Mehlman Myron A
Department of Environmental Medicine, The Mount Sinai Medical Center, New York, New York 10029, USA.
Ann N Y Acad Sci. 2002 Dec;982:149-59. doi: 10.1111/j.1749-6632.2002.tb04930.x.
Methyl tertiary butyl ether (MTBE) was added to gasoline on a nationwide scale in 1992 without prior testing of adverse, toxic, or carcinogenic effects. Since that time, numerous reports have appeared describing adverse health effects of individuals exposed to MTBE, both from inhalation of fumes in the workplace and while pumping gasoline. Leakage of MTBE, a highly water-soluble compound, from underground storage tanks has led to contamination of the water supply in many areas of the United States. Legislation has been passed by many states to prohibit the addition of MTBE to gasoline. The addition of MTBE to gasoline has not accomplished its stated goal of decreasing air pollution, and it has posed serious health risks to a large portion of the population, particularly the elderly and those with respiratory problems, asthma, and skin sensitivity. Reports of animal studies of carcinogenicity of MTBE began to appear in the 1990s, prior to the widespread introduction of MTBE into gasoline. These reports were largely ignored. In ensuing years, further studies have shown that MTBE causes various types of malignant tumors in mice and rats. The National Toxicology Program (NTP) Board of Scientific Counselors' Report on Carcinogens Subcommittee met in December 1998 to consider listing MTBE as "reasonably anticipated to be a human carcinogen." In spite of recommendations from Dr. Bailer, the primary reviewer, and other scientists on the committee, the motion to list MTBE in the report was defeated by a six to five vote, with one abstention. On the basis of animal studies, it is widely accepted that if a chemical is carcinogenic in appropriate laboratory animal test systems, it must be treated as though it were carcinogenic in humans. In the face of compelling evidence, NTP Committee members who voted not to list MTBE as "reasonably anticipated to be a human carcinogen" did a disservice to the general public; this action may cause needless exposure of many to health risks and possibly cancers.
1992年，甲基叔丁基醚（MTBE）未经事先对其不良、有毒或致癌作用进行测试，就被全国范围内添加到汽油中。从那时起，出现了大量报告，描述了接触MTBE的个体所遭受的健康不良影响，这些影响既有在工作场所吸入烟雾时发生的，也有在给汽车加油时发生的。MTBE是一种高度水溶性的化合物，地下储油罐发生的MTBE泄漏已导致美国许多地区的供水受到污染。许多州已通过立法禁止在汽油中添加MTBE。向汽油中添加MTBE并未实现其宣称的减少空气污染的目标，而且它已给很大一部分人口，尤其是老年人以及患有呼吸系统疾病、哮喘和皮肤敏感症的人群带来了严重的健康风险。关于MTBE致癌性的动物研究报告在20世纪90年代MTBE广泛引入汽油之前就开始出现了。这些报告基本上被忽视了。在随后的几年里，进一步的研究表明，MTBE会在小鼠和大鼠身上引发各种类型的恶性肿瘤。国家毒理学计划（NTP）科学顾问委员会致癌物小组委员会于1998年12月开会，考虑将MTBE列为“合理预期为人类致癌物”。尽管主要评审员贝勒博士和委员会中的其他科学家提出了建议，但将MTBE列入报告的动议以6票对5票被否决，1人弃权。基于动物研究，人们普遍认为，如果一种化学物质在适当的实验动物测试系统中具有致癌性，那么就必须将其视为对人类具有致癌性。面对确凿的证据，投票反对将MTBE列为“合理预期为人类致癌物”的NTP委员会成员对公众造成了伤害；这一行为可能会使许多人不必要地暴露于健康风险甚至可能是癌症之中。
