Pollution in the air, water and soil or radiation from the sun, x-ray or radiation therapy are possible causes of cancer.
Cancer risk depends on how long, how often and how much exposure occurs along with other factors. Some harmful substances can also cause cancer years after being exposed to them.
The International Agency for Research on Cancer (IARC) groups substances on how likely they are to cause cancer. These groups include: cause cancer, probably cause cancer, possibly cause cancer and not classifiable (due to insufficient evidence or it is unknown if they cause cancer).
Environmental cancer risks in Aotearoa/New Zealand
Environmental protection standards in Aotearoa, New Zealand are higher than in many countries. These standards help to lower environmental cancer risks. But risk does still exist. Potential cancer risks include:
Air pollution is caused by the burning of fuels from transport, industry, power, cooking and heating (wood and coal).
Water pollution includes nitrate contamination of some of our waterways. Nitrates come from fertilisers used in farming, horticulture and farm animal waste. High nitrate levels in our drinking water have been linked to cancer especially bowel cancer.
The International Agency for Research on Cancer, IARC, classifies nitrates as ‘probably’ cause cancer in humans.
For more information about the safety of our drinking water:
- Ministry of Health Drinking Water
- Public Health Units
- Drinking water study raises health concerns for New Zealanders
The management of drinking water supplies will be shifting from the MOH to a new regulator, Taumata Arowai from mid-2021:
Soil pollution can come from natural or manmade sources such as from arsenic or fertilisers. Arsenic in contaminated soils is a known cause of cancer that can pollute drinking water, especially privately owned bores.
For more information:
There are potential hazards that can cause cancer exist in our everyday work and home renovations.
- Asbestos founds in homes built between 1940-1990 pose risk for asbestos-related cancers. To protect your health against asbestos in the home or workplace:
Ministry of Health information on asbestos
- Lead based paints used until the 1980s also pose cancer risks to people who are redecorating. How to reduce your risk:
Ministry of Health information on lead-based paints
Being exposed to radiation is a known cause of cancer.
We are exposed to background radiation from natural sources every day. Some sources of radiation are more harmful than others.
The main types of radiation include:
- Ultraviolet radiation from sunlight is a known cause of skin cancer.
Find out more about skin cancer
- Ionising radiation occurring naturally, such as from radon in soils, but mostly from artificial sources. Radon found in soils is the main source of naturally occurring radiation in Aotearoa. Levels here are low and do not pose a big cancer risk:
Find out more about Radon
- Medical radiation such as from x-rays, CT scans, fluoroscopy or nuclear medical scans are used to manage health problems. The small doses of radiation used in these medical tools are not harmful.
Find out more about medication radiation
- Non-ionising radiation or very low frequency electromagnetic fields comes from natural and electrical sources (powerlines, wiring and electrical appliances such as microwaves, computers, electric blankets and mobile phones). IARC classifies radiofrequency fields a ‘possibly’ cancer causing.
Find out more about non-ionising radiation