Interventions to reduce air pollution could have a significant effect on reducing the impact of COVID as well as other respiratory infections in local communities, new evidence suggests.
A study based on data from Belgium found that on average hospital stays due to COVID-19 were significantly longer when levels of particulate matter and black carbon were higher.
The team recruited 328 patients hospitalised with COVID-19 and determined previous exposure to air pollution as well as accumulation of black carbon particles in the blood.
Results, published in The European Respiratory Journal, clearly showed a link between both long-term and short-term exposure to PM2.5, PM10 and NO2 and COVID-19 severity (as shown by duration of hospitalisation).
According to the data, an interquartile increase in exposure in the week before hospital admission resulted in increased duration of stay – PM2.5 +4.13 days, PM10 +4.04 days, NO2 +4.54 days – independent of co-morbidities.
A similar impact on hospital duration was also observed with long-term NO2 and black carbon exposure (+4.39 days and +3.48 days, respectively).
“The public health and clinical significance of our findings should not be understated, as we showed that the effect magnitude of an IQR increase in long-term air pollution (e.g. an increase in NO2 by 4.16 µg·m−3) on the duration of hospitalisation was roughly equivalent to the effect on hospitalisation of a 10-year increase in age”, the researchers noted.
The data analysis also revealed that the odds of admission to intensive care were also significantly associated with higher blood levels of black carbon and long-term exposure to air pollutants.
There were key study limitations, including a limited sample size, but the findings clearly show that exposure to air pollutants “at relatively low levels has a significant impact on disease severity and progression for COVID-19 patients,” the authors concluded.
“These findings reinforce the existing call for action to reduce air pollution levels in order to limit the burden of COVID-19 and improve respiratory health worldwide”.