What is a carcinogen?
Your risk of cancer can increase through exposure to cancer-causing agents, known as carcinogens. These may be biological, physical, or chemical. As some are distinct from modifiable risk factors (like smoking, drinking alcohol, or suntanning), exposure to carcinogens may occur outside your control.
Involuntary exposure to carcinogens tends to come to the public’s attention through reports in the media concerning particular issues (like use of pesticides, contaminants of food, hazards associated with cosmetics, etc.).
While not all exposures cause cancer, some can damage the DNA in our cells, which may lead to cancer over time.
Environmental causes of cancer - a breakdown
Biological risk factors
Biological carcinogens come from living things like viruses, bacteria, or parasites. Not all infections cause cancer, but some can increase your risk. Examples include:
- Human papillomavirus (HPV) – linked to cervical, anal, and some throat cancers.
- Hepatitis B and C viruses – linked to liver cancer.
Vaccines, antibiotics, and hygiene can reduce the risks from many types of infection.
Physical risk factors
Physical carcinogens usually involve exposure to things like radiation or sunlight. These can damage body tissues and increase cancer risk. Examples include:
- Ultraviolet (UV) radiation from the sun – the main cause of skin cancers such as melanoma.
- Asbestos – once widely used in buildings, asbestos can cause lung cancer and mesothelioma when inhaled.
Taking steps like using sun protection, limiting exposure to radiation, and removing asbestos safely can help reduce these risks.
Chemical risk factors
Many chemicals we encounter in everyday life or at work can increase cancer risk. These may be found in air pollution, food, household products, or workplaces. Examples include:
- Tobacco smoke – a leading cause of cancer, including lung, mouth, throat, and bladder cancers.
- Air pollution – especially in busy cities, can increase the risk of lung and other cancers.
- Pesticides and industrial chemicals – long-term exposure to some chemicals may increase cancer risk.
- Alcohol – drinking alcohol is linked to several cancers, including breast, liver, and bowel cancers.
Reducing exposure to harmful chemicals, quitting smoking, and limiting alcohol can help lower your risk.
What can you do?
Not all environmental exposures can be avoided, but there are steps you can take to reduce your risk:
- Be aware of potential hazards in your home and workplace.
- When the UV level is three or above, remember to be SunSmart.
- Quit smoking and avoid second-hand smoke.
- Limit alcohol and processed food intake.
Understanding environmental causes of cancer helps us make healthier choices and reduce your risk.