Zayed Joseph, Guessous Anass, Lambert Jean, Carrier Gaétan, Philippe Suzanne
TOXHUM (Human Toxicology Research Group), Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, Qc, Canada, H3C 3J7.
Sci Total Environ. 2003 Aug 1;312(1-3):147-54. doi: 10.1016/S0048-9697(03)00224-9.
Methylcyclopentadienyl manganese tricarbonyl (MMT), is an organic derivative of Mn used as an anti-knock agent in Canadian unleaded gasoline since 1976. This study aims to estimate Mn emissions from MMT source in the Canadian environment as well as the Mn pollution index per capita in each of the Canadian provinces. In concomitance, lead emissions will also be addressed. The quantities of Mn and Pb used in gasoline were calculated from data on annual gasoline sales in Canada supplied by Statistics Canada. Obviously, the Pb emission profile shows a substantial decrease with an annual average of -28% until 1991, when MMT totally replaced Pb in Canadian gasoline. The case of Mn is quite different. Since emission rates of Mn at the tailpipe vary between 6 and 45%, the quantities released into the atmosphere were calculated for each of these rates, as well as for 100 and 25% emission rate scenarios. For 1981 and 1999, the quantities of Mn used in gasoline were estimated at 101122 and 344880 kg, respectively. Based on the realistic 25% emission rate scenario and a concentration of 0.009 g/l of Mn in gasoline, Mn emissions from car exhausts were estimated to 25280 and 86220 kg, respectively. The mean annual increase in emission rate between 1981 and 1999 is 7.34%. The atmospheric Mn pollution index seems to be stable over time, and it varies from 0.0024 kg/capita to 0.0041 kg/capita in 1999. In the context of a notable decrease in Mn emissions from industrial sources, these results suggest that the combustion of MMT used in gasoline may be an important factor contributing to maintaining stable atmospheric Mn concentrations instead of a significant decrease due to reduced industrial emissions.
甲基环戊二烯基三羰基锰（MMT）是锰的一种有机衍生物，自1976年以来在加拿大无铅汽油中用作抗爆剂。本研究旨在估算加拿大环境中MMT源的锰排放量以及加拿大各省的人均锰污染指数。同时，也将探讨铅排放量。汽油中锰和铅的使用量是根据加拿大统计局提供的加拿大年度汽油销售数据计算得出的。显然，铅排放情况呈现出大幅下降，到1991年年均下降28%，此时MMT在加拿大汽油中完全取代了铅。锰的情况则大不相同。由于排气管中锰的排放率在6%至45%之间变化，针对这些排放率以及100%和25%排放率的情景分别计算了排放到大气中的量。对于1981年和1999年，汽油中使用的锰量估计分别为101122千克和344880千克。基于实际的25%排放率情景以及汽油中锰的浓度为0.009克/升，汽车尾气中的锰排放量估计分别为25280千克和86220千克。1981年至1999年排放率的年均增长率为7.34%。大气锰污染指数似乎随时间保持稳定，1999年人均从0.0024千克到0.0041千克不等。在工业源锰排放显著下降的背景下，这些结果表明汽油中使用的MMT燃烧可能是维持大气锰浓度稳定的一个重要因素，而不是因工业排放减少而大幅下降。
