Drastic drop in NO2 near schools in lockdown shows what is achievable

Levels of Nitrogen Dioxide (NO₂) fell by just over 40 per cent on main roads in the vicinity of schools in England during the first month of UK’s initial lockdown in early 2020, according to a study carried out at the University of the West of England (UWE Bristol). It highlighted how more people working from home or walking to school can reduce levels of the toxic pollutant, which proves particularly dangerous for children whose lungs are developing.

UWE Bristol researcher Louis Brown, who is part of the University’s Air Quality Management Resource Centre, conducted the study as part of his thesis. He gathered data from AURN (Automatic Urban and Rural Network) monitoring stations, which are set up across the UK. For this work, he selected 93 of the stations that were within 500 metres of primary and secondary schools across England.

Analysis of data taken from the stations on main roads showed a 41% decrease of the pollutant compared to pre-lockdown levels. Data from stations away from main roads but still affected by traffic fumes blown in the wind showed NO₂ levels were down by just over a third.

A significant amount of NO₂ in urban areas is produced from traffic fumes. Inhaling elevated concentrations of the gas in the short term can lead to aggravation of existing respiratory conditions, nose and throat irritation, as well as a possible increase in hospitalisation cases. Exposures over the longer term have also been linked to a series of more serious health issues like bronchitis and greater susceptibility to other respiratory system infections.

Due to their developing organs, children are particularly vulnerable to the negative effects of air pollution inhalation. Louis Brown said: “Children are affected the most by air pollution during school drop-off because mornings are the worst time for car pollution. This means you are taking the most vulnerable elements of society and exposing them to the worst of the day’s pollution.”

He added: “The height of a child also has a bearing on how much pollution they inhale, because smaller children are closer to exhaust pipes and will be more exposed.”

The study, he said, shows what is achievable in terms of reducing children’s exposure to toxic air pollution if more people, outside of a pandemic lockdown, were able to work from home and, if possible, use their cars less for the school run.

As electric cars become more affordable and prevalent, concerns about NO₂ from car pollution will diminish. However, these cars will still produce the same harmful particulates as combustion engine vehicles. “Electric cars will still produce dangerous particulate matter, caused from the wear and tear of tyres and brake pads. Some experts are developing methods of capturing those particles, but until these are commercialised, these particles will continue to cause damage to our health,” said Louis.

Louis’ findings are set out in a paper, set to be published in Science of the Total Environment, a scientific journal covering environmental sciences.