The World Health Organization announced this week that diesel exhaust is now a known cause of cancer. It was previously classified a probable cause. Since millions of people are exposed to diesel exhaust, this is a matter of more than passing concern. Trucks, school buses and home generators are common users of diesel fuel. People working with diesel fuel are at increased risk, but so are passengers, pedestrians and bikers on city streets. How big is the risk? Careful studies reveal a risk of 540 excess cancer deaths per million people. In a city of ten million people, over five thousand extra lifetime cancer deaths will occur due to diesel exhaust.
Cancer is not the only health hazard posed by diesel exhaust, which is a complex mixture of over one thousand gases and carries over forty known kinds of micro-particles that are toxic. These are so tiny that they penetrate deep into the lungs with every breath. There they cause many inflammatory effects in addition to increasing the risk of cancer. Asthma, bronchitis, chronic lung disease and other lung problems are all worsened by diesel exhaust.
Improvements in diesel engines and fuel are cutting down the quantity of toxic contaminants, but the risk is still substantial. The take-home message is that it’s wise to minimize exposure to diesel fuel and exhaust as much as possible, especially for children and people with any kind of lung problem!