Heavy smog conditions are pictured in Karachi on November 14, 2018. - Rains reduced lingering air pollution across the region on November 14, but smog levels remained around 383 AQI in Karachi -- significantly higher than the recommended WHO safe levels. (Photo by RIZWAN TABASSUM / AFP) — AFP or licensors

Can poor air quality in our urban centres exacerbate mortality due to Covid-19?

Relationship between air pollution and respiratory and cardiovascular diseases can make it harder to fight Covid-19.
Published April 22, 2020

Balancing one spinning top on another isn't easy. The reason the thought is relevant here is that it provides an image that is at least a bit like trying to layer Covid-19 spread on top of models of air pollution and climate change. Yes, it is tempting to blame anything that emerges in the 21st century on environmental problems like air pollution and climate change because those are instrumental processes that we know are happening. But there are lots of other global and local scale anthropogenic changes going on around us. Putting them together is not an easy task but with enough knowledge and careful consideration, some inferences about the current and future spread of communicable diseases like Covid-19 can be made.

WHO has recognised that "people of any age who have serious underlying medical conditions are at higher risk to get critically sick from the Covid-19 virus". Among these pre-existing health conditions, few identified are cardiovascular diseases, chronic respiratory diseases like asthma, and people who are immunocompromised due to conditions like smoking, cancer etc.

These preconditions highlighted by WHO are also the conditions caused by air pollution and areas that had high levels of air pollution before the pandemic are more vulnerable to the infection in comparison to patients in cleaner parts of the world. A study conducted during the Sars epidemic in China reveals that Sars, caused by a virus genetically like Covid-19, caused high mortality in areas with poor air quality. This information about Sars encouraged researchers to find links between mortality rates and air quality. A study conducted in Italy summarises that the high mortality rate due to Covid-19 recorded in the north of the country correlates with the region's highest levels of air pollution, substantiating that pollution should be considered as an additional risk factor. Similarly, researchers at the Harvard TH Chan School of Public Health in Boston investigated the relationship between Covid-19 fatality and air pollution up to April 4 in 3,000 US counties and established that increase of only 1mg/m3 of PM2.5 related to a 15% increase in the Covid-19 death rate. "Although the epidemiology of Covid-19 is evolving," the researchers write in the study, "we have determined that there is a large overlap between causes of deaths of Covid-19 patients and the diseases that are affected by long-term exposure to fine particulate matter." Since PM2.5 exposure causes severity in cardiovascular and respiratory diseases, it also renders people at increased risk of death from Covid-19.

Separately, a study conducted in Italy showed that cities with an average number of 125 days exceeding the limits set for PM10 had an average number of infected individuals higher than 3,200 as compared to 900 infected patients when days of PM10 limit exceeding remain less than 100 (48 days on average). To minimise the risks and impact from future epidemics like Covid-19, the maximum number of days per year in which cities can exceed the limits set for PM10 or for ozone, considering their meteorological condition, is less than 50.

In 2019, Pakistan ranked second most polluted country in the world with an annual PM2.5 average of 65.8 µg/m³

Pakistan is considered the sixth most populous country in the world and has 36.4% of its population living in urban areas. The country also has the highest urbanisation rate in all of South Asia. As a result of this proliferation, population density has increased and this has negatively impacted air quality, particularly in the country's urban regions. According to World Air Quality Report 2019, several cities in Pakistan, including Lahore, Karachi, Peshawar, and Faisalabad rank prominently among the most polluted cities globally. And in these cities, the pollution coupled with population density and overburdened healthcare structures severely impact public health. These urban centres also observe 10 times more annual hours in the highest US AQI bracket (250.4μg/ m3) than in the US AQI bracket that meets the WHO's annual target (<10μg/m3).

Source: World Air Quality Report 2019
Source: World Air Quality Report 2019

Air pollution has the highest contribution to the environmental burden of disease in Pakistan and is responsible for nearly 22% of premature deaths in the country. The World Bank estimates that 9% of the country's annual deaths are because of air pollution. The loss equivalent to 2% and 2.5% of GDP annually in 2016 has been accounted for the costs of illnesses and premature deaths from ambient air pollution and household air pollution respectively. These alarming air quality statistics are enough to depict that air pollution will likely exacerbate the mortality rate due to Covid-19.

The proven relationship between air pollution and respiratory and cardiovascular diseases can worsen the situation and make it harder to fight the disease caused by the novel Coronavirus. The concentration of PM2.5 in air at 10 µg/ m3 is rendered safe as per WHO's Air Quality Guidelines. Since the major culprit in this case is transportation, the problem of air pollution is worse in urban centres like Karachi and Lahore; these cities are already hit hard by Covid-19 with over 900 confirmed cases in each and the numbers of those infected and getting sick because of the virus increasing on a daily basis.

But, is there a green lining here?

Even if the crisis is to be taken as an opportunity for growth, it comes with the caution of not glorifying the suffering that has been caused by Covid-19. Any green lining that comes out of this will depend upon how we paint it together. The convoluted nature of causes of climate change and air pollution related illnesses provides the opportunity to deal with both problems simultaneously. The interventions designed to mitigate climate change will also help manage the air quality and vice versa. And paradoxically, lockdowns due to the Covid-19 pandemic can help decrease the total number of deaths during this crisis by drastically decreasing the number of fatalities due to air pollution. Moreover, in addition to the reduction in the number of deaths due to air pollution, the decrease in air pollution itself could also have positive benefits in reducing preventable non-communicable diseases.

If action is taken to control air pollution, it will limit greenhouse gas emissions. Similarly, phasing out fossil fuel from the energy sector will not only solve the problem of air pollution but also climate change. The control of additional activities like agricultural waste burning, open waste dumping, solid waste burning, and emissions from coolants such as Hydrofluorocarbons (HFCs) will guarantee that anticipated benefits are realised. Taking up an integrated approach now to cater to both problems will amplify the benefits for Pakistan in building resilience in our environmental and health systems to face health crises like Covid-19 more effectively in the future.

The investigations on Covid-19 and air quality also highlight the need to update existing air pollution regulations and enforce new and stricter ones to prepare for the time when the lockdown is over and particle concentrations begin to increase again. This pandemic has not only shown us the importance of efficient and functioning health systems but also the value of air quality as vital in building resilience for any country.

A lot of money will be reinvested to stabilise the economy, which can be planned in a way to encourage industries to invest in low-carbon technology and move towards net zero emissions. Given the link between air pollution and Covid-19, governments should take serious measures to combat climate change in order to reduce air pollution and make the population less vulnerable.

Last month, the government announced a PKR 1.13 trillion relief package, which includes Rs 100 billion financial support to SMEs and Rs 100 billion in support to refinance investment in new manufacturing plants and machinery. This offers an opportunity for us to move towards the green economy and invest in low-carbon technology. It also presents an opportunity to the Government of Pakistan to develop policies and mechanisms through the lens of Covid-19 and climate change mitigation to be more prepared in the future to better manage environmental and health risks.

"There is a need to pragmatically mainstream 'green economy' in the country for economic stimulus in the post-Covid-19 world. With our failure to institutionalise the opportunities around green jobs, green industry, green transport and green agriculture through drastic reduction in the use of toxic materials, the idea of cultivating a 'green economy' will remain a romantic slogan and instead of triggering required policy and action changes. It is only these intrinsic and nature friendly transformations that can usher a safer and more resilient development in Pakistan," says ​​​Secretary Ministry of Climate Change Naheed Shah Durrani.

Investing more in renewable energy, electric vehicles, and low-carbon technologies in the future will not only do well to fight climate change but will also help prepare countries to deal with such epidemics and pandemics in the future in this highly interlinked and complex symbiosis.

Header photo by AFP