Air pollution remains the most significant environmental threat to human health in the UK. While air quality has improved over the decades, evolving pollution sources mean that scientists and policymakers must continually adapt their strategies. From urban hotspots to vulnerable communities, the impacts of air pollution are unevenly distributed. 

Did you know that exposure to poor air quality affects people’s health across the lifespan, including premature birth rates, lung development, cardiovascular and respiratory health, and neurological diseases?

Find out about air pollution, how researchers are helping to tackle this issue, and what steps are being taken to protect public health.

Air pollution is the presence of harmful substances in the air, such as gases, dust, or chemicals that come from a variety of sources.

Particulate matter pollution is caused by tiny solid or liquid particles suspended in the air, released by industrial processes, wildfires, dust storms, vehicle exhausts and tyres.

Ammonia is a colourless but pungent gas, also released from industry and vehicles – but mainly from agriculture’s livestock waste and fertiliser application.

Nitrogen oxides and sulphur dioxide are gases released by burning fossil fuels – in engines and power plants – and when ammonia reacts with them, particulate matter is made.

Volatile organic compounds are released from many sources including paints, solvents, and vehicle exhausts – and when they react with nitrogen oxides in sunlight another pollutant ozone is created, which is a key component of smog.

Carbon monoxide is a colourless and odourless gas, emitted from vehicle engines, burning wood, and industrial activities.

Dr James Allan, a research scientist at the National Centre for Atmospheric Science (NCAS) and the University of Manchester, explains that while air pollution in the UK has improved over the decades, it is still currently the single biggest environmental problem affecting human health in the UK.

Particulate matter, nitrogen oxides, and ozone are among the most harmful airborne pollutants in cities, towns, suburbs, and rural areas. These pollutants are often emitted together and undergo chemical reactions in the air, making it difficult to pinpoint specific health effects.

No safe lower limit has been identified for these pollutants, meaning that even low concentrations can negatively impact health, especially among vulnerable populations such as children, the elderly, pregnant women, and individuals with pre-existing conditions.

“While air pollution is a nationwide concern, certain groups bear the brunt of its impact. Socio-economically disadvantaged communities and minoritised ethnic communities are more likely to live in areas with high pollution levels, and are disproportionately exposed to pollutants from traffic, industry, and other sources beyond their control,” sets out Dr Sarah Moller, a senior air pollution scientist at NCAS and the University of York.

Most urban areas exceed the World Health Organization’s Global Air Quality guidelines for particulate matter and nitrogen oxides, highlighting the urgent need for continued action – particularly for the people who work, live, and study in cities, towns, and suburbs.

Research is at the heart of efforts to improve air quality. Scientists at NCAS support pollution monitoring across major cities such as London, Birmingham, and Manchester. These monitoring stations provide crucial emissions data that helps local authorities develop targeted pollution controls.

In addition to monitoring, researchers analyse the chemical composition of pollution particles to determine which are most harmful to human health.

“The chemicals found in particles change depending on their source and transformations in the atmosphere. There is evidence that PM2.5 (PM2.5 refers to fine particulate matter that is 2.5 micrometers or smaller in diameter, about 30 times thinner than a human hair) contains toxic compounds such as metals, including lead, arsenic, nickel and cadmium and organic compounds such as polyaromatic hydrocarbons. These are currently measured in the UK, but it’s clear that there are many more harmful chemicals in the air and further work is needed to develop strategies to reduce these,” explains Professor Jacqui Hamilton, NCAS Science Director and air quality researcher at the University of York.

NCAS researchers are participating in multi-disciplinary projects bringing together atmospheric scientists, toxicologists, epidemiologists, clinicians and public health experts to design new experimental approaches to identify which sources of particles are most damaging to human health. By identifying the most damaging pollutants, we can inform policy decisions to limit their impact.

Ambitious targets have been set for England to reduce fine particulate matter, known as PM2.5, by 2040. Forecasts suggest that most of England could meet these targets by 2030 if strong action is taken.

Efforts to mitigate pollution include road charging schemes, regulations on domestic and industrial fuel use, advancements in low-emission agricultural technologies, promoting cleaner transport alternatives, and reducing emissions of toxic pollutants. Despite these measures, the UK’s Chief Medical Officer insists that “we can and should go further to reduce air pollution.”

With air pollution continuing to pose a significant health risk, scientific research plays a vital role in shaping policies and technologies to address the problem. By understanding pollution sources, monitoring its effects, and developing innovative solutions, researchers are helping pave the way for a cleaner, healthier future for all.