You are more exposed to PM2.5 cooking an omelette in your kitchen than standing on an average London roadside, a study has claimed.
Ventilation firm Zehnder UK asked five volunteers to place an indoor air quality monitor inside their home for five days, writing down their activities as well as potential variables such as whether their window was open or not.
One volunteer’s home recorded consistently low levels of PM2.5 throughout the five days but experienced a peak of 68µg/m³ when they cooked an omelette and used a grill.
This is almost three times the average level of 23µg/m³ recorded in London by the roadside.
One volunteer was a smoker who was joined by friends to smoke throughout an evening. Over a period of two hours, the PM2.5 level jumped from a safe level of 1.3µg/m³ to 839µg/m³.
A dangerous level of PM2.5 is considered to be anything over 76µg/m³.
Another volunteer recorded a large spike of 85 µg/m³ at around 7am when his wife was using hairspray as she got ready for work.
Rupert Kazlauciunas, technical product manager at Zehnder UK said indoor air quality is ‘dangerously overlooked’.
‘We spend as much as 90% of our time indoors – yet mention air quality and our thoughts immediately turn to large lorries pumping fumes, cars clogging our roads or factories belching out smoke,’ he said.
‘The chemicals and particles we breathe in our homes and workplaces actually pose a far more dangerous threat to our health than most people realise.
‘Smoking, perhaps, is not a huge surprise, but cooking, using cosmetics and even just having pets or vacuuming our carpets can raise dust particles to harmful levels.’
The dangers of indoor air pollution have been highlighted in several recent studies.
Global Action Plan asked the National Air Quality Testing Services (NAQTS) to conduct four experiments with four families in different UK locations in April and May 2019.
Each study monitored the level of ultrafine air pollution particles over a 24-hour period inside and outside the four families’ properties, which found that ultrafine particle pollution levels were on average 3.5 times higher inside than outside, peaking at 560 times outdoor air pollution.
Researchers said this is due to a combination of indoor activities such as cooking or burning wood alongside outdoor pollution from transport, which travels inside, creating a build-up of pollution inside the home, with pollution peaks taking longer than outdoors to disperse.
Ultrafine particles have the potential to have greater health impacts than PM10 or PM2.5 pollutants because they are smaller and evidence suggests they can be more easily absorbed into the body.
Another study said UK households are experiencing dangerous levels of indoor air pollution due to ‘significant’ levels of formaldehyde, a human carcinogen that is found in adhesives in wood products such as MDF, carpets, furniture, paints and varnishes.