Radiation, pollution and cancer

Outdoor air pollution

Air pollution is linked to a slightly increased risk of cancer. Air pollution can be human made:

• vehicle fumes
• smoke from burning fuels

It can also be natural pollutants such as

• desert dust
• radon gas

Research shows that a pollutant called “particulate matter” increases the risk of cancer, especially lung cancer. Particulate matter is in diesel and petrol exhaust fumes (and tobacco smoke).

In the UK, levels of particulate matter and other air pollutants are low. Levels are higher in some cities, and they can vary according to factors such as the amount of traffic and weather conditions.

But it’s important to remember that smoking increases your cancer risk much more than air pollution does. If you are concerned about air pollution, visit IQair for more information about air quality wherever you are.

Indoor air pollution

The main sources of indoor air pollution are tobacco smoke and radon gas. Exposure to tobacco smoke in your home increases your risk of lung cancer. Even if you aren’t the smoker, you are at risk by breathing second-hand smoke.

Radon is radioactive gas that occurs naturally and is found in rocks and the soil. It’s linked with a slightly increased risk of lung cancer. In areas where the gas occurs in high concentrations (such as south-west England and parts of Wales), it can build up to high levels.

In the UK, if you live in an area with high levels of radon, guidance is available from UK Radon on how you can reduce the amount of radon exposure to a safe level.

But only around 5% of lung cancer cases in the UK are associated with radon. Most of these cases are actually caused jointly by radon gas and smoking – radon is more likely to cause lung cancer in people who smoke. Estimates suggest smokers are 25 times more at risk from radon than non-smokers.

Radiation

Some types of radiation can cause us harm, including raising the risk of cancer, if we’re exposed to too much of it. Ionising radiation has enough energy to damage DNA and increase the risk of cancer. Non-ionising radiation has lower energy and is less harmful to living tissue. It has not been found to increase the risk of cancer, unless exposed at much higher levels than experienced in daily life.

However, some technologies are new, or the ways in which they are used have changed. In these cases, there’s not yet enough data for scientists to be certain about the level of cancer risk.

Most people experience low levels of radiation in their daily lives which carry a very small health risk, if at all.

Ionising radiation: naturally occurring radiation

Naturally-occurring radiation is ionising radiation given off by natural sources (see radon). The vast majority of people are rarely exposed to amounts high enough to cause damage.

Ionising radiation: medical radiation

Our main exposure to ionising radiation is through medical X-rays and body imaging such as radiography. While you want to avoid unnecessary scans, medical X-rays are generally used where they are the best solution. In this instance, the need for the investigation outweighs the small potential risk.

Where possible, doctors will recommend other types of imaging that don’t use radiation (such as ultrasound or an MRI scan). Talk to your doctor if you have concerns about having an X-ray, and tell them about any previous ones you may have had.

Ionising radiation: airport scanners

Most airports now use body scanners as part of their security measures and use either radio waves or ionising radiation. In both cases, the doses are small and do not increase your cancer risk.

Non-ionising radiation: mobile phones

Using mobile phones does not increase the risk of cancer. The electromagnetic radiation from phones is very weak and does not have enough energy to damage human, making it highly unlikely to cause cancer. While research is ongoing to investigate any potential long-term effects, no evidence has been found so far linking mobile phone use to cancer risk.

Non-ionising radiation: power lines

The type of radiation given off by power lines is low-frequency electromagnetic radiation. This does not have enough energy to damage human cells and thereby cause cancer. But some studies have suggested a link between exposure to magnetic fields and a small increase in the risk of childhood leukaemia.

The evidence for this is limited but a risk cannot be ruled out. There has been no link with health risks in adults.

Non-ionising radiation: computer screens

Computer screens and monitors do emit electromagnetic radiation, but only at low levels. These levels are far below the safe levels laid down by international recommendations.

Modern computers have conductive screens – the static field is similar to background radiation.

Non-ionising radiation: microwave ovens

Microwave ovens do produce electromagnetic radiation, but most countries have safety standards for their manufacturing. While some studies have suggested a possible link between microwave ovens and cancer, most research shows no connection. If your microwave is in good condition and you follow the instructions, it is safe to use.

Cooking food in microwave ovens does not cause cancer either. Check out our recipes section for healthy eating inspiration.

Occupational exposure

Exposure to radiation, asbestos, pesticides and other chemicals at work can increase the risk of developing cancer, but this mainly affects a small number of people in specific jobs, usually after many years of heavy exposure. Most countries have strict regulations to protect workers from these hazards, significantly reducing risks in recent years.

Smoking can worsen the risk of cancer related to workplace exposures. For example, asbestos workers who smoke have a much higher risk of lung cancer. To lower your risk, follow your employer’s safety guidelines and avoid other risk factors, especially smoking.

Night shift work

Some studies suggest people who work night shifts or expose themselves to artificial light at night could increase their risk of cancer, in particular breast cancer. But many of these studies looked only at breast cancer in animals. This did not prove that shift work increases the risk of breast cancer in humans.

In 2019, the International Agency for Research on Cancer (IARC) said that night shift work “probably” increases the risk of cancer. They based this on the available evidence at the time. More recently, a review of 10 different studies in humans showed that night shift work is unlikely to increase your risk of breast cancer.

This research also found that women who work night shifts are more likely to be living with overweight or obesity than women who don’t work night shifts. Overweight and obesity increase the risk of at least 13 types of cancer, including breast cancer.

This may be because the working patterns make it more difficult to:

• shop for healthy food
• cook healthy food
• take part in regular physical activity.

Based on all the research there is not enough reliable evidence to suggest that night shift work causes breast cancer.