Ethanol, an alcohol-based compound derived from plants is in the forefront of candidates to replace fossil fuels. As oil supplies run low, and nations get more conscious about the environment, technology harnessing the power of the substance is moving forward.

However, a new study shows that ethanol may be just as health-threatening as natural gas. The ethanol exhaust from the smoke of vehicles blends in with smog and creates a poisonous brew that is dangerous to living organisms. The study says that about 200 more people will die annually if the US was to undergo a complete switch.

"If you want to use ethanol, fine, but don't do it based on health grounds. It's no better than gasoline, apparently slightly worse," says Mark Jacobson. Jacobson is the head of the study and is an environmental engineer at Stanford University. "It's not green in terms of air pollution," he adds.

Jacobson's study was modeled using computer applications. The conclusions derived are based on actual data which was processed to provide an approximation of Ethanol's effects. The study is to be published in the Environmental Science and Technology journal.