How we discovered the poor state of indoor air quality in the UK

Volunteers from varied home environments and lifestyles were chosen to record all activities taking place in their house while using indoor air quality monitors placed in various rooms. These were used to record dust particles and dangerous chemicals present in the air.

The data highlighted significant concentrations of levels of PM2.5 particles (fine dust molecules). These can lead to serious health conditions such as asthma and other respiratory diseases, allergies, dementia, mental health issues and insomnia. It also revealed dangerous levels of volatile organic compounds (VOCs) in the air. These can lead to allergies, asthma, headaches, dizziness, eye and nose irritation, nausea, eczema, mental health issues, cognitive impairment and cancer.

What are safe levels?

In terms of PM2.5 the World Health Organisation (WHO) guidelines are 10 micrograms per cubic metre. A recent Breathe London survey suggests that 90 per cent of schools are exceeding this, and traffic on London roads averages 23 10 micrograms per cubic metre.

For VOCs there are no formal guidelines. In part, this is because VOCs are a group of different chemicals and definitions of exactly what to include in this group varies. It is estimated, however, that concentrations of VOCs in indoor air are two to five times greater than those in outdoor air, and sometimes may reach levels 1,000 times higher.

In Zehnder’s analysis we have used the following VOC risk classification, using parts per billion as the measure, meaning that for every billion molecules of air there is one molecule of a VOC.

• <1000 ppb is acceptable
• >1000 ppb and < 10,000 ppb has some health risk
• >10,000 ppb may produce serious health risk

It’s worth noting that these are generous averages – other commentators place the bar much lower, with levels between 50ppb and 325ppb considered acceptable.

What we found out

The research revealed that:

• The use of cleaning products, in this case beach used when bleaching the participants bathroom, can raise the levels of VOCs in the house by 25,623 per cent, from 64ppb to an extremely toxic 16,565ppb
• Carrying out washing, in this instance using a washing machine, can raise the levels of PM2.5 from 2.2 micrograms per cubic metre to 109.7 micrograms per cubic metre – that’s nearly five times more than is present on a busy London road
• Even a spot of ironing (using a water spray) can see VOC levels raise to concerning levels. They rose by 1,635 per cent, from 109ppb to 1,892ppb
• Removing and reapplying nail polish also poses significant risks to our health. This activity saw VOC levels skyrocket by 4157 per cent, from 200ppb to 8,514ppb

 What does this mean for UK homes?

With winter setting in we can expect VOC concentration in indoor air to rise higher and higher. It is believed to be three to four times higher than the VOC concentrations during the summer.

The cause of this is poor ventilation leading to low rates of air exchange between the indoor and outdoor environment as a result of tight-shut windows. It has been discovered that as many as 50 to 300 different VOCs may be present in the indoor air in which we spend 90 per cent of our time.

Some examples of these compounds include:

• Formaldehyde
• Toluene
• Benzene
• Xylene
• Perchloroethylene
• Ammonia (the most likely culprit in the nail varnishing readings we took)

In Approved Document F, UK building regulations concerning ventilation that are currently in draft proposal due for publication in 2020 and the World Health Organization (WHO) guides first published in 2010, measures are placed against different chemicals that can cause harm to health.

In terms of cleaning and household products these are widely present in, but not limited to:

• Aerosol spray products, including health, beauty and cleaning products
• Air fresheners
• Chlorine bleach
• Detergent and dishwashing liquid
• Dry cleaning chemicals
• Rug and upholstery cleaners
• Furniture and floor polish
• Oven cleaners

As part of its recent investigations the Clean Air Day campaign has referred to UK households as ‘toxic boxes’, due to the number of air pollution particles that are trapped inside. With everyday activities such as cleaning, ironing, washing clothes and applying nail varnish ready for a Saturday night, causing potentially dangerous air to breathe, it’s hard to disagree.

Our methodology

The study was conducted across five different homes, each with a different set of variables (pets, no pets, windows open, windows closed, ventilation fans and units on and off etc). Each subject had the device for five days and took a diary during that time, detailing activities and variables.

These results are part of an ongoing study: further data relating to other variables are available upon request.

The Awair air monitoring device was used for the study, placed in different rooms such as the kitchen, living room, bedroom and hall, throughout each part of the study.

Awair’s sensors are designed and tested to accurately identify the five key factors of air quality. Each sensor is strategically placed to ensure optimal airflow and consistent readings. The data was analysed using the Awair app, which produces graphs and averages for five factors: Temperature, Chemicals, PM2.5 particulates (dust), CO2 levels and humidity.