Correspondent
Radon Awareness: What Every Homeowner Needs to Know.
The gas in question is radon, a radioactive, colorless, and odorless gas that naturally exists in various parts of the UK and other countries worldwide. It originates from radioactive elements like uranium found in rocks and soils, emitting varying quantities or concentrations.
Back in the 1950s and 1960s, the United States Public Health Service conducted epidemiological studies on miners' health, which established a clear link between higher radon concentrations and incidences of lung cancer. Although radon dissipates quickly into harmless concentrations when released into the atmosphere, it can become dangerously concentrated in confined, poorly ventilated spaces such as basements, underground mines, and buildings.
In the 1970s and 1980s, more detailed research conducted in the UK shed light on radon concentrations in residential properties and other buildings, revealing that they could reach levels that posed a substantial risk of lung cancer. Following this discovery, the UK government implemented a series of policies and regulations to monitor, record, and report radon levels. They also provided guidance on mitigating radon levels in buildings. In 1991, the building regulations in the UK were updated to include mandatory radon protection measures in new constructions within radon-affected areas. Over time, these guidelines have undergone revisions.
It's important to note that radon gas itself doesn't cause tissue damage. The true culprits are the decay products or "daughters" of radon. While radon gas may be inhaled and exhaled harmlessly, the decay products, including radon-222 derived from uranium-238 and radon-220 (also known as thoron) derived from thorium-232, as well as other progeny like polonium-218, polonium-214, and polonium-210, can have damaging effects.
These isotopes have varying half-lives, ranging from half a second to 138 days. It's the precipitation of these isotopes within lung tissue and their subsequent degradation that can lead to carcinogenic effects. Radon concentration levels are measured in Becquerels per cubic meter (Bq/m³), and the action level in the UK is set at 200 Bq/m³. This represents the recommended limit for radon activity concentration in homes.
At the action level, the lifetime risk of a non-smoker developing lung cancer is less than 1 in 200. However, for current smokers, the risk significantly increases to 1 in 7. When indoor radon levels escalate to 800 Bq/m³, the lifetime risk rises even further to 1 in 100 for non-smokers and 1 in 3 for smokers.
Concentration levels of radon within buildings can vary significantly due to various factors. Location plays a crucial role, as certain areas in the UK have naturally higher radon concentrations due to the composition of the underlying bedrock. For example, buildings in Devon and Cornwall have recorded some of the highest levels to date. Additionally, buildings with greater natural or mechanical ventilation, such as those with ventilated voids beneath the ground floors, tend to have lower radon concentrations. Furthermore, buildings constructed after 1991 that incorporate radon attenuation measures are likely to have significantly lower radon levels.
To provide information on radon, organizations like Public Health England (PHE) in the UK and the United States Environmental Protection Agency (EPA) offer guidance and advice. These resources help individuals determine if their homes might be affected by radon and provide a range of remedial measures, including ventilation systems and active radon sumps that effectively extract the gas from homes.
One of the most concerning aspects of the radon issue is the lack of awareness among the general population regarding the risks associated with this invisible gas. Knowledge is the key to protection, and it's crucial that we educate ourselves and others about radon to ensure our safety and well-being.