Radon Health Risks
1 What Makes Radon Dangerous?
As radon itself decays, it produces a sequence of radioactive decay products. These decay products are heavy metals: polonium, bismuth and lead. Radon itself is chemically inert and it does not stick to lung tissue when it is ingested. The metallic decay products (which in some cases may be electrostatically charged) adhere to dust particles and the lung surface. When they decay, wave length and particle radiation are produced resulting in lung tissue damage and potentially mutagenic cells. The greater the exposure, the greater the risk of developing lung cancer.
2What Is the Cancer Risk that is Associated with Radon?
Radon is a Class A carcinogen. This classification was designated based on scientific studies that used human data and animal data, as well as, a solid understanding of the effects of ionizing radiation on lung tissue. Radon is estimated to cause approximately 21,000 lung cancer deaths annually. In fact, the Surgeon General has warned that radon is the second leading cause of lung cancer in the United States. Only smoking causes more lung cancer.
3How does radon affect me?
Radon is the second leading cause of lung cancer in the United States and there is no level of radon that is considered to be safe. The Federal EPA, however, recommends that action be taken if indoor levels exceed 4.0 pCi/l (pico curies per liter). At a 4.0 pCi/l exposure rate there is a potential for 7 out of every 1000 people to contract lung cancer. Radium in the concrete is a serious problem because as radium breaks down it produces radioactive radon gas which becomes air born as it is emitted from the concrete. To achieve energy efficiency goals, town homes and apartments, which are almost totally surrounded by concrete, have relatively low air exchange rates. This can allow the radon that is emitted from the concrete to build up to dangerous concentrations.
4What Are the Risks Associated with the US EPA’s 4.0 pCi/l Standard for Corrective Action?
The US EPA and the NJDEP have established a standard for corrective action at 4.0 pico curies per liter (pCi/l). Other environmental exposures are regulated to reduce the lifetime risk of cancer to one in 100,000. The EPA lists radon risk exposure to 4.0 pCi/l for a lifetime (18 hours per day) to cause 7 additional lung cancers in a thousand non-smokers or 62 additional lung cancers in 1000 smokers. The risk is considered linear which means even a 2.0 pCi/l exposure over a lifetime would cause 3 additional cancers in a 1000 non-smokers. Fortunately, most of us are not exposed for a lifetime; however, we would get a similar risk if we were exposed to four times as much for a quarter of a lifetime or 16.0 pCi/L in your bedroom for 17 years. Read more about radon health risks here.
5What Are the Radon Concentration in the Area that I Am Concerned About?
The US EPA and the New Jersey DEP have produced maps indicating areas of radon concentrations. New Jersey has designated all municipalities into one of three tiers based on the potential for a home or school to have a radon problem. All new residential homes and schools constructed in Tier One must have passive radon piping and comply with the Radon Hazard Sub-Code N.J.A.C. 5:23-10. All schools constructed under the administration of the New Jersey Schools Development Authority (NJSDA) must have radon preconstruction piping installed. New Jersey Tier Map EPA Zone Map
6How Does Radon Get into Homes and Buildings?
Radon is drawn into buildings from the underlying soil by the negative pressures that are associated with the interior envelope structure. The three most common factors are temperature differentials where warm air exiting the upper portion of the building induces stack effect. Wind and exhaust appliances create additional vacuum. These forces that are similar to lift associated with an airplane wing draw in soil gases through cracks, conduit openings and other
7How Do You Reduce Radon?
The primary method for reducing radon is active soil depressurization. This is accomplished by installing a radon mitigation scheme. A radon mitigation system prevents radon entry into a building by creating a negative pressure beneath the slab. A radon mitigation system will draw radon from beneath the slab, through PVC piping to the exterior of the building where it is vented above the roofline and quickly diluted with ambient air. The radon mitigation system also removes moisture and other soil borne pollutants that can enter the building and, therefore, improve the overall indoor air quality of the building.