Bhuie A K, Ogunseitan O A, White R R, Sain M, Roy D N
Program in Industrial Ecology, Department of Environmental Health, Science, and Policy, School of Social Ecology, University of California, Irvine, CA 92697-7070, USA.
Sci Total Environ. 2005 Mar 1;339(1-3):167-78. doi: 10.1016/j.scitotenv.2004.06.012.
The environmental impacts of gasoline additives such as lead (Pb) and Methyl Tertiary Butyl Ether (MTBE) are well documented, leading to the phasing out of these additives. In contrast, little is known about the health and environmental impacts of potential replacement chemicals such as Methylcyclopentadienyl Manganese Tricarbonyl (MMT). The combustion of MMT in gasoline leads to the formation of MnPO4 and MnSO4 and MMT is considered a recent source of inorganic Mn in urban landscapes particularly in high traffic areas. The main objective of this study is to estimate the automotive deposition of Mn from MMT relative to the traffic volume at sites near a major highway in the Greater Toronto Area of Canada, where MMT is currently being used. Manganese emission levels were estimated for two sites that varied according to Annual Average Daily Traffic (AADT) density, fuel consumption, distance traveled by automobiles, and Mn concentration (mg l(-1)) in gasoline. Multiple regression analysis was used to predict the AADT volume from year 2002-2010. Comparison of the mass balance between the ANOVA means of 15% Mn emitted from the automobile tailpipes at 10, and 18 mg of Mn l(-1) in gasoline was conducted for both study sites. The percentage difference between the Mn input at the selected concentrations of Mn in gasoline and output into surface soil were found to be 99% significant for both sites. Thus the predicted 15% tailpipe emission levels for 10 mg of Mn l(-1) of gasoline used in automobiles, which represented 1290.03 g/year for site 1 and 555.94 g/year for site 2, will add 5.73 and 2.47 mg/kg of Mn annually, respectively. These input levels are considered negligible when compared to the natural abundance of Mn in soil. Based on these data, it could take more than 95-256 years of continuous MMT usage in the region to double the content of Mn in surface soils at the respective sites.
汽油添加剂如铅（Pb）和甲基叔丁基醚（MTBE）对环境的影响已有充分记录，这导致了这些添加剂的逐步淘汰。相比之下，对于潜在替代化学品如甲基环戊二烯基三羰基锰（MMT）对健康和环境的影响却知之甚少。MMT在汽油中的燃烧会导致磷酸锰（MnPO4）和硫酸锰（MnSO4）的形成，并且MMT被认为是城市环境中无机锰的一个新来源，尤其是在交通繁忙的地区。本研究的主要目的是估计在加拿大大多伦多地区一条主要高速公路附近使用MMT的地点，相对于交通流量，MMT中锰的汽车沉积量。根据年平均日交通量（AADT）密度、燃料消耗、汽车行驶距离以及汽油中锰的浓度（mg l(-1)），对两个地点的锰排放水平进行了估计。使用多元回归分析预测了2002 - 2010年的AADT量。对两个研究地点汽车尾气排放的15%锰（以10 mg的锰l(-1)计）与汽油中18 mg的锰l(-1)的方差分析均值之间的质量平衡进行了比较。发现在所选汽油锰浓度下锰的输入量与进入表层土壤的输出量之间的百分比差异在两个地点均具有99%的显著性。因此，对于汽车使用的10 mg的锰l(-1)汽油，预测的15%尾气排放水平，对于地点1为每年1290.03 g，对于地点2为每年555.94 g，将分别每年增加5.73和2.47 mg/kg的锰。与土壤中锰的自然丰度相比，这些输入水平被认为可以忽略不计。基于这些数据，该地区持续使用MMT超过95 - 256年，才能使各地点表层土壤中的锰含量翻倍。
