Environmental pollution increases the severity and mortality of COVID-19

During the first wave of the pandemic, the clinical data of 2,112 patients admitted to fifteen hospitals in Catalonia were analyzed and compared with the PM₁₀ levels recorded by the monitors of the Air Pollution Surveillance and Forecasting Network (Catalan government) in the cities where the hospitals were located from 2014 until the onset of the pandemic. It was concluded that COVID was more severe and lethal in people living in areas with a PM₁₀ concentration above the WHO limit. It was also found that when an individual is infected with SARS-CoV-2, the course of the disease is determined more by chronic exposure to PM₁₀ than other conditions, such as diabetes, hypertension, or hypercholesterolemia, which had become widely recognized risk factors for predicting the severity of infection through a retrospective study applying mathematical models. Finally, an increase of 1 µg/m³ in chronic PM₁₀ exposure was estimated to lead to a 3% increase in the number of patients with a severe case of COVID-19, which can result in more deaths.

The results of this study have had a significant effect on the care provided to people infected with SARS-CoV-2, a disease that has proved to have a wide range of symptoms and a somewhat unpredictable prognosis. To date, health care providers have relied solely on medical history to predict how patients will progress. Now, however, this study has shown the importance of environmental health and “provides scientific evidence that, when treating patients with COVID-19, the medical community needs to take heed of chronic exposure to toxic environmental pollutants, such as airborne particles, if the advance of  the disease is to be properly predicted," explains Montse Marquès, the first author of the research. The study paves the way to investigating the role of contamination in other respiratory viruses, such as influenza, and is a reminder that the PM₁₀ thresholds set by the WHO and global legislators need to be reviewed and updated to protect the health of the population.

The research group that took part in this study believes that the environmental concentrations of PM₁₀ need to be reduced, especially in those places where they are above established limits, so that the severity and mortality of COVID-19, and possibly other respiratory infections, can also be reduced.

The TecnATox group, led by Professor Josep L. Domingo, is a world leader in the field of toxicology and environmental health. In this research, it has worked in collaboration with the Uvasmet group, also from the URV, the IISPV and the STACOV-XULA network.