Study says air pollution, more wind could fan spread of virus

Scientists are now raising concerns that air pollution and calm air could aid the spread of Covid-19.

A research in Bergamo Province, Italy, found coronavirus in particles of polluted air in preliminary work published in April in MedRxiv, a pre-print server for health sciences.

The researchers from the University of Bologna wrote: “In previous communications, we have hypothesised the possibility that Sars-CoV-2 virus could be present on particulate matter (PM) during the spreading of the infection, consistently with evidence already available for other viruses.”

Samples were collected from the industrial area of the province over a period of three weeks between February and March when Covid-19 visited untold misery in the country. The researchers said they confirmed the presence of the virus in the air.

The researchers chose Bergamo due to its heavily industrialised nature and the fact that Covid-19 had severe impact in Lombardy and Po Valley where the city is situated. Four in every five coronavirus deaths in Italy were from four regions of Po Valley and the region also accounted for 65 per cent of ICU admissions in the country.  

“I am a scientist and I am worried when I don’t know. If we know, we can find a solution. But if we don’t know, we can only suffer the consequences,” said Leonardo Setti of the University of Bologna, who led the study.

This raises a critical question on whether air pollution can exacerbate cases of Covid-19. An earlier study by Harvard School of Public Health linked increased particulate nature to higher death rates from the virus.

“This is the first preliminary evidence that Sars-CoV-2 RNA can be present on outdoor particulate matter (PM), thus suggesting that, in conditions of atmospheric stability and high concentrations of PM, Sars-CoV-2 could create clusters with outdoor PM and – by reducing their diffusion coefficient – enhance the persistence of the virus in the atmosphere,” says the study.

The study, however, noted further research should be done to find out whether presence of coronavirus in air pollution could increase infections.

Another research in Northern Italy concluded that areas with higher particulate matter concentration over many days are likely to have more infections and fatalities. The working paper by National Research Council of Italy noted that there are two aspects of infections – air pollution-to-human and human-to-human.

The research looked at coastal versus hinterland cities as well as windy versus non windy areas. Findings were that there were more infections in windy cities compared to less windy ones.

“Cities that average number of 125 days exceeding the limits set for PM10, last year, have an average number of infected individual higher than 3,200 units, whereas cities having less than 100 days (average number of 48 days) exceeding the limits set for PM10, have an average number of about 900 infected individuals,” reads the study.

The paper suggests that to minimise future epidemics similar to coronavirus, the maximum number of days per year in which cities can exceed the limits set for particulate matter or for ozone, considering their meteorological condition, is less than 50 days.

Critical threshold

Once this critical threshold is passed, the analytical output suggests that environmental inconsistencies because of the combination between air pollution and meteorological conditions - with high moisture, low wind speed and fog – trigger increased infections with damages for health of population, economy and society.

This is one of the findings that makes a strong case for fumigation in the midst of the coronavirus as well as a new outlook towards greener cities.

The air quality in Nairobi, according to IQ Air, which measures air quality, is at 38 with particulate matter (PM) at 2.5. This could have been aided by the cessation of movement and stay-at-home orders for the past six weeks.

With the world having slowed down, industries shut and travel reduced, carbon emissions have drastically dropped, and most cities can breathe again.

This reality brings to the fore the question of whether the world is looking at a greener future.