The UK’s Parliamentary Office of Science and Technology (POST) has published a new report outlining past and future trends in UK air quality, how pollutants affect health, and the measures that can mitigate poor air quality.
The report highlights how across the UK, concentrations of air pollutants are uneven – with urban areas typically having poorer air quality, particularly in deprived neighborhoods. Particulate matter and gases such as nitrogen oxides and ozone are the air pollutants causing the most concern for human health in built-up cities, towns and suburbs. Different pollutants are often emitted together and react in the air, creating challenges in attributing health effects to individual pollutants.
The report states that no safe lower limit has been identified for these pollutants, which disproportionately affect vulnerable groups. More vulnerable people include children and people who are older, pregnant, or who have pre-existing medical conditions.
Dr James Allan, a research scientist at the National Centre for Atmospheric Science (NCAS) and the University of Manchester, who contributed to POST’s recent air quality briefing, said, “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. However, as air pollution has changed over the years, so [have] its characteristics and important sources, so a continual evolution in strategy is needed to deliver continual improvement.”
People from socioeconomically disadvantaged neighborhoods and from ethnic minority backgrounds are also more likely to be exposed to poor outdoor air quality where they live, as well as being exposed to higher levels of indoor air pollution. Households in the poorest urban areas produce lower air pollutant emissions and are three times less likely to own a car, but are subjected to higher air pollution levels because of where they are located.
Some urban areas exceed the World Health Organization’s global air quality guidelines for particulate matter and nitrogen oxides, and in recent years air quality has been the subject of infringement proceedings by the European Commission against the UK.
The report states that in the majority of urban areas, concentrations of particulate matter and nitrogen dioxide are declining across the UK. Meanwhile, ozone gas – which at ground level is formed by sunlight-driven reactions between nitrogen oxides and non-methane volatile organic compounds – is slightly increasing.
Urban monitoring sites that track pollutant emissions near their source are located across cities such as London, Birmingham and Manchester – and are supported by NCAS and the Integrated Research Observation System for Clean Air (OSCA) project.
Allan added, “The detailed evidence acquired by OSCA will support regional authorities to develop made-to-measure air pollution controls, which respond to changing sources of pollution. Urban air quality research like that led by NCAS will also feed into wider efforts to manage air pollution across the country.”
The UK government is setting two reduction targets for fine particulate matter, also known as PM2.5, to be met by 2040. Modeling forecasts show that most of England has the potential to be compliant by 2030 if sufficient action is taken.
Researchers from NCAS are working with government departments to advise, and provide evidence, on the likely positive and negative effects of different net zero pathways on air pollution, not just in urban areas.