40% of UK schools report excess NO2 levels in 2021. London ranks highest for poor air quality and deprived areas suffer the most

A new academic year has started and, while the excitement of new challenges beckons some problems persist - especially high air pollution levels around schools. Cleantech platform Airly recently carried out a survey, using available air pollution monitoring sources which indicates that nitrogen dioxide (NO₂) levels were at a higher level than World Health Organization acceptable levels at 41% of British schools.

What is NO₂?

Nitrogen dioxide is a pollutant gas which heightens the risk and worsens the symptoms of asthma in children. NO₂ reduces lung function and increases the probability of inflammation of the airways. The main sources of NO₂ are road traffic, because of fuel combustion, and heavy industry.

During the recent lockdowns, air quality around schools improved but during the last year, it has returned to the excessive ‘normal’. The following charts show the problem by timeline. It is clear that NO2 levels around London’s schools are the highest in the UK.

41% of schools in the UK exceeded the WHO’s acceptable levels of NO₂ in 2021. This shows a significant improvement from 2019 when 49% of British schools exceeded the WHO’s limit. The lowering of NO₂ levels during the lockdown in spring  and summer of 2020 illustrates clearly the extent to which human activity impacts NO₂ levels.

Pollutants like NO₂ and PM10 have a negative influence on both health and a child’s learning ability. Several contemporary studies have proven that air pollution can impair cognitive intelligence, while other studies indicate that a reduction in air pollution can markedly improve the memory of young people.

The study also shows that children living in the UK’s poorest regions endure higher levels of air pollution. The analysis of the mean PM10 pollution levels, the most common pollutant measured, around schools in the UK showed that there is a correlation between PM10 concentration levels and the neighbourhood’s IMD Score. This next graph displays the relationship between IMD Score and air pollution around schools, grouped in boroughs, with selected boroughs highlighted.

These poorer areas have a greater level of air pollution for several reasons including the amount of older cars in the area, denser housing populations, a lack of green urban areas, which is part of the industrial revolution’s legacy, and worse aero sanitary conditions. 

How can schools improve their air quality? 

To lower air pollution near schools, it is of paramount importance to understand the level of pollution there is in the vicinity of the school. It is therefore necessary to monitor the air quality outside, to measure the air quality in the school’s nearby surroundings on an ongoing basis and to analyse pollution peaks to effectively reduce these pollution levels. Airly introduced the #LetSchoolsBreathe campaign to supply 50 air quality sensors to schools in the UK to enable them to monitor air quality in their surroundings on an ongoing basis. After six months, each school is to receive a report analysing  concentrations of nitrogen dioxide and PM concentration and suggestions on what steps to take to improve the situation.

These steps may be to reduce car traffic near the school, rearrange the paths to the school to reduce the risk of pollution for students, or increase the amount of green space near the schools.