Because of the urgent need to share information relating to the pandemic, the researchers have published their report on MedRXiv. It has not yet been peer-reviewed. However, the preliminary data is supported by data in other countries.
While the initial symptoms of COVID-19 include fever but do not always include breathing difficulties, some patients go on to develop very serious respiratory problems. Although most patients only experience mild illness, around a quarter of hospital-admitted cases require intensive care treatment because of viral pneumonia with respiratory complications. While research suggests that COVID-19 likely stems from an overactive immune response, it is not clear why some patients are at greater risk of severe disease.
Previous studies suggested that individuals over the age of 60 or with underlying health conditions, including cardiovascular disease, diabetes, chronic respiratory disease and cancer, are at highest risk of severe disease or death. Long-term exposure to air pollutants, including nitrogen oxides and ground level ozone from car exhaust fumes or burning fossil fuels, is a known risk factor for these health conditions. Such pollutants can also cause a persistent inflammatory response and increase the risk of infection by viruses that target the respiratory tract.
In this new study, researchers at the MRC Toxicology Unit at the University of Cambridge report an association between certain air pollutants and COVID-19 in England.
The team analysed the data on total COVID-19 cases and deaths, against the levels of three major air pollutants, collected between the years 2018 and 2019, when no COVID-19 case was reported. Their study used publicly available data from seven regions in England, where a minimum of 2,000 SARS-CoV-2 infections and 200 deaths are reported in the period from February to the 8 April 2020.
The largest number of COVID-19 deaths in England occurred across London and the Midlands, reflecting the geographical distribution of COVID-19 related cases. Previous studies have shown that the annual average of nitrogen dioxide concentrations are largest in these two regions.
Image: Oncoming Traffic
Credit: Mike Knell
Reproduced courtesy of the University of Cambridge