There's nothing quite like a Sunday roast, but new research claims cooking a leg of lamb and roasting potatoes can create pollution levels in your kitchen significantly higher than those found on busy city streets.

At the largest gathering for scientists in the world, it was revealed after cooking a roast, pollution levels in one's kitchen can read up to 13 times higher than in a central London traffic bottleneck.

And the traditional dinner gives off tiny pollutants known as PM2.5 particles, which are so small they can embed in the lungs and potentially invade the bloodstream.

The research, undertaken in the US, revealed roasting a traditional Thanksgiving turkey could elicit levels of pollution that exceed the World Health Organization safe zone for PM2.5 particulates of 10 m/cm.


Experiment leader, Professor Marina Vance, of the University of Colorado Boulder, said: "We were all surprised at the overall levels of particulate matter in the house. It compares to a very polluted city."

The team explained it happens as a result of the chargrill effect when roasting vegetables. Pollution levels recorded from Brussels sprouts were particularly bad, due to the rapid blackening that occurs in roasting.

Scientists recommended a less tasty alternative: boiling meat and vegetables.

"The joke we've been telling ourselves as scientists is boil everything, avoid roasting, but it's too delicious," said Professor Vance.

The experiment was conducted in a three-bedroom house, where a series of meals were cooked and pollution levels were measured with indoor and outdoor monitors.

One of the meals trialled was a Thanksgiving dinner which included roasted turkey and Brussels sprouts, accompanied by boiled sweet potatoes, bread stuffing and cranberry sauce.

The indoor and outdoor levels were recorded and PM2.5 levels in the house rose to 200 m/cm for one hour. That's more than the 143 m/cm average recorded in Delhi, listed as the sixth most polluted city.

"We know that inhaling particles, regardless of what they're made of, is detrimental to health," explained Professor Vance. "Is it equally bad as inhaling exhaust from vehicle emissions? That we don't know that yet."

The findings, shared at the American Association for the Advancement of Science annual meeting in Washington DC, were part of a wider study investigating the dangers of common household activities for indoor pollution.

They revealed evidence that chemicals involved in products such as shampoo, perfume and other cleaning solutions, also contribute to a toxic indoor atmosphere. This escapes outside and contributes more global atmospheric air pollution than cars and heavy vehicles do.

"Many traditional sources like fossil fuel-burning vehicles have become much cleaner than they used to be," explained Professor Joost de Gouw, from the Cooperative Institute for Research in Environmental Sciences. "Compounds like alcohols and ketones that originate from the home are very sparse."

Scientists suggest boiling food rather than roasting it to create a healthier internal atmosphere. Photo / Getty Images
Scientists suggest boiling food rather than roasting it to create a healthier internal atmosphere. Photo / Getty Images