Mixed news for PM2-5

The first quarter of this year saw both good and bad news on respirable particulate matter, PM2-5. Rick Gould reports.

The good news is that levels of the harmful pollutant have fallen due to the impact of the coronavirus lockdown, due to large falls in road traffic. Levels of PM2.5 have dropped by as much at least a third in London, Birmingham, Bristol and Cardiff, and by about a quarter in Manchester.

Scientists have been exploring whether there are any links between the virus and air quality. This follows on from research published in 2003 (1) where scientists found that there is a synergistic impact of poor air quality and the SARS virus, where exposure to poor air quality significantly increased the mortality rate.

More recently, researchers at Harvard School of Public Health examined larges sets of data and found that in populations chronically exposed to poor air quality, a small increase PM2.5 leads to a large rise in the mortality rate from COVID-19 (2).

Meanwhile, in Parliament, MP's voted against the provisions in the Environment Bill to adopt the World Health Organisation's (WHO) recommended limits for ambient PM2.5, despite a commitment in the 2019 Clean Air Strategy to meet this higher standard. Few towns and cities in the UK currently meet the WHO target.

References1 Cui, Y et al (2003). Air pollution and case fatality of SARS in the People's Republic of China: an ecologic study. Environmental Health volume 2, Article number: 15 2 Xiao Wu, M.S et al (2020). Exposure to air pollution and COVID-19 mortality in the United States, https://www.eenews.net/assets/2020/04/07/document_gw_01.pdf