Health Advice

Air pollution and health in Wales

Health effects

Outdoor air pollution is the largest environmental risk to health.

Pollutants such as fine particulate matter (called PM2.5) and nitrogen dioxide (NO2) can cause some health problems and make others worse.

Breathing in these pollutants long-term can increase health risks from heart and lung diseases, and lung cancer. There is also evidence of effects on dementia, low birth weight and diabetes. Shorter-term exposure symptoms can include eye, nose and throat irritation. The health effects of pollution depend on how much of it people are exposed to and for how long.

Air pollution affects people in different ways; risks and impacts change over a lifetime too. Children, older people and those with heart or lung problems are more likely to be affected. Children can suffer from poor lung development and asthma symptoms because of air pollution exposure. People who work in highly polluted places or who regularly travel in or through polluted areas (such as city centres) may also be at higher risk of pollution-related health problems. People who live in the most deprived areas – where health and air quality tend to be poorest – are also more likely to be harmed by air pollution exposure.

Air pollution monitoring data and forecasts

The Daily Air Quality Index has been developed to provide advice on expected levels of air pollution. In addition, information on the short-term effects on health that might be expected to occur at the different bands of the index (Low, Moderate, High, Very High) is provided.

Up-to-date local and regional information on air pollution concentrations across Wales is available here.

Estimating impacts

Estimating the health impact of air pollution is difficult.

The UK expert Committee on the Medical Effects of Air Pollution (COMEAP) has previously estimated that air pollution is responsible for “an effect equivalent of between 28,000 and 36,000 deaths (at typical ages) each year”. This does not mean there are ‘actual’ deaths from air pollution exposure; rather, that the reduced life expectancy which everyone experiences because of air pollution exposure (6-8 months on average, but could range from days to years), is ‘equivalent’ to between 28,000 and 36,000 deaths when summed.

In Wales – based on modelled air pollution data pre-pandemicPublic Health Wales estimated the burden of long-term air pollution exposure to be around the equivalent of 1,000 to 1,400 deaths each year. This estimate was calculated using a more accurate, method that considers the combined effects of different pollutants, meaning that the overlapping effects of PM2.5 and NO2 are accounted for.

Impact estimates are uncertain, however, which is why they should always be presented as a range of values, rather than a single, central estimate. The estimates are also relevant only to a single time and place and should not be used for comparisons.

Although estimating the burden of air pollution is difficult, there is clear and strong evidence that it does harm health. It is therefore important to take action to reduce air pollution and the harms that go with it.

Covid-19 pandemic and air pollution trends

The emergency public health restrictions introduced during the pandemic (e.g. lock down and working from home polices) showed just how closely travel, transport and air pollution are connected.

In work commissioned by Welsh Government, the changes in concentrations of different air pollutants during lock-down phases were assessed. It showed that travel and transport are significant contributors to air pollution, and that changes in the need to travel and mode of travel can improve air quality.

Policies that recognise these changes and aim to support them being adopted in the long-term are likely to benefit air quality and health.

The pandemic response also had other impacts on air quality in Wales. While the lockdown decreased exposure to some traffic related pollution, it may have increased exposure to air pollution in the home. With more home working in the future, research is needed to understand our exposure to indoor air pollution. For example, Public Health Wales has heightened its surveillance around carbon monoxide exposure to reflect the fact that more people are spending time at home, while during the first lockdown, many agencies noted an increase in neighbourhood waste and garden fires due to recycling facilities being closed and people being at home.