Particularly worrisome are the high levels of hydrocarbons emitted by Japanese, German and Italian two-wheelers, according to the study. Some hydrocarbons have been linked to global warming, while others are suspected of being carcinogenic. Motorcycles aren't a primary means of transport in most developed countries, the authors note. As a consequence, they say, "the importance of [motorcycle] emissions has been underestimated in legislation, giving manufacturers little motivation to improve aftertreatment systems."
Until recently, for instance, U.S. emission standards for highway motorcycles hadn't been updated in 25 years, despite the fact that these vehicles produced more harmful exhaust emissions per mile than cars or even large sports utility vehicles, according to the Environmental Protection Agency. However, a new EPA rule, which goes into effect in January, will require manufacturers to reduce combined emissions of hydrocarbons and nitrogen oxides in motorcycle exhausts by 60 percent. When the rule takes full effect in 2010, the EPA estimates it will reduce emissions of these pollutants by about 54,000 tons a year, and save approximately 12 million gallons of fuel annually by preventing it from evaporating from fuel hoses and tanks.
The American Chemical Society - the world's largest scientific society - is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
The online version of the research paper cited above was initially published Nov. 25 on the journal's Web site. Journalists can arrange access to this site by sending an e-mail to firstname.lastname@example.org or calling the contact person for this release.