Occupational exposure is when a person is exposed to potentially cancer-causing (carcinogens) chemical, physical or biological substances at work. Exposure to these harmful substances in the workplace may increase a person’s risk of developing certain types of cancer. People who work with cancer-causing substances on the job may be exposed to much higher levels than they would be at home or in their community. As a result, their risk of cancer can be much higher than the average person’s. Finding higher than expected numbers of cancer cases within workers in certain occupations or industry can also provide important clues about the causes of cancer in the general public.
Current scientific evidence suggests exposure to cancer-causing substances on the job is responsible for a small percentage of cancers. Lung cancer, mesothelioma, leukemia and bladder cancer are some of the cancers that have been linked most often to specific occupational exposures. Since higher exposure can lead to greater cancer risk, stopping or reducing exposure is an important part of cancer prevention.
Exposure
Occupational exposure is any contact between the human body and a potentially harmful substance that occurs in the workplace. The highest risk occurs when body surfaces, such as the skin, nasal passages and lungs, come in direct contact with the carcinogen. The cancer-causing substance may be absorbed or inhaled. Specific exposures are related to the type of work and the safety precautions taken to reduce exposure.
Potential health risks may also be associated with how certain industries provide services or production. For example, researchers are studying the impact of shift work (working outside the normal workday, often at nighttime) and how it may be associated with cancer risk in workers.
Exposure in children
Little is known about how parents’ exposure to harmful substances in the workplace is related to the risk of childhood cancer. Researchers suspect that a variety of substances may be related to childhood cancer, such as parental occupational exposure to radiation or certain chemicals. However, there is a lack of consistent findings linking specific occupational exposures of parents to the development of most childhood cancers.
More research is needed to find out which substances, and the length and amount of exposure to these substances, might be related to cancer. Researchers are also trying to find out if there are critical times during a child’s growth and development when exposure might contribute to cancer. For example, some types of exposure might be harmful during pregnancy or before conception.
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Level of risk
The level of risk depends on the amount and length of exposure, how powerful the carcinogen, the presence of other risk factors and a person’s susceptibility. Some workers may have greater and longer exposures to harmful chemicals in the workplace and their risk of cancer may be a lot higher.
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Cancer-causing substances in the workplace
Occupational research studies have identified a variety of cancer-causing chemicals and exposures associated with cancer. Although studies have shown that some exposures increase a person’s risk of developing certain cancers, it may not be possible to conclusively link the cancer to a particular exposure.
- Some workers may be more likely to come in contact with carcinogens. These include construction workers, woodworkers, miners, painters, pesticide workers and workers in the chemical, rubber or dye industries.
- Arsenic, asbestos, benzene, beryllium, cadmium, chromium, ionizing radiation, nickel compounds, radon and vinyl chloride are examples of carcinogens that workers may be exposed to in the workplace.
The Occupational Cancer Research Centre (OCRC) in Canada was established to increase information on the causes and prevention of occupation-related cancers. For more information, visit the OCRC website.
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Information about occupational carcinogens
A number of agencies and organizations evaluate possible occupational carcinogens or provide information about occupational hazards. Some of these agencies and organizations are described below.
- The International Agency for Research on Cancer (IARC) has studied occupational exposure to certain substances and their relationship to cancer. IARC experts classify substances according to their cancer-causing potential in humans based on the strength of scientific evidence. IARC has ranked all carcinogens evaluated to date according to their cancer-causing potential (including possible occupational exposure). For more information on carcinogens that pose a risk, visit the IARC website.
- In the United States, the National Toxicology Program’s Report on Carcinogens contains information on cancer-causing chemicals or substances in the environment or workplace that may potentially increase the risk for cancer.
- Health Canada also provides information about occupational health and safety and potential health risks associated with exposure to various chemicals and substances in the workplace. Health Canada works with Canadian businesses and other organizations to build a healthier Canadian workforce. Health Canada works to develop health policies and best practices in the workplace and coordinates the Workplace Hazardous Materials Information System (WHMIS), a communication system that provides health and safety information to Canadian workers about hazardous materials in the workplace.
- The Canadian Centre for Occupational Health and Safety (CCOHS) provides Canadian workers and workplaces with information to address common occupational and environmental health and safety concerns. It also promotes occupational health and safety in Canada. CCOHS provides a brief list of cancer sites that are associated with certain occupational exposures. For more information about the list of cancers and occupational exposures, visit the CCOHS website.
- CAREX Canada provides general information about a large number of known or potential cancer-causing substances. It also provides estimates of how many Canadians are exposed to each substance in the workplace and the environment in general.
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Reducing your risk
You can take action to prevent your occupational exposure to harmful substances, especially in situations where exposure is high or where the carcinogen is highly potent. Where occupational exposure cannot be prevented, it should be reduced to the lowest possible level.
Employers should do the following to help reduce the risk posed by hazardous materials:
- Educate workers about cancer and inform them about possible exposure to carcinogens in the workplace. Workers have the right to know what they might be exposed to before they’re exposed.
- Eliminate or reduce exposure to cancer-causing substances by removing them or by using a different substance.
- Set up processes and make changes to the workplace so that workers have a minimal exposure to hazardous substances, including carcinogens.
- Employers must set up education and training programs for workers exposed to hazardous products in the workplace. Employers must also make sure that products are labelled, a Material Safety Data Sheet (MSDS) is present for each product and they are readily available to workers.
Workers should do the following to help reduce their risk from occupational exposures:
- Follow the employer’s occupational health and safety instructions when using, storing and disposing of hazardous materials.
- Use all the protective clothing and equipment provided by the employer to help minimize the risk of exposure to potentially harmful substances.
- Follow government and manufacturers guidelines for handling harmful substances.
- Materials in the workplace have a Material Safety Data Sheet (MSDS). This document contains information on the potential hazards, health effects of exposure and how to work safely with the product. These guidelines are printed on the packaging and are posted in the workplace.
- Canada’s Workplace Hazardous Materials Information System (WHMIS) identifies the hazards of a chemical and provides information on the safe use of hazardous materials. WHMIS information is provided through product labels, MSDS information and worker education programs.
- Participate in training programs and use this information to work safely with hazardous materials. Tell employers when labels on containers have been accidentally removed or if the label is no longer readable.
- Report accidental exposure immediately.
Occupational research studies have given employers the knowledge to take actions aimed at reducing or preventing exposures to carcinogens in the workplace. Overall, the risk of exposure in the workplace today is much less than in the past because occupational health and safety practices have greatly reduced or eliminated exposure to cancer-causing materials.
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