報告書番号

V08047

タイトル（和文）

微量物質の健康リスクに関する文献調査（その2）

タイトル（英文）

Literature survey on health risk of trace substances

概要 （図表や脚注は「報告書全文」に掲載しております）

電気事業の環境リスク対策では疫学や生物研究に基づく健康リスク情報の把握とそれに基づくリスク評価が重要であるため、火力発電所から排出されるPRTR法対象22微量物質について最新の健康リスク情報を調査し、有害性の有無と強さ及び毒性閾値を整理した。吸入曝露での発がん性は22物質中12物質、非発がん毒性は17物質に認められた。経口曝露での発がん性は13物質、非発がん毒性は19物質に認められた。有害性の強弱は曝露経路によらず類似しており、発がん性はベンゾ[a]ピレン、クロム、ベリリウム、ニッケル、ヒ素、カドミウムが強く、非発がん毒性は水銀、ヒ素、クロム、カドミウム、ベリリウム、ニッケルが強かった。正確なリスク評価のためには実際の排出物質の化学形態で評価する必要性が示唆された。今後は発電所から排出される微量物質を対象に、最新の有害性情報と曝露量評価に基づいた健康リスク評価を実施する必要がある。

概要 （英文）

The aim of this literature survey was to gather the latest health risk information of 22 trace chemical substances emitted from thermal power plants. The information includes strengths of hazard and toxicity thresholds. These substances were acetaldehyde, arsenic (As), benzene, benzo[a]pyrene (BaP), boron (B), beryllium (Be), cadmium (Cd), cobalt (Co), chromium (Cr), fluoride (F), formaldehyde, hydrochloric acid (HCl), mercury (Hg), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), vanadium (V), and Zinc (Zn). They were designated chemicals by the Pollutant Release and Transfer Register (PRTR) law of Japan. The survey revealed that 12 chemical substances had carcinogenic potency, and 17 ones showed non-carcinogenic toxicity by inhalation exposure. Thirteen among 22 substances were carcinogenic, and 19 of these bore non-carcinogenic toxicity to human when they were orally exposed. Inhalation unit risk (UR, a measure of carcinogenic potency) and inhalation reference concentration (RfC, a measure of non-carcinogenic toxicity) of these substances were summarized. Oral slop factor (SF, a measure of carcinogenic potency) and oral reference dose (RfD, a measure of non-carcinogenic toxicity) were summarized together. By definition, larger inhalation UR and larger oral SF, as well as smaller inhalation RfC and smaller oral RfD indicate greater hazard to human. Because the RfC and RfD were derived from toxicity thresholds in original epidemiological and toxicological studies, these threshold values were also surveyed and tabulated. Substances with relatively greater carcinogenicity among the 22 of those were BaP, Cr, Be, Ni, As, and Cd. Substances with greater non-carcinogenic toxicity were Hg, As, Cr, Cd, Be, and Ni. Obtained results indicate that the hazards of chemical substances differ not so much by the route of exposure, but substantially depending on their chemical forms. Accordingly, for the accurate health risk assessment, the forms of chemical substances for risk characterizations should be matched with the forms of those in the actual emissions from thermal power plants.

報告者

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