Occupational cancer is caused wholly or partly by exposure to a cancer causing agent (carcinogen) at work, or by a particular set of circumstances at work.
Cancer is not a single disease with a single cause or treatment. It develops when cells in the body grow in an uncontrolled and abnormal way. There are numerous types of cancer, each with its own name and treatment and different types of cancer have their different sets of causes. Many occupational cancers affect respiratory organs, or the skin or liver. An individual’s risk of developing a cancer is influenced by a combination of factors including personal habits such as smoking and alcohol consumption, genetics, personal characteristics such as sex, ethnicity, age, exposure to carcinogens in the environment and so on.
Thousands of people die each year from cancer due to occupational causes. It is estimated that occupational cancers are a leading cause of work-related death worldwide. Asbestos related diseases alone account for at least 100,000 deaths worldwide each year. In the United Kingdom, there are an estimated 2.5 million people living with cancer and over 700,000 are of working age. According to a study in Great Britain over one year, five per cent of cancer deaths (8,000 deaths) were attributable to occupational exposure. The number of workplace deaths caused by accidents in the same period was around 200 - so almost 40 times more deaths are attributable to occupational cancer than to accidents.
In Great Britain, it is also estimated that there are 13,500 cancer registrations (newly occurring cases of cancer) per year attributable to occupations. Therefore it is very important to reduce exposure to carcinogens and potential carcinogens. The British Journal of Cancer and Health and Safety Executive have more information.
It is difficult to determine a true figure for occupational cancers because of the latent nature of the disease. An individual might be exposed to a cause of cancer and not develop any noticeable symptoms until many years later. With current people moving between different job roles and companies, it can be difficult to determine a specific exposure or cause.
What causes occupational cancer?
Occupational cancer is caused by exposure to carcinogens in the workplace. Carcinogens are agents that cause the development or increase the incidence of cancer. There are three different types of occupational carcinogens:
Biological carcinogens - some micro-organisms such as viruses have been known to cause cancer, either by damaging cells directly or by decreasing the body’s ability to control abnormal cells, for example Hepatitis B, HIV viruses and so on.
Chemical carcinogens - a number of chemicals are known to be carcinogenic. These chemicals may occur naturally, such as asbestos, be manufactured like vinyl chloride, or be by-products of industrial processes, for example, polycyclic aromatic hydrocarbons.
Physical carcinogens - agents such as ionising and ultraviolet (UV) radiation have the potential to cause cancer. Examples of ionising radiation include X-rays and alpha, beta and gamma radiation. UV radiation can be divided into a number of bands such as UV-B, UV-C etc, some of which are known to cause skin cancer.
Certain occupational circumstances, such as working as a painter or as a welder are also associated with increased risks of some occupational cancers.
Occupational cancer can arise from exposure to many substances or from certain occupational circumstances such as:
- Asbestos fibres (colorectum, larynx, lung, ovary, pharynx, stomach cancers, mesothelioma)
- Wood dusts (nasopharynx, sinonasal cancers)
- UV radiation from sunlight (skin cancers)
- Metalworking fluids and mineral oils (bladder, lung, sinonasal, skin cancers)
- Silica dust (lung cancer)
- Diesel engine exhaust (bladder, lung cancers)
- Coal tars and pitches (non-melanoma skin cancer)
- Arsenic (bladder, lung, skin cancers)
- Dioxins (lung cancer)
- Environmental tobacco smoke (passive smoke) (lung cancer)
- Naturally occurring radon (lung cancer)
- Tetrachloroethylene (cervix, non-hodgkin’s lymphoma, oesophagus cancers)
- Work as a painter (bladder, lung)
- Work as a welder (lung cancer, melanoma of the eye)
The International Agency for Research on Cancer (IARC) lists over 50 substances which are known or probable causes of workplace cancer, and over 100 other possible substances.
Peer reviewed by:
Dr Lesley Rushton OBE, Imperial College London