You may have heard about people testing radon levels when either selling or buying a home overseas. But how high are the levels of radon in Australia, what health risks does it pose to homeowners and when should you have a radon inspection conducted?
In this article, we arm homeowners, sellers and potential home buyers with enough information to make an informed decision about radon testing and whether or not it’s needed in Australia.
Key Takeaways
- Low Risk in Australia: Radon levels in Australian homes are generally very low compared to the global average, and the health risk is considered minimal for the general population.
- A Carcinogen: Despite low levels, radon is a known carcinogen and the second leading cause of lung cancer in other countries, posing a higher risk to smokers exposed to it.
- Invisible Threat: As radon is a colourless, tasteless, and odourless gas, it can only be detected with proper testing.
- Testing is Simple: If you have concerns, testing your home’s radon levels is simple and affordable through ARPANSA.
- Regional Variations Exist: While the national average is low, some regions may have slightly higher concentrations due to local geology
What is radon in homes?
Radon is a colourless, tasteless, and odourless radioactive gas that occurs naturally in the ground. It’s a by-product of uranium decay, which is usually found in rocks and soil.
The main reason people should avoid coming into contact with this radioactive gas is its potential to cause cancer. As radon can move through cement, sheetrock, and other building materials, it can easily penetrate the foundation of your home. In areas with high concentrations of radon, this is something to be aware of, as it poses several health risks to humans.
What are the health impacts and risks?
Sadly, in many countries, including the U.S., radon gas is the second leading cause of lung cancer, exceeded only by cigarette smoking. The risk of developing lung cancer from radon exposure depends on the level of radon consumed over time; the higher the levels of radon in the air we breathe, the bigger the risk. Some reports have indicated radon exposure to be more harmful than if asbestos is found in your home.
The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) confirms that radon is a known carcinogen. However, the good news is that Australian homes generally have very low radon levels compared to the global average. A nationwide survey conducted in the 1990s showed the average concentration was around 10 Bq/m³, which is about one-quarter of the world’s indoor average.
For the non-smoking Australian population, the risk for lung cancer associated with radon exposure is considered very small. However, there is a significantly higher risk for smokers and ex-smokers who are also exposed to radon. It’s also important to note that children are more sensitive to radiation than adults due to their faster breathing rates. The risk from radon exposure is cumulative over a lifetime.
Also read: Why You Should Have A Moisture & Mould Inspection
Where can you find radon in Australia?
The average radon levels in Australia are well below the worldwide average. However, radon can always be found in the air we breathe. The concentration of radon gas is higher indoors than outdoors, as buildings have the effect of trapping it. Radon levels are also dependent on the type of house and its ventilation.
Typically, subfloor areas, particularly those situated below ground level, tend to confine excess levels of radon, which would otherwise disperse safely into the environment. The gas can easily accumulate in low-lying areas such as basements and from there disperse to the ground floor areas of the home.
While national averages are low, some regional areas have been identified as having slightly higher radon potential. These include areas in New South Wales such as Goulburn, Yass, Queanbeyan, and Campbelltown, as well as parts of Queensland and South Australia. The presence of uranium in underlying rocks and soil is the primary factor, but radon can also enter from uranium-bearing building materials.
A Deeper Look at Radon Measurement
The most common unit for measuring radon concentration is Becquerels per cubic metre (Bq/m³). One Becquerel represents a single radioactive decay per second. Therefore, a reading of 100 Bq/m³ means that there are 100 radioactive decays per second in every cubic meter of air.
It’s important to understand that radon levels can fluctuate significantly throughout the day and with seasonal changes. For this reason, there are two primary types of testing, both of which serve different purposes:
- Short-Term Testing (Less than 90 days): These tests are conducted over a period of 2 to 7 days. They provide a quick snapshot of the radon concentration in a home but are highly susceptible to daily fluctuations caused by changes in ventilation, temperature, or weather.
- Long-Term Testing (More than 90 days): This is the most reliable way to measure radon levels. By leaving the monitor in place for at least 90 days, it captures the seasonal variations and provides a much more accurate average of the home’s radon concentration over an extended period. This method is the best way to determine if a home has a long-term radon problem that requires mitigation.
Radon Test Kit
If you’re worried about radon levels at home, testing is simple. ARPANSA offers affordable radon monitors for testing.
According to ARPANSA, recommended levels are 200 Bq/m³ for households and 1000 Bq/m³ for workplaces. They offer radon meters for rent to measure indoor concentrations accurately, requiring seven days’ untouched placement in each room. These meters display radon concentrations in Becquerels per cubic meter (Bq·m⁻³).
Renting a meter costs $75.00 for return express post delivery, with a hire duration of 30 days.
Which homes need a radon inspection/test done?
In countries with higher measurements of radon levels, continuous radon testing conducted by a professional inspector is recommended. Because the radon levels in homes are generally very low in Australia, a professional test is usually not needed. If you wish to measure the indoor radon concentration from within your home, you can hire a personal-use radon monitor and radon test kit from ARPANSA.
What if your home has high radon levels?
While high radon levels are not a significant concern in Australia, if you do a radon test and the levels are high, there are mitigation measures you can take.
The most effective method for homes with a concrete slab is sub-slab depressurization. This involves using a fan and a pipe system to draw radon gas from beneath the foundation and vent it safely outside and away from the home. For homes with suspended floors or crawlspaces, active sub-floor ventilation can be used. This involves a fan to increase air exchange and prevent the gas from accumulating.
If you have any questions or particular concerns, get in touch with us!
Contact Inspect My Home
Inspect My Home is one of Australia’s largest and most trusted building and pest inspection companies. Our team of professional property inspectors are trained to carry out thorough pre-purchase property inspections, pest inspections and a variety of other services.
A comprehensive property inspection by an experienced professional will uncover any issues. It will help you make an informed decision based on the facts.
All services are followed by a detailed report by our building professionals, emailed 24 hours after the inspection. Call today on 1300 337 447 or conveniently book online.
Frequently Asked Questions about Radon in Australia
Do newer, more energy-efficient homes have a higher risk of radon?
Newer, energy-efficient homes are often built to be airtight to reduce heating and cooling costs. This can, in some cases, trap indoor air and reduce ventilation, potentially leading to higher concentrations of radon if it is entering the home from the ground.
Are there other sources of radon besides the soil?
While soil is the primary source, radon can also be present in bore water (well water). Using bore water for showers or in a hot tub can release radon into the air, which can then be inhaled. However, this is generally a minor source of exposure.
What’s the difference between radon and thoron?
Both are naturally occurring radioactive gases. Radon (specifically Radon-222) is a decay product of uranium, while Thoron (Radon-220) is a decay product of thorium. While thoron is also present, it has a very short half-life (about 55 seconds), meaning it doesn’t travel far from its source. Radon has a much longer half-life (3.8 days), allowing it to move through the ground and accumulate indoors, making it a more significant health concern.
Should I be worried about radon if I don’t have a basement?
No, radon can enter any home, not just those with basements. It can seep through cracks in concrete slabs, foundations, and walls at ground level. However, basements and subfloor areas are more susceptible because they are typically in direct contact with the soil.
What is the “Radon Map of Australia” and can I use it?
The most accurate public information is found in the ARPANSA national survey data. This data provides average radon concentrations based on postcode districts or SA2 regions, offering a great way to understand the general radon potential of your area.
