For the first time, American scientists have revealed how diesel fumes causes cancer.
Qinghua Sun, an assistant professor of Environmental Health Sciences at Ohio State University, says that diesel exhaust has the ability to induce the growth of new blood vessels that serve as a food supply for solid tumours.
The researchers found that in both healthy and diseased animals.
According to them, more new blood vessels sprouted in mice exposed to diesel exhaust than did in mice exposed to clean, filtered air.
They say that this finding indicates that previous illness is not required to make humans susceptible to the damaging effects of the diesel exhaust.
The researchers say that inhaled diesel particles are very tiny in size, which is why they can penetrate the human circulatory system, organs, and tissues.
This suggests that diesel fumes can cause damage just about anywhere in the body, they add.
Diesel exhaust exposure levels in the study were designed to mimic the exposure people might experience while living in urban areas and commuting in heavy traffic.
The levels were lower than or similar to those typically experienced by workers who use diesel-powered equipment, who tend to work in mines, on bridges and tunnels, along railroads, at loading docks, on farms and in vehicle maintenance garages, according to the U.S. Department of Labor.
"The message from our study is that exposure to diesel exhaust for just a short time period of two months could give even normal tissue the potential to develop a tumour," said Qinghua Sun, senior author of the study.
"We need to raise public awareness so people give more thought to how they drive and how they live so they can pursue ways to protect themselves and improve their health. And we still have a lot of work to do to improve diesel engines so they generate fewer particles and exhaust that can be released into the ambient air," Sun added.
A research article on the study, supported by Health Effects Institute awards and grants from the National Institutes of Health, has been published in the online edition of the journal Toxicology Letters.