Are gas cookers bad for you? Scientists say they’re sending 40,000 Europeans to early graves a year

The new study expands our understanding of the likely extent of the human health costs of gas cooking.

Gas cookers are contributing to the early deaths of around 40,000 Europeans a year, the first scientific study of its kind has concluded.

For almost 50 years, the world has been aware of the dangers of nitrogen dioxide (NO2) emitted by gas cookers. Now researchers at the University Jaume I’s School of Health Sciences in Spain have estimated the annual death toll by linking existing health studies to NO2 readings at European homes.

They found that in 14 European countries, hazardous conditions are created inside the average home as the fumes from gas cookers combine with background pollution to break World Health Organisation (WHO) guidelines.

“Way back in 1978, we first learned that NO2 pollution is many times greater in kitchens using gas than electric cookers. But only now are we able to put a number on the amount of lives being cut short,” says lead author of the new study, Dr Juana Maria Delgado-Saborit.

“The extent of the problem is far worse than we thought, with our modelling suggesting that the average home across half of Europe breaks WHO limits. Outdoor air pollution lays the foundation for those breaches, but it is gas cookers that push homes into the danger zone.”

Which European countries are most at risk from gas cookers?

Around one-third of European homes cook with gas, and it’s these dwellings that tend to have the highest levels of NO2.

Italy, Poland, Romania, France and the UK suffer the highest share of gas cooker-fuelled premature deaths. Pollution is worst in homes with poor ventilation and those that spend longer cooking.

Indoor air quality is a serious health issue because Europeans spend almost all their time inside and buildings get less fresh air as houses are designed to be more airtight.

Gas stoves have also been found to leak methane, a potent greenhouse gas, even when they’re switched off.

As for outside pollution, NASA has recorded significant drops in NO2 pollution over European cities in recent decades thanks to EU vehicle emission rules and vehicle technology. But background pollution remains a major contributor to the hazardous levels found by the new study.

How did the researchers calculate gas cooker pollution deaths?

This study may be a significant breakthrough in our understanding of the human health costs of gas cooking.

Researchers used dozens of health studies that had established likely risk rates of asthma and premature deaths caused by a given level of NO2.

Previous studies could not apply risk rates to the real world until last year, when Dutch researchers took extensive NO2 measurements in and outside homes in multiple European countries to produce the most accurate snapshot yet of indoor pollution from gas cookers.

The university used government datasets to scale up these findings to produce regional maps of indoor NO2 pollution from stoves. These allowed researchers to calculate the first scientific estimates of premature deaths and child asthma cases from NO2 in Europe.

The true human cost of gas cooker pollution is likely significantly higher, however.

A lack of data meant the researchers had to exclude some pollution impacts that may also contribute to higher rates of death and asthma. And they focused only on NO2 pollution because it is well-studied by epidemiologists.

Other harmful pollutants created by burning gas include carbon monoxide, benzene, formaldehyde and particulate matter. The researchers say they lacked the data needed to accurately predict the impact of these pollutants.

Using a less precise method, they estimate that gas cookers cause roughly 367,000 asthma cases in children and 726,000 in all age groups including these other pollutants, excluding carbon monoxide which has no known connection to asthma.

How can we tackle gas cooker pollution?

The EU has no indoor air quality standards and its legislative tools for tackling the problem are patchy, according to the European Public Health Alliance (EPHA).

The bloc is due to propose updated rules for gas cookers later this year and has been considering pollution restrictions - including for NO2.

EPHA is urging Brussels to rapidly phase out gas cookers through emissions limits, alongside introducing financial incentives to switch to cleaner cookers.

“For too long it has been easy to dismiss the dangers of gas cookers,” says EPHA policy manager for global public health Sara Bertucci. “Like cigarettes, people didn’t think much of the health impacts and like cigarettes, gas cookers are a little fire that fills our home with pollution.”

Just as governments helped wean citizens off cigarettes, EPHA argues they should also help us quit gas.

The alliance also wants to see mandatory consumer labels on cookers to signal pollution risks, paired with public education campaigns on the risks of burning fuels indoors.