Short-term home radon tests faulty 99% of the time, Calgary study finds
University of Calgary found 90-day testing gives more reliable results

Short-term radon test kits are not an effective way to find out if your home has unsafe levels of the dangerous gas, a new study says.
The University of Calgary-led research published this week found that the only reliable way to measure exposure to radon gas is a long-term testing kit, which takes readings within the home for 90 or more days.
"Radon gas levels can fluctuate wildly day-to-day," says Dr. Aaron Goodarzi, who is with the university's Cumming School of Medicine and also teaches biochemistry and molecular biology.
"Short-term tests can give a false sense of alarm, or worse, a false sense of security as they cannot precisely predict long-term exposure."
The researchers placed two test kits — a five-day and 90-day — in the same homes. Tests were done during the summer and winter months.
The results showed that the short-term kits were imprecise up to 99 per cent of the time when compared to a long-term test.
A 2017 study found that levels are dangerously high in one of eight homes in the Calgary area. The new study also shows the Prairies have the second-highest radon exposed population on Earth.
Health Canada lists radon as the No. 1 cause of lung cancer in non-smokers. It's estimated that radon kills 3,000 Canadians a year.
The Canadian guideline for radon in indoor air is 200 becquerels per cubic metre (200 Bq/m3).
supported by the Alberta Real Estate Foundation, Alberta Cancer Foundation, Health Canada, the Canadian Institutes of Health Research and the Robson DNA Science Centre Fund at the Charbonneau Cancer Institute.