Covid-19: what you need to know today

On Wednesday night, as fog shrouded Delhi, it was clear that Thursday would be bad. Sure enough, the capital woke up to adequate smog on Thursday (the smog made things warmer due to the premature cold that set in on the northern plains). As this column, the 199th installment of what started on March 19, is being written late Thursday morning, the light has improved, the sun is out, but the air quality is still poor according to the Sameer app. (AQI 472). That AQI level corresponds to what is called “severe” air quality. It is nothing new for Delhi of course, but it is still bad and is likely to get worse.

At this stage, I would like to reassure regular readers of this column whose eyes are turning to the headline that this is still a daily dispatch on what you need to know about Covid-19 today, not what you need to know. about the bad air of Delhi today. There are two reasons why I started contamination.

The first is that Delhi’s first official “severe” AQI day this season is not timed at the right time – it comes shortly after the respected journal Science Advances published an article titled “Air Pollution and Mortality from Covid-19. in the United States: strengths and limitations of a regression analysis “.

According to Francesca Dominici of Harvard University, and other authors, sustained exposure to bad air, specifically PM 2.5 particles, with a diameter less than 2.5 microns, has a direct correlation with death rates from Covid-19 . This is the point where deniers are likely wondering how researchers managed to reach this conclusion given the current state of Covid-19, and the fact that the effects of exposure to polluted air are, as are the effects of smoking. probably established over time. The researchers solved this by using an ecological regression analysis of “historical exposure to PM 2.5” and death rates from Covid-19.

Stripped of jargon, this meant taking average concentrations of PM 2.5 over a long period of time (the researchers took daily data for 16 years) and saw the impact this has on Covid-19 death rates in US counties. They used what is called a negative binomial mixed model for this. They also adjusted their analysis for other factors, including population density, poverty, education, and climate. While they admit that their study cannot be “adjusted for risk factors at the individual level,” they suggest that it can be improved by incorporating data at the “individual level.”

The study found that an increase of one microgram per cubic meter “in the long-term average of PM 2.5 is associated with a statistically significant increase of 11% in the country’s Covid-19 death rate.”

That’s bad news for Delhi, where Covid-19 cases are on the rise (again). There are other studies, including some peer-reviewed from Europe that previously established the link between air pollution and Covid-19 mortality, but none followed a methodology as rigorous as Harvard’s. And none established such a strong correlation.

Without a doubt, the study only seeks to establish a link between bad air and mortality from Covid-19; did not study the links between the incidence of the disease and bad air, which means that there is no basis to claim that there is a relationship between Delhi’s air pollution and the increase in the number of cases (although there may well be one) .

The second reason is that there is a great similarity in the way India and Indians have dealt with the two health crises, air pollution and Covid-19.

Understanding and responding to both requires a fundamental belief and respect for science and data, something that has not always been obvious. And the successful management of both requires, at least in part, a change in behavior, where, again, everyone involved (from the administrations to all of us, the people) have found themselves deficient.