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Chapter 7
Status and Trends of Perfluoroalkyl Substances in Japan with Special Emphasis on the Tokyo Bay Basin Shigeki Masunaga*,1 and Yasuyuki Zushi2 1Faculty
of Environment and information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan 2Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba City 305-8569, Japan *E-mail:
[email protected] Existing information on the occurrence and distribution of perfluoroalkyl substances (PFASs) in the Tokyo Bay basin was reviewed and reconstructed to show their temporal trends. The monitoring of river water in the basin showed that levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) decreased during 2004−2013. The monitoring of homologue profiles of perfluoroalkyl acids (PFAAs) in Tama River water in 2009−2014 showed a significant change. In 2009, perfluorononanoic acid (PFNA) was identified as the most abundant PFAS, followed by PFOA and PFOS. While levels of these three acids decreased in 2009−2014, perfluorocarboxylic acids (PFCAs) with perfluoro carbon chains C6, C8 and C9, and perfluoroalkyl sulfonates (PFSAs) with carbon chains C6 and C8, were contributing equally to the total level of PFAAs in 2014. Analysis of a dated sediment core from the center of Tokyo Bay indicated that the input of C8-13 PFCAs to the bay increased in 1977−2005 while PFOS increased from the 1970s to around 1993 and decreased gradually thereafter. These results indicate that the gradual decrease of PFOS emissions
© 2016 American Chemical Society Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.
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in the basin started in the early 1990s, while the decrease of PFOA and PFNA emissions started slightly later, after 2006. Furthermore, a study on PFAA precursors in Tama River water showed that the total amount of potential precursors in PFAA equivalents was as much as 50% of the total PFAAs present in the same sample and was not negligibly small, suggesting a need for further studies on PFAA precursors.
Terminology The terminology and acronyms used in this article for perfluoroalkyl and polyfluoroalkyl substances are shown in Table 1. This list follows, in principle, the system proposed by Buck et al. (2011) (1). Not all of the terms covered by the list are used in this article.
Introduction Perfluoroalkyl acids (PFAAs) have been widely used since the 1950s in antifouling agents, water repellants, oil repellants, fire-fighting foam, and many other applications. The unique properties of PFAAs come from their perfluorinated carbon chain. However, the perfluorinated carbon chain has both the merit of chemical stability and the issue of long-term environmental persistence. Due to their extremely long environmental persistence, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), two of the most common PFAAs, have been found in humans and in various wildlife species even in remote areas (2–5). Public health concerns relating to PFAAs increased after their ubiquitous presence in the environment was reported. The world’s primary producer of PFOS, 3M Corp., decided to take action and announced the phaseout of PFOS and PFOS-related products in May 2000. The company ceased production of PFOS in 2002. After phasing out PFOS, 3M Corp. and other companies used shorter chain perfluoroalkyl sulfonic acids (PFSAs) and perfluoroalky carboxylic acids (PFCAs) in its place. Under the circumstances, invited by the US Environmental Protection Agency (USEPA), eight major companies in the perfluoroalkyl substance (PFAS) industry joined the PFOA Stewardship Program in 2006 and promised to reduce facility emissions of all forms of PFOA, precursor chemicals that can break down to PFOA, and related higher homologue chemicals, as well as product content levels of all of these chemicals, to 5% of 2000 levels by 2010. They also promised to eliminate these chemicals by 2015 (6). These actions by leading companies, however, caused the production of PFASs spread to Asian countries such as China.
158 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.
Table 1. List of perfluoroalkyl substances and their acronyms
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Perfluoroalkyl and polyfluoroalkyl substances: PFASs Perfluoroalkyl acids: PFAAs Perfluoroalkyl carboxylates: PFCAs Perfluorobutanoic acid: PFBA Perfluoropentanoic acid: PFPeA Perfluorohexanoic acid: PFHxA Perfluoroheptanoic acid: PFHpA Perfluorooctanoic acid: PFOA Perfluorononanoic acid: PFNA Perfluorodecanoic acid: PFDA Perfluoroundecanoic acid: PFUnDA Perfluorododecanoic acid: PFDoDA Perfluorotridecanoic acid: PFTrDA Perfluorotetradecanoic acid: PFTeDA Perfluoropentadecanoic acid: PFPeDA Perfluorohexadecanoic acid: PFHxDA Perfluoroheptadecanoic acid: PFHpDA Perfluorooctadecanoic acid: PFODA Perfluoroalkyl sulfonates: PFSAs Perfluorobutane sulfonate: PFBS Perfluorohexane sulfonate: PFHxS Perfluoroheptane sulfonate: PFHpS Perfluorooctane sulfonate: PFOS Perfluorodecane sulfonate: PFDS Perfluoroalkyl phosphonic acids: PFPAs Perfluorooctyl phosphonic acid: C8-PFPA Perfluoroalkane sulfonyl fluorides: PASFs Perfluorobutane sulfonyl fluoride: PFBSF Perfluorooctane sulfonyl fluoride: PFOSF Perfluoroalkane sulfonamide substances Perfluoroalkane sulfonamides: FASAs Perfluorooctane sulfonamide: PFOSA N-Methylperfluoro-1-octane sulfonamide: MeFOSA N-Ethyl perfluorooctane sulfonamide: EtFOSA Perfluoroalkane sulfonamidoethanols: FASEs Perfluorooctane sulfonamidoethanol: FOSE N-Methyl perfluorobutane sulfonamide ethanol: MeFBSE N-Methyl perfluorooctane sulfonamide ethanol: MeFOSE N-Ethyl perfluorooctane sulfonamide ethanol: EtFOSE Perfluoroalkane sulfonamide acetic acids: FASAAs 2-(Perfluorooctane sulfonamido) acetic acid: FOSAA 2-(N-Ethylperfluorooctane sulfonamido) acetic acid: EtFOSAA Polyfluoroalkyl phosphoric acid esters: PAPs 8:2 Fluorotelomer phosphate monoester: 8:2 monoPAP 8:2 Fluorotelomer phosphate diester: 8:2 diPAP Fluorotelomer substances Fluorotelomer alcohols: FTOHs 1H,1H,2H,2H-perfluorooctanol: 6:2 FTOH 1H,1H,2H2H-perfluorodecanol: 8:2 FTOH 1H,1H,2H,2H-perfluorododecanol: 10:2FTOH Continued on next page.
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Table 1. (Continued). List of perfluoroalkyl substances and their acronyms Perfluoroalkyl and polyfluoroalkyl substances: PFASs Unsaturated fluorotelomer alcohols: FTUOHs 8:2 Unsaturated fluorotelomer alcohol: 8:2 FTUOH Fluorotelomer carboxylic acids: FTCAs 2H,2H,3H,3H-pentadecafluorodecanoic acid: 7:3 FTCA 2H,2H-heptadecafluorodecanoic acid: 8:2 FTCA 2H,2H-nonadecafluorododecanoic acid: 10:2 FTCA Fluorotelomer unsaturated carboxylic acids: FTUCAs 2H-hexadecafluoro-2-decenoic acid: 8:2 FTUCA 2H-octadecafluoro-2-dodecenoic acid: 10:2 FTUCA
Due to their widespread occurrence and reported toxicity in experimental animal and epidemiological human studies (7), perfluorooctane sulfonic acid (PFOS) and its salts (which are the most widely used class of PFAAs), perfluorooctane sulfonyl fluoride (PFOSF) (which is an intermediate chemical used to produce PFOS), and other PFOS-based chemicals were added to the list of persistent organic pollutants (POPs) under Annex B (restriction of production and use) of the Stockholm Convention on Persistent Organic Pollutants in May 2009 (8). At the time that they were listed, these chemicals fulfilled certain important functions for which alternative chemicals were unavailable. Specific exemptions allowing manufacturers to produce the chemicals to fulfill these functions were therefore granted. The list of specific exemptions included photo masks in the semiconductor and liquid crystal display industries, metal plating, electric and electronic parts, insecticides for the control of the red imported fire ants and termites, chemically driven oil production, carpets, leather and apparel, textiles and upholstery, paper and packaging, coatings and coating additives, rubber, and plastics. However, discussion of the restriction of PFOA is still underway. At the meeting of the Persistent Organic Pollutants Review Committee (POPRC), in October 2015, the committee agreed that PFOA meets the screening criteria for POPs and decided to prepare a risk profile document on PFOA, its salts, and PFOA-related compounds. Following the international listing of PFOS and PFOSF as POPs, the Japanese government designated PFOS, its salts, and PFOSF as ‘Class I Specified Chemical Substances’ in April 2010 (9). Under ‘the Act on the Evaluation of Chemical Substances and Regulation of their Manufacture, etc. (Chemical Substance Control Law),’ (10) chemicals that are persistent, bioaccumulative and toxic to humans are classified as ‘Class I Specified Chemical Substances’ and their production, import, and use are strictly prohibited. Thirty-one classes of chemicals are currently listed as ‘Class I Specified Chemical Substances’. The use of PFOS and PFOSF is prohibited except in three special cases, namely the production of etching agents for semiconductors, the production of resists for semiconductors, and the production of commercial photographic film. These uses are allowed with strict emissions management. Although the use of PFOS and PFOSF was virtually stopped in Japan, large amounts of aqueous film-forming foam (AFFF) (firefighting fluid) containing PFOS and its salts are stocked all over the country. According to the government’s estimate, in March 2016 these 160 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.
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stocks contained about 17 metric tons (hereafter, t) of PFOS and its salts (11). As it is difficult to replace these substances quickly, they are allowed to be stocked in controlled circumstances. Zushi et al. (2016) (12) reexamined the estimation of AFFF stockpiles in Japan and found large gaps between countries. Under the ‘Chemical Substance Control Law’, PFCAs with a carbon chain length of C12−16 are designated as ‘Monitored Chemical Substances’. ‘Monitored Chemical Substances’ are persistent and bioaccumulative chemicals whose toxicity is not yet clear. The production, import, and uses of these chemicals are monitored annually. Companies dealing with these chemicals are therefore required to report this information to the government. In addition, the government has the right to order the relevant companies to carry out toxicity tests when the chemicals become an environmental concern. However, PFOA and its related chemicals are not listed as ‘Class I Specified’, ‘Monitored’, or ‘Priority Assessment’ chemical substances, and they can still be legally produced and used. As shown above, Japan has been developing a unique chemical substance control system since 1973, when it was the first developed nation to introduce the ‘Chemical Substance Control Law’ based on the persistence, bioaccumulation potential and toxicity of chemical substances. Japan has also carried out quite extensive environmental monitoring and management for many environmental pollutants, including PFAAs. However, compared to those of other countries, Japan’s environmental monitoring data and results have not been well publicized internationally because of the language barrier. Therefore, in this article, we present a summary of the status and trends of PFAAs in the Japanese environment from various perspectives. Production and Import of Perfluoroalkyl Acids in Japan The data available in Japan on the production and use of PFAAs is limited. Table 2 shows a summary of the data available from government documents on the production and import of PFAAs in Japan. Japan’s Ministry of Economy, Trade and Industry (METI) has been collecting data from companies on the production, import and use of Monitored Chemical Substances since 2001, and of all chemicals mentioned in the Chemical Substance Control Law (whose production and import come to more than 1 t y−1) since 2010. Table 2 shows that the sum of production and import of PFOA-NH4 was 363 t y−1 in 2007. In other years, the disclosed data for PFOA-NH4 shows only a rough estimate of production and import, namely 10−
