Carleton University’s Paul Villeneuve and McGill University’s Mark Goldberg have published new research calling into question reported links between air pollution and mortality from COVID-19.
Their paper, Methodological considerations for epidemiological studies of air pollution and the SARS and COVID-19 coronavirus outbreaks, was recently published in the journal of Environmental Health Perspectives.
“We feel strongly that there is no public benefit to conducting these analyses in the midst of an active pandemic,” said Villeneuve, a professor in the School of Mathematics and Statistics. “It is already well established that air pollution is a human health hazard, and we cannot envision any additional value that these studies provide. Many of these studies have not undergone the scrutiny of peer review and deflect from the increased rates of infection and health consequences due to problems of social and income disparities, overcrowding and other societal issues.”
This researchers are responding to a number of papers claiming to show that mortality rates from COVID-19 increase in areas with higher concentrations of various types of air pollution, mostly fine particulates. Many of these studies were posted on various web pages and have not been published in peer-reviewed journals. Despite this, mainstream media and American presidential candidates have commented on the research and tied it to their electoral platforms.
Goldberg indicated that “there is overwhelming evidence from around the world that disadvantaged people, those lacking health insurance or living in crowded homes, have a greater susceptibility for both contracting and dying from COVID-19. They often live in areas in which air pollution is higher than in wealthier areas, and a failing of these studies is not being able to account for this.”
The researchers reference a notable unpublished paper that came out of the Harvard T.H. Chan School of Public Health. On April 4, 2020, the New York Times reported scientists at Harvard had uncovered a link between fine particulate air pollution and an increased death rate from COVID-19. This study has yet to be published but has been referenced many times in the media. The authors of this paper originally reported that people living in an area with only a slight increase in exposure to fine particulate pollution (1 µg/m3) were 15 per cent more likely to die. Less than a month later, the investigators provided an updated risk estimate of eight per cent. Similarly to other studies of this topic, the paper has not yet been scrutinized by other experts in the field to assess the quality of the research and the validity of the results.
When Villeneuve and Goldberg examined the research about the role of air pollution on SARS or COVID-19 mortality, they found that all of the studies had serious shortcomings. Most of the studies used an ecological study design. They point out that ecological studies do not use data at an individual level, and they are not well regarded in epidemiology because they have many limitations that prevent them from providing insight on cause and effect relationships. In addition, the studies under-reported deaths from COVID-19, they have not considered differences in socio-economic status or race, they have not adequately accounted for regional differences in behaviours such as wearing masks and physical distancing, and that COVID-19 cases and deaths occur in clusters of vulnerable populations.
Villeneuve and Goldberg contend that given the limitations of currently available data, epidemiological studies are not yet able to assess whether air pollution increases the risk of dying from COVID-19.
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