Last week, this column pointed out the air pollutants strongly associated with the transmission of Covid-19, and the death rates in highly urbanized countries around the world which have been badly hit by the pandemic.
Evidence from China and England was reported last week. This week, let us look at the evidence from scientific studies conducted in Germany, Italy and the United States.
In Germany, Bilal and colleagues from different universities in China, Pakistan, Spain and Turkey reported that moderate to high levels of fine particulate matter (PM2.5) and nitrous oxides in the air had been associated with outbreaks.
Reporting in the 2020 issue of Air Quality, Atmosphere & Health, the researchers noted that larger particulate matters in the air (PM10) had significant and adverse effects only on people already testing positive with Covid-19.
In Italy, particularly in the hard-hit cities of Milan and Florence, Simone Lolli and colleagues from the National Central University in Taoyuan (Taiwan) reported in the 2020 issue of Scientific Reports that PM2.5 air pollutants had been associated with Covid-19 transmission. However, its effect was not as strong compared to the effects of low humidity and low temperature in causing infection and virus transmission. This means that in cooler countries, air pollution is less of a worry for outbreaks and community transmission.
In the United States, fine particulate pollutants played a significant role. Xiao Wu and colleagues from Harvard University and Dana-Farber Cancer Institute found that a mere increase of one microgram PM2.5 per cubic meter of air had increased the Covid-19 death rate by eight percent. Their findings were published in the November 2020 issue of Science Advances.
However, these did not compare the effects of humidity and temperature, unlike the study conducted in Italy.
It is not the lack of vaccination that caused the surge of Covid-19 cases in major cities in the Philippines. We already know that vaccination cannot prevent infection. These findings explain why people who did not stay at home and follow safety protocols get infected because of the high levels of pollutants in these cities. Lack of filtered air-conditioned homes also causes community transmissions at home.
Therefore, apart from installing an air conditioning unit and having its filter cleaned regularly, global studies also recommended setting an ultraviolet disinfectant inside homes to help kill Sars-CoV-2 when it penetrates your physical defenses.