 果，肝細胞腺腫と甲状腺細胞の濾胞性膿瘍および血清蛋白 質への結合と内分泌かく乱作用が報告された。