People who do not ventilate their homes properly expose themselves to harmful levels of pollutants, according to experts from the Glasgow School of Art.
Specialists at the school's Mackintosh Environmental Research Unit (MEARU) said modern homes were being built to be airtight.
This causes a build-up of harmful chemicals and moisture if householders do not open windows or vents.
The unit has made a series of recommendations to reduce pollutants.
Prof Tim Sharpe, head of the MEARU, said: "Poor indoor air quality, particularly in bedrooms, is hard for people to detect.
"There are clear links between poor ventilation and ill-health so people need to be aware of the build up of CO2 and other pollutants in their homes and their potential impact on health."
The MEARU conducted a survey of 200 homes which were constructed to modern, airtight standards. It found that most householders kept trickle vents closed, and bedroom windows closed at night.
Margaret and John Trainer, from East Renfrewshire, were given an instruction manual for their new home which explained how to ventilate it, but they found the document hard going.
"It was too technical," said Mrs Trainer.
"It was a huge folder and it just went into the drawer and that's where it stayed. It was designed for someone who was mechanical. It wasn't any use to me."
Levels of pollutants can be five times higher indoors than outdoors and when vents and windows are kept closed, the chemicals have nowhere to go.
Common pollutants include carbon dioxide, volatile organic compounds from carpets and soft furnishings, formaldehyde in MDF and plywood, and phthalates which are used in plastics.
These various chemicals cause eye and skin irritation, damage the central nervous system and have been linked to cancer.
High levels of moisture encourages growth of dust mites - bad news if you have asthma, hay fever or allergies. It also encourages mould spores in the air which causes lung infections in people with weak immune systems
Experts at the MEARU have been working with the Hanover Housing Association in Scotland, which built Mr and Mrs Trainer's house.
Kenneth Shepherd, development officer at Hanover Housing Association, said: "Working with Professor Sharpe and his team has been an eye-opener.
"Many of our residents have lived in old, draughty houses and are delighted to have moved into new, well-insulated properties.
"Unfortunately, few of us were aware of the issue of indoor air quality. Going forward, all our residents will be provided with full information on how to monitor the air quality and the best way to keep their new properties ventilated."
Simple steps experts recommend include:
- Keeping trickle vents or windows open when cooking or showering
- Increasing ventilation when cleaning
- Open windows at night
- Dry laundry near an open window
- Make sure you understand how the ventilation system of your property works
Mr and Mrs Trainer said they now understood the importance of keeping the air circulating in their new home.
"We keep the vents over the windows open all the time now", said Mrs Trainer.
"We open the windows and don't put anything over the radiators, and dry laundry outdoors."