Quartz countertops have become an increasingly popular option for kitchen and bathroom renovations in recent years. Made from ground natural quartz crystals combined with resins and pigments, quartz counters are valued for their durability, low maintenance, and wide variety of colors and patterns. However, some homeowners have expressed concerns about potential radon gas emissions from quartz countertops. So do quartz countertops emit radon?
What is Radon?
Radon is a naturally occurring radioactive gas that forms from the decay of uranium in soil and rock. It is colorless, odorless, and tasteless. Radon gas seeps into homes through cracks in floors and walls and can accumulate to dangerous levels in enclosed spaces like basements.
Prolonged exposure to elevated radon levels is the second leading cause of lung cancer after smoking. The EPA and WHO estimate that radon causes over 20,000 lung cancer deaths per year in the United States.
The main source of radon is the soil and rock surrounding a home. Granite, marble, and other natural stone used for countertops contain trace levels of uranium that can produce radon gas through natural radioactive decay. This has raised concerns that quartz counters made from ground quartz rock may also emit radon.
Do Quartz Countertops Contain Uranium?
Natural quartz crystals do contain tiny amounts of uranium, thorium, and radium. These radioactive elements decay over time and produce radon gas.
However, the amount of uranium in quartz is generally very low, around 10-30 parts per million (ppm). Granite, in comparison, can contain 15-55 ppm uranium. The EPA estimates average background radiation from soil and rocks to be around 50 ppm uranium.
So while quartz does have trace levels of radioactive substances, the amounts are considered low and comparable to normal environmental background radiation.
Can Radon Diffuse Through Quartz Countertops?
For radon to pose a risk, it must first be released from the natural stone and diffuse into the airspace.
Studies show natural stone emits only a small fraction of its contained radon. The mineral structure of quartz makes it highly impermeable, limiting radon diffusion.
Researchers have measured radon flux, or the rate of radon release, from various stones:
- Quartzite: 0.001-0.033 pCi/cm2/h
- Granite: 0.01-0.1 pCi/cm2/h
- Marble: 0.003-0.03 pCi/cm2/h
This compares to over 20 pCi/cm2/h radon flux measured from soil, showing stone surfaces emit relatively little radon.
Quartz is considered to have a low radon flux due to its dense non-porous nature. The polymer resins used in making engineered quartz further reduce radon diffusion.
Do Quartz Countertops Elevate Indoor Radon Levels?
Since quartz emits such small amounts of radon, it is very unlikely to significantly increase radon levels in a home.
Researchers have done radon tests in homes with quartz and other natural stone countertops and found normal background concentrations:
- A 2008 study tested radon in 39 homes with granite countertops in New York State. Only one home had elevated radon above 4 pCi/L, attributing it to high radon levels from the soil rather than countertops.
- A 2013 study in Quebec tested radon in over 200 homes with quartz or granite counters. Radon levels were below 2 pCi/L in 99% of homes, similar to homes without stone counters.
EPA testing has also confirmed radon levels in homes remain unaffected by granite and other natural stone countertops.
How Much Radon is Dangerous?
Radon only poses health risks at sustained elevated levels. The EPA recommends taking action to reduce indoor radon at or above 4 pCi/L.
Under most building codes, granite and quartz countertops are exempt from radiation standards because they emit such low radon levels.
For comparison:
- Average indoor radon level: 1.3 pCi/L
- EPA recommended action level: 4 pCi/L
- Average outdoor radon: 0.4 pCi/L
- Smoker’s home radon level: 20+ pCi/L
Overall, quartz countertops are expected to increase indoor radon by less than 0.5 pCi/L, well below dangerous levels.
Tips for Reducing Indoor Radon Levels
If you have elevated radon levels from the ground below your home, here are some ways to reduce concentrations:
- Install a radon mitigation system with pipes and fans venting radon from below the basement slab to the outdoors. This can reduce levels by over 90%.
- Seal cracks in floors and walls that allow soil gas to enter. Use caulks, sealants, and gaskets.
- Increase under-floor and soil ventilation.
- Install a radon detection system with automated fan activation at high concentrations.
Avoid smoking, which can greatly increase lung radon exposure and damage.
Should You Avoid Quartz Countertops Due to Radon?
Based on all available research, radon emission from quartz countertops is negligible and not a health concern in homes. Even granite countertops emit such low radon that they are exempt from regulations.
The main factors that can cause high indoor radon are:
- Local geology – Some rock and soil contain more uranium, producing higher ground-level radon that can enter homes.
- Home construction – Tightly sealed homes with less under-floor ventilation trap radon gas from the ground.
- Lifestyle factors – Smoking and more time spent indoors increases lung radon exposure.
Quartz counters do not meaningfully contribute to indoor radon. If you have elevated levels, mitigation and ventilation are the solutions – not avoiding quartz.
With their durability, low maintenance, and stylish appearance, quartz countertops remain a smart choice for kitchens and bathrooms. Radon is not a health concern.
Frequently Asked Questions About Quartz Countertops and Radon
Can quartz countertops increase radon levels in my home?
It is highly unlikely. Many studies have confirmed quartz and granite countertops emit extremely low levels of radon, insufficient to raise indoor concentrations above background levels. Soil gas entering through cracks in the foundation is the primary radon source.
How much radon do quartz countertops emit?
Researchers have measured radon flux from quartz surfaces to be 0.001-0.033 pCi/cm2/h, hundreds of times lower than soil. This tiny amount cannot significantly increase indoor radon.
Is radon only an issue with granite countertops?
No, all natural stone contains trace uranium that produces radon through radioactive decay. But research shows granite, marble, and quartz all emit radon at rates well below danger levels. Granite can have slightly more uranium than quartz but still emits low radon.
Can sealing quartz reduce radon emissions?
Sealing is not necessary as quartz already has a very low radon flux due to its non-porous structure. Resins used in manufacturing quartz also limit radon diffusion. Sealing may have other benefits like improving stain resistance but does not affect radon.
How can I test radon levels in my home?
You can purchase inexpensive charcoal radon detectors from home improvement stores that allow long-term radon monitoring. Independent radon testing labs also offer detection services. Call your state radon office for local testing options. The EPA recommends annual radon testing.
Should I install a radon mitigation system with quartz counters?
Only install radon mitigation if a test confirms elevated levels above 4 pCi/L. Quartz counters do not emit enough radon on their own to require mitigation. Mitigation reduces radon from the ground before it can enter your home.
Can a radon detector distinguish between soil vs. countertop radon?
Basic radon tests only measure total indoor radon levels. But studies clearly show quartz and granite counters alone will not raise home levels. Special testing after sealing foundation cracks can help isolate the radon source.
Do countertop sealants prevent radon emissions?
Sealants help resist stains but do not meaningfully reduce radon emissions from quartz and granite counters. Their dense non-porous structure already limits radon diffusion. Proper soil sealing and ventilation are more effective.
Conclusion
In summary, existing research indicates radon emission from quartz countertops is negligible and highly unlikely to impact indoor air quality. Quartz has a very low natural radon flux, and manufacturing processes further reduce radon diffusion. Given the durability and aesthetic advantages of quartz counters, radon emission should not be a major concern for homeowners. As with any home, annual radon testing is wise to monitor levels, especially in high-risk areas. But quartz counters themselves are considered very low radon emitters. Focus mitigation efforts like foundation sealing on the primary radon source – the soil – if elevated levels are detected. With minimal maintenance requirements and styling flexibility, quartz counters remain one of the most popular options for today’s kitchens and baths.