(1)金沢市市街地の大気中1,3-,1,6-,1,8-ジニトロピレン(DNP)及び1-ニトロピレン(1-NP)の平均濃度は,それぞれfmol m^<-3>,サブpmol m^<-3>〜pmol m^<-3>レベルであった.これらの化合物濃度は,日中に高く夜間から早朝に低い日内変動を示し,交通量と高い相関が認められたことより,主要発生源は自動車と推定された.また,これらの化合物濃度は春から夏に低く,秋から冬に高い季節変動を示し,その要因の一つとして,前者には太陽光による光分解が,後者には逆転層による大気の安定が考えられた. (2)ガソリン車とディーゼル車の排ガス中DNP,1-NP濃度及び粉じん量を比較すると,DNP濃度は大差ないが,後者は前者に比べて1-NP濃度が遙かに高く,粉じん量も多い.これらに基づいて金沢市市街地の大気中DNP,1-NPについて発生源としてのディーゼル車の寄与率を求めると,それぞれ約90%,99%以上と試算された. (3)金沢市,東京都,札幌市の大気中DNP及び1-NP濃度には,都市の特徴によって多少の違いがあるものの,類似した日内及び季節変動が認められた.3都市の中では,札幌市がDNP濃度に対する1-NP濃度の比が最も大きく,その理由として,ガソリン車に対するディーゼル車の保有台数の割合が高いことが考えられた. (4)大気中1,3-,1,6-,1,8-DNP及び1-NP濃度推移と,Ames試験による大気直接変異原活性推移との相関は高く,上記化合物の大気直接変異原活性における寄与率は,YG1024株では約30%,TA98株では約10%と試算された.粒径別では,肺胞に沈積する割合の高い1.1μm以下の最微細粉じんに,化合物と変異原活性のいずれも最も多く分布していることが明らかとなった.大気変異原性に寄与するDNP,1-NP以外の化合物は,シリカゲルカラムクロマトグラフィーにより,DNPよりも低極性であると推定された.
(1) Each mean concentration of 1,3-dinitropyrene (1,3-DNP), 1,6-DNP,1,8-DNP and 1-nitropyrene (1-NP) in air in downtown Kanazawa were in the levels of fmol m^<-3> and sub pmol m^<33>-pmol m^<-3>, respectively. The concentrations were high in the daytime and low in the midnight and early in the morning. This diurnal variation gave a good correlation to the traffic volume, suggesting automobiles were the main contributors. The concentrations were high in spring and summer and low in autumn and winter. As reasons for this, degradation by sunlight in the former seasons and low atmospheric mixing dephts in the latter seasons were considered.(2) Concentrations of 1,3-, 1,6-and 1,8-DNPs and 1-NP in air in winter and summer in downtown Kanazawa, Sapporo and Tokyo were determined. Although the mean concentrations in Kanazawa were lower than those in Tokyo and Sapporo, there were similar tendencies as described above. The 1-NP to DNPs ratio in Sapporo was the largest in the three cities, suggest ing the largest diesel-engine vehicles to gasoline-engine vehicles ratio.(3) Concentrations of 1,3-, 1,6-and 1,8-DNPs in diesel Particulate were at the same levels as those in gasoline particulate. However, the concentration of 1-NP in diesel particulate was much higher than that in gasoline particulate. Considering the amount of particulates emitted from diesel-engine much larger than that of gasoline-engine, the contribution of diesel-engine vehicles to the amount of the above compounds in urban air was much larger than that of gasoline-engine vehicles.(4) In both diurnal and seasonal variation studies, good correlation coefficients were observed between the four concentrations and direct-acting mutagenic activities by the Ames test using three stains, TA98, YG1021 and YG1024. In the three, the YG1024 gave the largest coefficient. The contributions of the four compounds to the activities of air in YG1024 and TA98 strains were about 30% and 10%, respectively. The silica gel column chromatography suggested that the other contributors were less polar. When particulates were separately collected into five fractions of different particulate sizes, both the compounds and the activity were mainly contained in the finest particulate fraction (less than 1.1um) which was most adsorbed in alveoli of the lung.
研究課題/領域番号:06672138, 研究期間(年度):1994–1995
出典：「ニトロアレーンの環境動態解析とその軽減に関する基礎研究」研究成果報告書 課題番号06672138(KAKEN：科学研究費助成事業データベース（国立情報学研究所）) 本文データは著者版報告書より作成