RSS Feed

Related Articles

Related Categories

New study finds alarming indoor CO2 levels in London

19th November 2017 Print

London’s dangerous levels of air pollution are constantly hitting the headlines. But, while the capital’s outdoor air gets plenty of publicity, a new study has found that indoor air pollution in London might be a much bigger worry. 

Currys PC World and Dyson worked alongside Professor Ian Colbeck from the School of Biological Sciences at the University of Essex to better understand the extent of indoor air pollution in London.

As an expert in indoor air quality, Professor Colbeck helped provide some insights into a study carried out with the help of four volunteers. They used air quality monitors to measure the carbon dioxide (CO2) levels in the places they visit every day, and some of the results were shocking.

London’s indoor air pollution problem

Carbon dioxide is naturally present in the air at around 400 ppm. However, all four participants consistently measured above this during the experiment:

- Almost all of the participants found consistently high levels of CO2 during their commutes, whether they were going to work or dropping their son off at day-care.

- Ana, an office worker, had the highest reading among our volunteers during their commutes, recording 2284ppm at Baker Street Station on the way to work.

Professor Colbeck warns that CO2 levels between 1000-2000 ppm can cause drowsiness, while levels above that are even more worrying. CO2 levels between 2000-5000 ppm can cause headaches, sleepiness, poor concentration, nausea and increased heart rate.

The levels of CO2 inside homes and places of work were also surprisingly high:

- Cecile, a mother and teacher who was staying at home during the school holidays, recorded a worrying 1172 ppm at home, taken after her son had gone to bed. Unfortunately, the CO2 levels stayed high into the next morning, with Cecile and her son starting the day recording levels at 770 ppm. With CO2 at high levels having such a harmful effect, the readings present a concerning situation for her family.

- In contrast, Owen, a construction worker, measured some of the lowest levels of CO2, and an average of 373.5 ppm at work busting the myth that all construction sites are polluted places to work. His readings also show promise for the impact of pollution-minimising solutions, such as ensuring good ventilation in confined spaces. Owen commented that at his workplace, and in the industry in general, they take precautions to reduce the levels of pollution that workers are exposed to.

- Interestingly, Emma, a personal trainer living in Dollis Hill, found that spending most of her working day outdoors exposed her to less pollution than when at home.

How to limit exposure to indoor air pollution

Professor Colbeck has carried out extensive research into indoor air quality and its impact on health. Here are his top tips for reducing indoor air pollution in your home:

1. Need to smoke? Do it outside.
If you need to smoke, do it as far away from your home and any open windows as possible to prevent the smoke from seeping back indoors.

2. Love your rugs? Think again.
Choose hard-surface floors for every room to help prevent allergenic or harmful particles from building up. Then just use a microfibre mop to clean the floors every week.

3. Don’t be a doormat – beware your shoes
Help prevent dirt and debris from entering your home by placing a doormat outside your front door, and introducing a no-shoes-inside policy.

4. Cook without leaving a trace
Use an extractor fan whenever you cook to protect yourself from harmful levels[1] of nitrogen dioxide (NO2) caused by gas cooking.

5. Banish condensation
Prevent condensation from creating harmful mould and damp[2] by increasing ventilation in your home. Cover boiling pots and pans, open windows, keep the kitchen door closed when cooking, and use a humidity monitor to ensure the humidity level in your home is kept between 30% and 50%.

6. Go all-natural
Limit your exposure to volatile organic compounds (VOCs) that can be hazardous to your health[3] by using products based on natural ingredients. If you do need to buy products that contain VOCs, buy just enough to use immediately so you don’t build up a stockpile.

7. Embrace the green stuff
Houseplants can help improve indoor air quality naturally and effectively. NASA[4] recommends the following plants for removing air pollutants: English ivy, philodendron, bamboo palm, peace lily and mother-in-law’s tongue.

8. Purify the air
Houseplants work particularly well when paired with an air purification system that uses activated carbon filters and a fan. An air purifier can work wonders for improving the air quality in your home by capturing even the smallest allergens and pollutants from the air.

To see the full results of the indoor air pollution study, visit