Air pollution doesn't get the attention it deserves. Worldwide, it kills more people than malaria and AIDS combined, and the World Health Organization (WHO) now puts it in the same category as tobacco smoke, UV radiation and plutonium. One significant source of air pollution is burning diesel fuel, especially in older rigs that don't benefit from the most recent pollution control technology.
It's a big problem because another study by the WHO showed that diesel pollution can cause lung cancer. Dr Christopher Portier, Chairman of the IARC working Group, said: “The scientific evidence was compelling and the Working Group’s conclusion was unanimous: diesel engine exhaust causes lung cancer in humans. Given the additional health impacts from diesel particulates, exposure to this mixture of chemicals should be reduced worldwide.“
On top of all this, you can add a new study that concludes that "an estimated 6% of lung cancer deaths in the United States and the United Kingdom – 11,000 deaths per year – may be due to diesel exhaust."
Most at risk are truckers and miners who have high levels of exposure:
Emission standards for diesel engines have become more stringent in recent years, but their exhaust still plays a significant role in lung cancer deaths among truckers, miners and railroad workers, the authors wrote. In addition, diesel exhaust still poses a major cancer threat for people living in dense cities or near highways, they said.
Truckers and miners exposed over their careers to diesel exhaust face a risk of deadly lung cancer that is almost 70 times higher than the risk considered acceptable under U.S. occupational standards. The scientists calculated the lifetime risk for these workers at up to 689 extra lung cancer deaths per 10,000 workers exposed. In comparison, one cancer death per 1,000 workers is used to set federal workplace standards. (source)
While a lot more lung cancer cases are associated with these occupational exposures, those who live in urban areas, especially near highways, are also more at risk than average because of the environmental exposure:
In addition, people in urban areas face a lifetime risk of lung cancer that is 10 times higher than the acceptable risk used in U.S. health standards, according to the study. An estimated 21 per 10,000 people exposed to the amount of diesel exhaust commonly found near U.S. highways would be at risk of dying of lung cancer over their lifetime. That compares to the risk of one death per 100,000 people that is used to set air-quality standards.
A small risk becoming much higher can still stay pretty small, but over large populations, it still represents a lot of people getting sick. We definitely need to clean up diesel and move to clean energy sources for transportation, and design cities better so that the air is healthier. Something as simple as planting lots of trees near where people live has been shown to help reduce particulate matter pollution.