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Wednesday, June 13, 2012

Diesel Exhaust Linked to Cancer

Diesel smoke from a big truck.
After a week-long meeting of international experts, the International  Agency for Research on Cancer (IARC), which is part of the World Health Organization (WHO), today   classified diesel engine exhaust as carcinogenic to humans (Group 1), based on sufficient evidence  that exposure is associated with an increased risk for lung cancer. 

Exposure to diesel exhaust has previously been held to be a causative factor in contributing to a compensable occupational heart condition. Recognizing that the the Workers' Compensation Act required an occupational exposure to be “characteristic” of and peculiar to a particular employment, that there be restricted compensability for disability due to “deterioration of a tissue, organ or part of the body in which the function of the tissue, organ or part of the body is diminished due to the natural aging process,” and that the disease be “due in a material degree to causes or conditions” peculiar to the place of employment, the court concluded that a truck driver may suffer cardiovascular disability as a result of exposure to carbon monoxide even though the employee had other pre-disposing risk factors including smoking, obesity, and a genetic predisposition. The court referred to the example of a teacher who develops asbestosis from working in a classroom with a flaking asbestos ceiling where the disability arising from the asbestos exposure was recognized as being compensable under the New Jersey Workers' Compensation Act. Fiore v. Consolidated Freightways, 140 N.J. 452, 659 A.2d 436 (1995).


In 1988, IARC classified diesel exhaust as probably carcinogenic to humans (Group 2A). An Advisory Group  which reviews and recommends future priorities for the IARC Monographs Program had recommended  diesel exhaust as a high priority for re-evaluation since 1998. 

There has been mounting concern about the cancer-causing potential of diesel exhaust, particularly based  on findings in epidemiological studies of workers exposed in various settings. This was re-emphasized by  the publication in March 2012 of the results of a large US National Cancer Institute/National Institute for  Occupational Safety and Health study of occupational exposure to such emissions in underground miners,  which showed an increased risk of death from lung cancer in exposed workers..


The scientific evidence was reviewed thoroughly by the Working Group and overall it was concluded that  here was sufficient evidence in humans for the carcinogenicity of diesel exhaust. The Working Group  found that diesel exhaust is a cause of lung cancer (sufficient evidence) and also noted a positive  association (limited evidence) with an increased risk of bladder cancer (Group 1).  The Working Group concluded that gasoline exhaust was possibly carcinogenic to humans (Group 2B), a  finding unchanged from the previous evaluation in 1989.

Public health

Large populations are exposed to diesel exhaust in everyday life, whether through their occupation or  through the ambient air. People are exposed not only to motor vehicle exhausts but also to exhausts from  other diesel engines, including from other modes of transport (e.g. diesel trains and ships) and from power  generators.

Given the Working Group’s rigorous, independent assessment of the science, governments and other  decision-makers have a valuable evidence-base on which to consider environmental standards for diesel  exhaust emissions and to continue to work with the engine and fuel manufacturers towards those goals.  Increasing environmental concerns over the past two decades have resulted in regulatory action in North  America, Europe and elsewhere with successively tighter emission standards for both diesel and gasoline  engines. There is a strong interplay between standards and technology – standards drive technology and  new technology enables more stringent standards. For diesel engines, this required changes in the fuel  such as marked decreases in sulfur content, changes in engine design to burn diesel fuel more efficiently and reductions in emissions through exhaust control technology.

However, while the amount of particulates and chemicals are reduced with these changes, it is not yet clear how the quantitative and qualitative changes may translate into altered health effects; research into this question is needed. In addition, existing fuels and vehicles without these modifications will take many years to be replaced, particularly in less developed countries, where regulatory measures are  currently  also less stringent. It is notable that many parts of the developing world lack regulatory standards, and data on the occurrence and impact of diesel exhaust are limited.

Dr Christopher Portier, Chairman of the IARC working Group, stated that “The scientific evidence was compelling and the Working Group’s conclusion was unanimous: diesel engine exhaust causes lung cancer in humans.” Dr Portier  continued: “Given the additional health impacts from diesel  particulates, exposure to this mixture of chemicals should be reduced worldwide.“ Dr Kurt Straif, Head of the IARC Monographs Program, indicated that “The main studies that led to this  conclusion were in highly exposed workers. However, we have learned from other carcinogens, such as  radon, that initial studies showing a risk in heavily exposed occupational groups were followed by positive  findings for the general population. Therefore actions to reduce exposures should encompass workers  and the general population.”

Dr Christopher Wild, Director, IARC, said that “while IARC’s remit is to establish the evidence-base for  regulatory decisions at national and international level, today’s conclusion sends a strong signal that  public health action is warranted. This emphasis is needed globally, including among the more vulnerable  populations in developing countries where new technology and protective measures may otherwise take 
many years to be adopted.”

For over 3 decades the Law Offices of Jon L. Gelman 1.973.696.7900 have been representing injured workers and their families who have suffered work related accident and injuries.