Cooking on fire linked to higher Covid-19 death rate, study finds

The air is cleaner with a third of the global population on lockdown, but South Africans who use solid fuel to cook and heat their homes could face a higher Covid-19 death rate.

Solid fuels, including charcoal and wood, produce high levels of solid and liquid particles, and a Harvard University study has found that higher levels of microscopic particles were associated with higher death rates from Covid-19.

Particles less than 2.5 micrometres in diameter — described by scientists as PM2.5 — are especially dangerous because they can make their way into the deepest part of the lungs and the bloodstream.

“The findings are particularly important for hospitals in poor neighbourhoods and communities of colour as they tend to be exposed to higher levels of air pollution than affluent white communities,” said lead author Prof Francesca Dominici.

Household air pollution already kills 7,600 South Africans annually, according to a Southern African Development Community report on renewable energy and efficiency.

Health minister Zweli Mkhize said on Saturday that chronic pulmonary disease, which is caused mainly by smoking but also by air pollution, was one of the underlying conditions in some of the seriously ill Covid-19 patients who had been hospitalised.  

Johanna von Holdt, an environmental and geographical scientist at the University of Cape Town, said global air pollution was decreasing markedly due to lower traffic volumes and power generation.

However, “it is a question of spatial distribution and the sources of pollutants. Many of our low-income communities in SA are reliant on solid (‘dirty’) fuels for cooking and heating.”

During lockdown, said Von Holdt, individuals’ exposure to these pollutants could increase with “people spending longer hours at home, including in areas with unpaved roads with dust emitted from this source as well”.

Leanne Jansen, 26, is one of many people who cannot turn back the clock on decades of smoke inhalation in shacks and small houses. The tin walls of the shack where she looks after her two younger siblings are black from years of indoor cooking and heating with “dirty” fuels.

“It affects our lungs, especially the two younger ones who get sick from the smoke,” she said.

According to the SA Institute for Race Relations, the danger of household air pollution is often overshadowed by the menace of pollution from mining and factories.

“While this scrutiny is not wrong, it loses sight of a problem that is not only more prevalent but much more difficult to solve, and that’s indoor air pollution,” it said in a report.

“The burden falls most heavily on the black population. Low indoor air quality affects 24% of black households, 9% of coloured households and only 1% of white or Indian households.”

Another study on air pollution and Covid-19 found a correlation between levels of nitrogen dioxide — a fossil fuel pollutant — and Covid-19 mortality rates.

German researcher Yaron Ogen mapped nitrogen dioxide levels at a regional level in Italy, Spain, Germany and France and compared them to Covid-19 deaths. “Long-term exposure to air pollution could be an important contributor to high fatality rates,” he concluded.

“Since the novel coronavirus also affects the respiratory tract, it is reasonable to assume that there might be a correlation between air pollution and the number of deaths from Covid-19.”

Though SA has a low death rate compared to other countries in the pandemic, the long-term prognosis is not yet apparent.

A 2017 study found that air pollution from SA’s coal-fired power stations kills more than 2,200 people annually and causes thousands of cases of bronchitis and asthma.