Fact/Fiction: Is your roast dinner killing you with indoor air pollution?

How it was told

Just when you thought the red meat was the biggest health risk in your Sunday roast, guess again.

Last week, research from the HOMEChem project – a University of Texas study that tested the impact that cooking meals had on indoor air quality – hit the headlines.

Reports said that dishing up the traditional roast dinner could create fumes that were 13 times more polluting than those inhaled while taking a stroll through the centre of London.

The widely reported study pointed to tiny particles known as PM2.5s – because they are less than 2.5 micrometres – that are linked to heart disease, stroke and lung cancer, causing 30,000 premature deaths in the UK every year.

The story cooked up a storm in the Daily Mirror, which went with the headline: “Cooking Sunday roast exposes people to more toxic air than polluted city street”. The Guardian’s story also compared the indoor findings to pollution levels found in a city, in their case Delhi: “Cooking Sunday roast causes indoor pollution ‘worse than Delhi’”.

The Mail Online kept matters much closer to home: “Making a roast exposes you to more pollution that standing in central London: Cooks told to use extractor fans and open windows to disperse harmful particles”.

Health concerns were first and foremost for The Daily Telegraph with “Why your roast dinner could be killing you: Indoor pollution from cooking as bad as in city centres, say scientists”.

As for The Independent and i, they both opted to answer the question: “Why roast dinners cause more air pollution than traffic”.

But is there any meat on the bones of the story or is it all a bit half-baked?

Facts. Checked.

It is true that the readings found in the study did exceed those found in cities, but to say that they are more deadly than urban ambient pollution is misleading.

The study found that when the scientists cooked a roast, the levels of PM2.5 particles in the house rose to 200 micrograms for one hour.

“We were all surprised at the overall levels of particulate matter in the house,” said Marina Vance, the University of Colorado professor who led the research.

This is down to exposed flames on gas cookers, oil cooking on hobs and roasting meat and vegetables releasing the particles that are small enough to pass into the lungs where they can cause respiratory problems and cardiovascular disease as well as finding their way into the bloodstream.

But typically, cooking a roast dinner takes a couple of hours on a Sunday, so while it may be unhealthy, does that make it more unhealthy than living in a polluted city?

According to the World Bank, in 2017 the urban population in the UK was 83.14 per cent, which means that around 54 million people live and work in cities.

When you take into account that the average amount of time a person spends indoors in the UK – between 90 and 92 per cent of their time – that means that they spend about 14 hours outside in an average week.

The PM2.5 average in London is 13.8 micrograms at the roadside and 18 micrograms in the background as of January. That is dwarfed by the world’s most polluted city, Kanpur in India, which the World Health Organization’s Global Ambient Air Quality Database says has an average of 173 micrograms per cubic metre.

For anyone wanting to travel anywhere in that city, being exposed to pollution is unavoidable and just imagine the effects of that over time. But the advice for dealing with the potentially lethal effects of a roast? Open a window or use the extractor fan and you’ll be just fine.

Illustration: Miles Cole