Mitigate radon gas.
Healthy HouseTM CleanAir Tip
Radon gas is a colorless, odorless, tasteless, invisible gas that results from the natural breakdown (radioactive decay) of uranium that is naturally found in the earth.
Radon gas concentration levels will vary depending on your location and soil/bedrock makeup. Some geographic areas have lower levels on-average and some are considered to have elevated levels. But even within any given geographic region, radon levels can vary dramatically.
In the United States, Radon is typically measured in picocuries per litre (pCi/L) and in Canada it is measured in becquerels per cubic meter (Bq/m3). The EPAs take action limit is 4 pCi/L. The Institute for Building Biology and Ecology recommends taking action at 2 pCi/L. Ideally you want your levels to be as close to zero as possible.
For nonsmokers, radon exposure is the leading cause of lung cancer death. A radon level of 4.0 pCi/L is equal to 200 chest x-rays per year or 8 cigarettes per day.
Radon concentrations are typically the highest in the parts of the home that are closest to the points of infiltration like the lower levels, but that is not always the case. Radon can easily enter the living space through cracks, floor drains, and sump pump basins.
Radon is commonly mitigated by installing a sub-slab soil suction system. This system is basically a fan that vents to the outdoor air. It pulls air from below the slab or basement floor and is configured to pull from the cavity of dirt beneath the slab. You can also attach this type of radon mitigation system to a sump pump basin or drainage tile system.
For maximum effectiveness, it is important to ensure the air is being pulled from the earth below the slab and not being pulled from in the house. Sealing any cracks in the basement and sealing sump pump basins will also help lower radon levels.
Additional mitigation steps need to be taken for homes with crawl spaces. Buildings with crawl spaces need extra consideration including whether it is a temperature conditioned space as well as consideration to the types of construction materials including the walls and floor of the crawl space.
Radon levels in homes can vary significantly over time. It is not uncommon to see radon levels change by a factor of 2 to 3 over even a day period, and variations occurring from season to season can be even larger.
Healthy House can guide you through radon measurement and mitigation whether you are nearby or afar by providing testing equipment and consultation services.