What’s happening? The average level of air pollution in cities worldwide is around four times higher than health-related maximum levels recommended by the World Health Organization (WHO), according to a study by OpenAQ. The organisation found average annual levels of particulate matter, PM2.5, in 33 cities was 39 µg/m3, compared to the WHO-recommended 10 µg/m3. OpenAQ found the cities with the highest levels of particulate matter, which is caused partly by car exhausts and affects human health, were all in Pakistan, India, Bangladesh and China. (Engineering and Technology)

Why does this matter? The impacts of air pollution are felt globally, with around 90% of the world experiencing harmful exposure to it. As a major contributor to human health issues, air pollution levels that are so far past maximum recommended limits are concerning.

The broader context – Air pollution is known to trigger or exacerbate respiratory conditions, such as asthma and chronic obstructive pulmonary disease. Beyond this, the problem is being linked to an increasing range of other health issues than previously understood. A University of Edinburgh study has indicated childhood exposure to air pollution may negatively impact cognitive skills up to 60 years later. Long-term exposure to nitrogen dioxide (NO2) or fine particulate matter in atmospheric pollution has also been tied to mental health issues such as depression and potential memory decline for over a decade after exposure.

Additionally, recent research from Harvard University has found air pollution related to fossil fuel use was responsible for over eight million deaths worldwide in 2018 – significantly higher than previous estimates of fossil fuel pollution-related mortalities.

Has the pandemic changed anything? Yes and no. For example, lower traffic levels and reduced vehicle emissions resulting from the UK’s first lockdown caused pollution levels to drop by nearly 50% in some of London’s pollution hotspots. More generally though, a further study has found lockdowns have had less positive effect on air pollution than initially thought. A rise in ozone concentrations – due to wider atmospheric factors – was also found to counter some of the positive benefits of NO2 reductions.

Some solutions – Alongside the electrification of vehicles, improved detection and tracking of air pollution levels can aid effective responses to address the problem. Technologies such as Aclima’s emissions-monitoring platform, which tracks localised air quality insights, can provide communities and governments with a visual representation of urban pollution coverage.

Other efforts to reduce air pollution include natural solutions. In Seoul, wind path forests are being introduced to curb air pollution levels in the city and promote clean air circulation. Elsewhere, plans to give Paris’ Champs-Elysees a green transformation have been approved, which will include the creation of a 1.9 km-long green space comprised of tree tunnels and pedestrian zones to reduce the number of vehicles passing through by 50%.

Lateral thought from Curation – While curbing air pollution levels can reduce impacts on human health, it might be worth nothing that other effects could arise temporarily. For instance, reducing air pollution in some regions could result in warmer surface temperatures and intensified monsoons as there are fewer barriers to sunlight reaching the Earth’s surface. This, however, should not take away from the risk of larger climate consequences that will occur if current greenhouse gas levels are not significantly reduced, which would bring substantially more detrimental outcomes to human wellbeing and ecosystems.