Smoking is one of the leading causes of lung cancer, followed by exposure to asbestos and radon. But not many people are aware that exhaust fumes from diesel fuels is also one of the potent risk factors for developing this deadly form of cancer.
In 2012, International Agency for Research on Cancer (IARC), part of the World Health Organization, upgraded the existing classification of diesel exhaust from “possibly carcinogenic” to “definitely carcinogenic” to humans. This means it is now confirmed that diesel exhaust is an established cause of cancer. Diesel exhaust now belongs in the same category as other carcinogens such as alcohol, asbestos, plutonium and sunlight.
Dr Christopher Portier, Chairman of the IARC working Group, stated in a press release that “The scientific evidence was compelling and the Working Group’s conclusion was unanimous; diesel engine exhaust causes lung cancer in humans.”
However, this new classification doesn’t indicate the extent of exhaust exposure that can trigger cancer causing DNA damage. Neither does it suggest the risk implications for the general population. People who work with diesel vehicles such as buses, trains and tractors are more likely to succumb to the cancer risk.
Another study by the Environmental Health News, revealed that up to 6 percent of lung cancer deaths in the US and the United Kingdom can be attributed to diesel exhaust. The study reported that the risk of lung cancer for miners and truck drivers is nearly 70 times higher than the risk considered acceptable under U.S. occupational standards. The study further reports that “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.”  
What is in diesel exhaust?
When diesel fuel burns inside an engine, a complex mixture of gases and particulate matter (soot) is emitted.
- Gaseous compounds include carbon dioxide, carbon monoxide, sulphur and nitrogen compounds and hydrocarbons with extremely low molecular weight.
- Particulate matter is composed of carbon, metals, and a number of organic compounds including Polycyclic aromatic hydrocarbons (PAHs).
How do diesel exhaust fumes cause cancer?
These toxic gases and microscopic soot particles pose severe risks to public health.
Diesel exhaust could be carcinogenic due to a combination of mechanisms. First, owing to their microscopic size, PAH’s can be easily inhaled. (The particles from the diesel exhaust are less than 10 micro-metres). These particulate matters penetrate deeper into the lungs and become lodged there – leading to low grade, chronic inflammation.
The resulting inflammation can also influence the rate at which mutated cells divide; more specifically it can put these cells at an increased risk to grow and spread if they happen to pick any random mutations.
The inhaled PAHs could also cause direct damage to the DNA in the lungs’ cells – causing cancer.
Exposure to diesel fumes
The main pathway of diesel exhaust exposure is through inhaling the soot particles and gases suspended in the air. People can be exposed at work, at home and when they are travelling. The amount to which people are generally exposed varies, and quantifying these exposures can be especially challenging. The toxic ingredients of the exhaust fumes are also found in other sources – making it difficult to assess and measure the associated health risks.
The pervasiveness of engines powered by diesels have made it impossible to escape from the toxic fumes; irrespective of where you live. However, people with substantial and extended exposures – such as miners, truckers, equipment operators and railroad workers – are always at an increased risk of developing lung cancer than those not exposed as much.
Fortunately, these emissions from the combustion of diesel fuels have been reduced substantially over the past decades. Advances in diesel engine technology; for example, low-sulphur fuel, engines that burn diesel more efficiently and exhaust after-treatment, have not only resulted in a noticeable decline in the poisonous matter but have also altered the toxic chemical and physical make-up of the diesel exhaust, rendering them less harmful.
Over 50,000 diesel engines were eliminated in the US between 2008 and 2010, and 230,000 tons of diesel-derived pollutants have been removed from the environment, reports the EPA.
Lung cancer is not the only risk
While the risk of lung cancer is more dominant for a certain group of people with prolonged and heavy exposure, diesel exhaust can trigger a wide range of health problems in the general population as well.
Toxic emission can irritate the eyes and the entire respiratory system – including nose, throat and lungs. It can result in headaches, nausea and coughs. Previous studies have shown that the fine exhaust particles make allergy inclined people more vulnerable to their allergies. Exhaust can inflame the lungs – exacerbating the symptoms in people affected with impaired respiratory system and increasing the incidence or intensity of asthma attacks.
The elderly, and children with their still developing immune, lungs and respiratory systems are even more defenceless against such toxic exposure. According to a report by California Environmental Protection Agency's Office of Environmental Health Hazard Assessment (OEHHA), “Exposure to fine particles is associated with increased frequency of childhood illnesses and can also reduce lung function in children.”
How can you protect yourself?
How can you protect yourself from the air pollutants emitted by the all-pervasive diesel fumes? While it may not be possible to avoid the exposure altogether, you can still do a lot to strengthen your body’s defences. Eating a diet rich in a wide variety of fruits, nuts and vegetables will enrich the body’s pool of anti-oxidants – providing the ultimate protection to the cellular structures against free radical’s attack that trigger inflammation and cellular damage.
You can also up your anti-oxidant arsenal by supplementing with vitamin C and magnesium. Both these nutrients possess powerful anti-inflammatory and anti-oxidant properties and support the body in its fight with environmental toxins and help it detoxify and cleanse with efficiency.
Vitamin C is known to manage symptoms of asthma, wheezing, bronchitis and a range of other respiratory disorders. Similarly, magnesium, through several different mechanisms, can also alleviate asthma symptoms and improve the quality of life in people with mild to moderate asthma .
In addition, Vitamin C has also been extensively studied “as a treatment for cancer patients since the 1970s,” according to the National Cancer Institute, and shows promising potential as an integrative therapy to treat and manage many types of cancer.
- Vermeulen R, DT Silverman, E Garshick, J Vlaanderen, L Portengen, K Steenland. Exposure-response estimates for diesel engine exhaust and lung cancer mortality based on data from three occupational cohorts. Environmental Health Perspectives. 2013.
- Brian Bienkowski. Diesel responsible for 6 percent of lung cancer deaths, study says. Environmental Health News. November 2013.
- Kazaks AG, Uriu-Adams JY, Albertson TE, Shenoy SF, Stern JS. Effect of oral magnesium supplementation on measures of airway resistance and subjective assessment of asthma control and quality of life in men and women with mild to moderate asthma: a randomized placebo controlled trial. Journal of Asthma. 2010 Feb;47(1):83-92.