RADON A LESSER KNOWN GAS THAT AFFECTS THE ENVIRONMENT

Radon gas in Cornwall is a significant environmental and public health concern, primarily driven by the region’s unique granite geology, which contains higher-than-average levels of uranium. As this uranium decays, it produces radon, a colorless, odorless, radioactive gas that escapes through soil and rock fractures. 

Environmental Impacts

• Atmospheric Dispersion: Outdoors, radon gas is quickly diluted to very low, negligible concentrations.
• Soil and Groundwater Contamination: Radon can dissolve in groundwater and be present in, or emanate from, soil, particularly in areas with permeable ground and granite bedrock.
• Legacy Mining Contamination: Historical uranium mining in Cornwall has left behind radiological contamination across many abandoned mine sites, with some underground areas recording extremely high, dangerous concentrations.
• Accumulation in Buildings: Because of the high radon potential in the ground, buildings in Cornwall are at a higher risk of trapping radon gas, which enters through cracks in floors,

Environmental and Health Risks in Cornwall

• High Radon Levels: Much of Cornwall is designated a “radon affected area” with many parts having >1% (and in some areas >30%) of homes above the 200 Bq m$$ action level.
• Lung Cancer Risk: Radon is the second leading cause of lung cancer in the UK. It decays into radioactive particles that, when inhaled, can damage lung tissue.
• Higher Background Radiation: The average annual radiation dose for the Cornish population is 7.8 mSv, significantly higher than the UK average of 2.7 mSv.

Mitigation and Management

• Building Regulations: New buildings in Cornwall often require protective measures, such as radon-proof barriers or membranes beneath floors.
• Remediation: Existing homes with high levels can be remediated using positive pressure ventilation systems or radon sumps, which are designed to vent the gas away from the building.
• Testing: The UK Health Security Agency (UKHSA) recommends testing homes in high-risk areas. 

While radon is a natural, unavoidable part of the environment in Cornwall, the risks are managed through awareness, building design, and mitigation efforts.