Talk about air pollution, and it’s likely you’ll think of car emissions and polluted streets. But we spend 90% of our lives indoors, and the odourless and unseen gases, chemicals and small particles in the air, could literally make you sick.
Worse still, the products you’re using to mask the bad stuff – the lemon and pine you associate with cleaning products – could actually be the bad stuff.
Some people are more susceptible to the effects of indoor pollutants too – for example, if you suffer from asthma, are sensitive to allergens indoors or have heart and lung disease.
Looking for air purifiers? We’ve tested 10 models to see how well they remove pollen, dust and smoke from the atmosphere.
Indoor pollution put to the test
So, where’s the evidence of indoor pollution? We sent lab technicians to three ordinary semis: a supposedly ‘draughty’ Victorian one; a 1950s house made airtight with improvements such as double glazing and cavity wall insulation; and a new-build.
We wanted to see how much pollution was generated before and after bursts of common activities in kitchens, bathrooms, living-rooms and bedrooms. For example, when we vacuumed, did the cleaning, used air-fresheners and scented candles, cooked a fry-up and burned the toast.
We discovered surprisingly high levels of pollutants with potential long-term health effects in all the test houses.
For example, we found very high levels of volatile organic compounds (or VOCs) in every room we tested. Results were as much as 34 times the UK Building Regulations recommended maximum level – although measured over a busy 30 minutes, not 24 hours.
This was after activities including burning candles and using plug-in air fresheners, scented washing powder and toiletries such as antiperspirant and perfume.
What are VOCs?
VOCs are chemicals found in a wide variety of materials in the home and from outdoors, that can evaporate into the air at room temperature, producing vapours that we inhale.
VOCs (especially terpenes including limonene and pinene) can combine with ozone from outside air, particularly during hot weather, to form gases including formaldehyde. This is a breathing irritant that can cause sensitisation reactions, and – at very high levels – is carcinogenic.
We also saw very high increases in particulate matter – tiny particles that can enter your lungs, potentially causing serious health problems over time – in all our test-house kitchens.
How you can breathe easy
So what does this mean for you? Well, this shouldn’t make you anxious about every scented candle you burn, or open fire you light. This is about the longer-term view.
In workplaces, employers are required to provide ventilation for adequate fresh air. Inside our own homes however, the quality of the air is in our own hands, and it’s all about controlling sources of pollution and maximising ventilation.
Choose products and activities that will minimise pollution in the first place, ventilate before and after polluting activities such as cooking, vacuuming and using toiletries. Keep trickle vents open, use extractor fans and don’t block air bricks.
Are you concerned about indoor air pollution? What do you do to keep your home ventilated?