Radon in the workplace

A 2012 Health Canada study showed that the radon concentration in almost 25% of homes measured in New Brunswick exceeded the recommended concentration.

It is expected that radon exposure could be an issue in some workplaces. The map of New Brunswick below provides an overview of Health Canada’s test results for our province.

While some areas of the province were found to have a higher percentage of some homes with levels above the current guideline, all regions had homes with high levels. Therefore, this map should not be used as a guide to deciding which areas of the province require testing and which do not. All areas of the province should be considered at risk for elevated levels of radon. The only way to know if your workplace has high levels is to test. 

Health Canada has prepared information on radon to guide home owners and workplaces in determining whether radon is a concern, including proposed corrective measures to limit exposures. Outlined below is a question/answer summary of the information prepared by Health Canada. Other questions and answers can be found on the Health Canada or Canadian Centre for Occupational Health & Safety website. 


Frequently Asked Questions

Radon is a radioactive gas that is formed naturally by the breakdown of uranium in soil, rock and water. As a gas, radon is slowly released from the ground, water, and some building materials that contain very small amounts of uranium, such as concrete, bricks, tiles and drywall. Radon gas breaks down further to form additional radioactive particles called radon daughters, or "progeny," that can be breathed into the lungs.

Radon is colourless, odourless and tasteless and cannot be detected by the senses. It can be detected with special instruments. When radon is released from the ground outside, it mixes with fresh air and gets diluted, resulting in concentrations too low to be of concern. However, when radon enters an enclosed space, it can accumulate to high concentrations and become a health risk.

Radon concentrations fluctuate seasonally, but are usually higher in winter.

Inhaled radon gas and radon progeny can breakdown further in the lungs and emit "alpha particles." Alpha particles release small bursts of energy absorbed by nearby lung tissue. This results in lung cell death or damage. When lung cells are damaged, they have the potential to result in cancer when they reproduce.

The only known health risk associated with exposure to high levels of radon in indoor air is an increased risk of lung cancer. Radon is the second leading cause of lung cancer after smoking. The risk from radon exposure is long-term and depends on the level of radon, how long a person is exposed and their smoking habits. If you are a smoker and are exposed to elevated levels of radon, your risk of developing lung cancer increases significantly.

Other than lung cancer, there is no evidence that radon exposure causes other harmful health effects such as any other form of cancer, respiratory diseases such as asthma, or symptoms such as persistent coughing or headaches.

Following a risk assessment and a public consultation, the revised guideline was approved by the Federal Provincial Territorial Radiation Protection Committee in October 2006. The new guideline of 200 Bq/m³ makes Canada's guidelines lower than or equal to most every other major industrialized country.

"Remedial measures should be undertaken in a dwelling whenever the average annual radon concentration exceeds 200 becquerels per cubic metre (200 Bq/m³) in the normal occupancy area. The higher the radon concentration, the sooner remedial measures should be undertaken. When remedial action is taken, the radon levels should be reduced to a value as low as practicable. The construction of new dwellings should employ techniques that will minimize radon entry and will facilitate post-construction radon removal, should this subsequently prove necessary."

Note: The Province of New Brunswick does not regulate radon exposures in workplaces, except for underground mines. As with the practice at provincially operated workplaces (schools, health care facilities, etc.), WorkSafeNB recommends Health Canada's guidelines be followed in workplaces where non-radiation workers conduct work.

Health Canada recommends dwellings be tested for a minimum of three months, ideally between September and April when windows and doors are typically kept closed.

Long-term radon detectors commonly used are:

  • Alpha track detection
  • Electret ion chamber 

There are two options for testing for radon: one is to purchase a do-it-yourself radon test kit and the other is to hire a radon measurement professional. If you choose to perform the test yourself, radon detectors can be purchased over the phone, from the Internet or from some home improvement retailers. The radon test kits will include instructions on how to set up the test and send it back to a lab for analysis. In some cases, the lab analysis fees and postage are additional.

Note: There is no legal requirement for employers to test for radon except in an underground mine. However, the only way for an employer to know if they are compliant with the guideline is to test.

If you choose to hire a service provider to perform the radon test, Health Canada suggests you ask the service provider the questions outlined below.

Questions to consider asking the service provider

Health Canada recommendations

  • What type of radon test device do you provide (short-term or long-term)?
  • Long-term (min. three months)
  • Are you certified or trained to provide radon measurement services?


  • Are you familiar with Health Canada's measurement protocols*?
  • Yes

To provide a realistic estimate of the radon exposure of the occupants, all measurements should be made in the normal occupancy area of the lowest lived-in level of the building. The normal occupancy area is defined as any area occupied by an individual for more than four hours per day.

If your home or building tests above the guideline, you should hire a certified radon professional to determine the best and most cost effective way to reduce the radon level in your home. The most common radon reduction method is called sub-slab depressurization. With this solution, a pipe is installed through the basement sub-flooring to an outside wall or up through to the roof line with a small fan attached that draws the radon from below the house to the outside before it can enter your home. This type of system can reduce the radon level in a home by more than 90%. Increasing ventilation and sealing major entry routes can also help reduce radon levels, but their effectiveness will be limited depending on how high the radon level is and the unique characteristics of each building.

Contact the Canadian National Radon Proficiency Program (C-NRPP) at 1 800 269-4174 or visit the C-NRPP website for a list of certified service providers who can help reduce radon levels in your home or building.


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