Radon: the invisible gas behind 1 in 7 lung cancer deaths.
Odorless, colorless, and radioactive, radon seeps up from the soil and concentrates indoors, where it becomes the leading cause of lung cancer in people who have never smoked. The only way to know your level is to measure it.
What is radon?
Radon is a naturally occurring radioactive gas produced by the decay of uranium in soil, rock, and groundwater. Because it is a gas, it moves freely through the ground and rises into buildings through cracks in foundations, construction joints, sump pits, crawl spaces, and gaps around service pipes. Once inside, it can accumulate to concentrations far higher than the open air outdoors.
You cannot see, smell, or taste it, and it produces no immediate symptoms. Radon is measured in picocuries per liter (pCi/L). The U.S. Environmental Protection Agency sets an action level of 4.0 pCi/L, and the World Health Organization recommends a more conservative reference of about 2.7 pCi/L. There is no level considered completely risk-free, the goal is to measure your home and reduce exposure as far as is practical.
As radon decays it releases tiny radioactive particles. When inhaled, these particles lodge in lung tissue and deliver localized doses of radiation over years of exposure, which is why radon is a chronic, cumulative risk rather than an acute one.
Health effects of radon exposure
The EPA, the U.S. Surgeon General, and the World Health Organization all identify radon as a serious public health risk. Its danger comes not from a single high exposure but from years of breathing slightly elevated levels at home or work.
Lung cancer
Radon is the second leading cause of lung cancer overall and the number-one cause among people who have never smoked. The EPA estimates it contributes to roughly 21,000 lung cancer deaths in the United States each year, more than drunk-driving fatalities.
Smoking multiplies the risk
Radon and tobacco smoke are powerfully synergistic. For someone who smokes, elevated radon dramatically increases lung cancer risk beyond what either exposure causes alone, making testing especially important in households with current or former smokers.
A long latency period
Because the radiation dose accumulates slowly, there are no early warning signs. Lung cancer linked to radon typically develops years to decades after sustained exposure, which is precisely why testing, not symptoms, is the only reliable way to identify the risk.
Children and long-term occupants
People who spend the most time at home, children, those who work from home, and retirees, accumulate the greatest cumulative exposure. Bedrooms and lower-level living spaces, where people spend long uninterrupted hours, are the rooms where elevated radon matters most.
A measurable, fixable risk.
The science on radon is settled, and the numbers are the reason every air quality assessment should include it.
cause of lung cancer in people who have never smoked, and the second leading cause overall, per the EPA and U.S. Surgeon General.
estimated radon-related lung cancer deaths in the U.S. each year, more than are caused by drunk driving.
Oregon homes is estimated to have radon at or above the EPA action level of 4.0 pCi/L, per the Oregon Health Authority, far above the national average.
pCi/L is the EPA action level. The WHO recommends a more protective reference of about 2.7, there is no risk-free level.
How radon enters your home
Radon is drawn indoors by the natural pressure difference between the soil beneath a building and the heated air inside it. The most common entry points include:
- Foundation cracks and joints. Hairline cracks in slabs and foundation walls, and the joint where wall meets floor, are the most common pathways.
- Crawl spaces. Exposed soil in a crawl space lets radon enter freely and migrate into living areas, a frequent configuration in older Pacific Northwest homes.
- Sump pits and drains. Open sump systems and untrapped floor drains connect directly to the soil gas around the foundation.
- Construction and utility penetrations. Gaps around plumbing, electrical, and gas-line penetrations give radon a direct route inside.
- Well water. In homes on private wells, radon dissolved in groundwater can be released into the air during showering, dishwashing, and laundry.
- Basements and lower levels. The lowest occupied level sits closest to the source and typically shows the highest concentrations.
How Illumenair tests for radon
Radon levels are invisible and vary enormously from one home to the next, even between neighboring houses on the same street. Two homes built on the same soil can read completely differently depending on foundation type, ventilation, and how the building is operated. The only way to know your level is to measure it directly.
Radon is distinct from the bioaerosols and particulates in our standard panel, it is a radioactive gas, not a particle, so we measure it with a dedicated continuous radon monitor rather than our real-time particle analyzer. When you add radon to an Illumenair assessment, you receive:
- Continuous monitoring placed in the lowest occupied level for an averaged reading, rather than a single instantaneous snapshot.
- Lowest-level focus on the rooms where occupants actually spend time and where radon tends to concentrate.
- Clear interpretation against EPA and WHO reference levels, with plain-language guidance on whether mitigation is warranted.
- Multi-parameter context, radon measured alongside mold, humidity, VOCs, and the rest of your panel, for a complete picture in one visit.
The good news: radon is among the most fixable indoor air problems. If your level is elevated, a properly designed sub-slab depressurization system routinely brings it well below the action threshold, a one-time fix that protects the home for years.
Radon testing in Portland, Vancouver & Ridgefield
Radon is a local concern, not a national average. Geology drives everything, and our service area sits squarely in radon country, much of the Portland metro and SW Washington rests on soils and bedrock capable of producing elevated indoor radon. Multnomah, Clackamas, Washington, and Clark counties all carry documented elevated levels, and individual homes within any zone can test high regardless of the regional map.
The region's housing stock compounds the issue: many homes have basements, daylight basements, or vented crawl spaces that sit in direct contact with soil gas, and tightly weatherized homes can trap radon at higher concentrations through the long heating season. Because radon varies house by house, a neighbor's result tells you nothing definitive about your own home.
Illumenair serves Portland, Vancouver, and Ridgefield, adding continuous radon monitoring to a complete, room-by-room air quality assessment. View our pricing for assessment options, or visit our providers page if you're a clinician recommending environmental testing for a patient.
Don't guess about radon. Measure it.
Add radon monitoring to a whole-property air quality assessment and measure it alongside mold, humidity, VOCs, and more, room by room, in a single visit. We serve Portland, Vancouver, and Ridgefield.
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