Environ. Sci. Technol. 2005, 39, 859-866
Risk Assessment of Short-Chain Chlorinated Paraffins in Japan Based on the First Market Basket Study and Species Sensitivity Distributions F U K U Y A I I N O , * ,† T A K U M I T A K A S U G A , ‡ KURUNTHACHALAM SENTHILKUMAR,‡ NAOKI NAKAMURA,† AND JUNKO NAKANISHI† Risk Center for Chemical Risk Management, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan, and Shimadzu Techno-Research Inc., 1, Nishinokyo-Shimoaicho, Nakagyo-ku, Kyoto 604-8436, Japan
The chemical risks of short-chain chlorinated paraffins (SCCPs) to human health and ecological species in Japan were assessed in this study. SCCPs are used as extreme pressure additives in metal-working fluids and flame retardant agents in plastic materials. The first market basket study with a high resolution gas chromatography and mass spectrometry with electron capture negative ionization is reported. Total daily food intakes for Japanese residents of different ages were estimated using Latin Hypercube simulations, and the highest 95th percentile intake is 6.8 × 102 ng/kg/day for a 1-year-old child. Based on the reported no-observed-adverse-effect-level (NOAEL) and the estimated exposure mainly from food, it was concluded that SCCPs are not posing risks to humans in Japan. Ecological risks to aquatic and sediment organisms were estimated using species sensitivity distributions. The 95th percentiles of the distributions obtained by fitting several environmental SCCP concentration data of river water and sediment were 41.8 ng/L and 558 ng/g wet weight as the possible highest concentrations, respectively. No-observed-effectconcentrations (NOEC) were determined by calculating the fifth percentiles of a species sensitivity distribution, which were 2.2 µg/L for aquatic organisms and 1.7 to 13.5 mg/ kg wet weight for sediment organisms. While it is likely that there is no imminent environmental chemical risk for aquatic organisms at a regional level in Japan, this study concluded that a more detailed risk assessment is necessary for sediment organisms.
Introduction Polychlorinated n-alkanes (CnH2n+2-zClz; PCAs) or chlorinated paraffins (CPs) are industrial products manufactured by direct free radical chlorination of liquid n-paraffin or paraffin wax. * Corresponding author phone: +81-3-5467-1242; fax: +81-33406-7347; e-mail:
[email protected]. Current address: United Nations University, 5-53-70 Jingumae, Shibuya-ku, Tokyo 150-8925, Japan. † National Institute of Advanced Industrial Science and Technology. ‡ Shimadzu Techno-Research Inc. 10.1021/es049221l CCC: $30.25 Published on Web 01/05/2005
2005 American Chemical Society
Extreme pressure additives in metal-working fluids and flame retardant for plastic materials such as poly(vinyl chloride) are the main uses of PCAs (1). There are three groups of PCA compositions, for descriptive and regulatory convenience (2), which are short-chain (C10-13), medium-chain (C14-17), and long-chain compounds (longer than C18). The details of the chemistry and toxicology of chlorinated paraffins are well summarized in a recent complete review (3). The use of short-chain chlorinated paraffins (SCCPs) in metal-working and leather industries has been restricted since January 2004 in the European Union (EU) (4). SCCPs “may not be placed on the market for use as substances or as constituents of other substances or preparations in concentrations higher than 1% in metalworking or for fat liquoring of leather”. The decision was made based on the EU’s SCCP risk assessment conclusion that, in addition to a risk of secondary poisoning, a risk to aquatic organisms exists arising from (i) the local emission of SCCPs from the metal-working and leather finishing applications and (ii) the formulation of products for these uses. A predicted-no-effectconcentration (PNEC) for aquatic organisms in the EU assessment is 0.5 µg/L and was determined by dividing a no-observed-effect-concentration (NOEC) of 5 µg/L using Daphnia magna (1, 5) by an uncertainty factor of 10. At this concentration, no effect was observed for endpoints of survival, reproduction, nor growth. Two tiers of the U.S.’ risk assessment on chlorinated paraffins and olefins estimated that the most likely range of concern is 0.11 to 0.7 µg/L in water and listed the compounds on the toxics release inventory (TRI) with no further restriction (6, 7). Most environmental and food analytical data of SCCPs were measured by using thin-layer chromatography that could only detect chlorinated paraffins as two groups of C10-20 and C20-30 (8, 9). However, there are increasing demands on more specific monitoring data of SCCPs and Medium-Chain Chlorinated Paraffins or MCCPs (C14-17) due to the recent regulatory attentions given to the two groups of chlorinated paraffins (10, 11). SCCPs were also detected in marine mammals from the Arctic regions (3) using a high-resolution gas chromatography and mass spectrometry with electron capture negative ionization (HRGC/ECNI-HRMS). In Japan, SCCPs were largely used as substitute chemicals of polychlorinated biphenyls (PCBs) that have been banned in the 1970s. The annual production volume of SCCPs in Japan dropped to 500 tonnes in 2002 (10). The purposes of this study are to report on analytical results of some environmental and food samples in Japan and to assess human and ecological risks posed by SCCPs in Japan. We conducted environmental analysis of SCCPs to get a snapshot of the current environmental distributions in Japan. This paper reports the first market basket study on SCCPs. We studied SCCP concentrations of eleven food categories using HRGC/ECNI-HRMS. The measured concentrations in food products were used to calculate human total daily intake of SCCPs in Japan. In addition, ecological risk was assessed using the 95th percentile SCCPs concentrations of river water and sediment samples, to reinforce a lack of measurement, predicted from the measured concentrations.
Materials and Methods Environmental Samples. Four river water samples, three influent and three effluent samples from sewage treatment plants (STPs) in Tokyo, and six sediment samples from rivers were gathered for one time (see Table 1 for details). The river VOL. 39, NO. 3, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
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TABLE 1. Sampling Points and Samples of River Water, STP Influent and Effluent, and Sediment basic data sampling points no.
locations
1
Iwabuchi Suimon
2
Kasaibashi
3
Hirakata Ohashi
4
Yodogawa Ozeki
5 6 7 8 9 10
rivers 35°47′ N 139°44′ E 35°40′ N 139°50′ E 34°48′ N 135°38′ E 34°43′ N 135°30′ E
STP(A) influent STP(A) effluent STP(B) influent STP(B) effluent STP(C) influent STP(C) effluent
pH
Arakawa
conductivity, mS/cm
DO, mg/L
SS, mg/L
BOD, mg/L
0.359
6.0
10
5
