Arizona — 5M metro

Radon in Phoenix,
AZ

The Phoenix metro sits in EPA Zone 2, with Arizona Department of Health Services reporting 11–15% of tested homes exceeding the action level. Northern Valley communities near Anthem and Cave Creek show higher rates than the central urban core.

Risk Level

Moderate Risk

1–3.5 pCi/L

Typical range (area avg.)

EPA action level: 4 pCi/L

Why Phoenix Has Moderate Risk Radon

Phoenix's alluvial desert soils contain moderate uranium from granite and volcanic parent materials in the surrounding mountain ranges. The dry desert conditions allow radon to migrate freely through soil, but rapid air exchange in warm months naturally dilutes indoor concentrations.

Local Housing and Radon Risk

Phoenix's slab-on-grade construction (no basement) significantly reduces radon risk compared to full-basement regions. However, homes with bonus rooms, multi-story structures with lower interior floors, and older properties are still worth testing.

Testing Advice for Phoenix Residents

Phoenix's extreme heat means most homes are tightly sealed with air conditioning for 6+ months of the year — this can concentrate radon despite the desert climate. Test during summer months for a worst-case reading.

How to Test Your Phoenix Home

Step 1: Choose Your Test Type

For initial screening, a charcoal short-term test kit ($12–$25) placed for 48–96 hours provides a quick result. For the most accurate reading, a long-term alpha-track test ($20–$35) left in place for 90+ days accounts for seasonal variation — especially important in Phoenix's climate.

Step 2: Place the Test Correctly

Test in your lowest livable level — basement if you have one, otherwise the first floor. Keep the test 20 inches from the floor, away from windows and exterior walls. Close windows and doors 12 hours before and during the test for accurate results.

Step 3: Interpret Your Results

Below 2 pCi/L: low concern, retest every 2 years. 2–4 pCi/L: consider mitigation, retest in 2 years. 4 pCi/L or higher: the EPA recommends mitigation. Above 8 pCi/L: prioritize mitigation promptly.

Step 4: Hire a Certified Mitigator if Needed

If your test result is at or above 4 pCi/L, hire a certified radon mitigator. In Arizona, always verify your contractor's state certification. Sub-slab depressurization — the most effective mitigation method — typically costs $900–$1,700 installed in the Phoenix area.

Frequently Asked Questions — Radon in Phoenix

Is radon a real problem in Phoenix?

Yes. The Phoenix metro sits in EPA Zone 2, with Arizona Department of Health Services reporting 11–15% of tested homes exceeding the action level. Northern Valley communities near Anthem and Cave Creek show higher rates than the central urban core. The EPA recommends all homes be tested regardless of location — radon levels can vary significantly even between neighboring properties.

How much does radon mitigation cost in this area?

In the Phoenix area, professional radon mitigation (sub-slab depressurization) typically costs $900–$1,700 installed. This is a one-time cost that reduces radon by 50–99%. The system requires minimal maintenance and a mitigator can typically complete the work in 3–5 hours.

Should I test if I have a new home?

Absolutely. New homes built with radon-resistant features still show elevated levels in testing — construction conditions and local geology vary too much to assume any home is safe. Test within the first year of occupancy, especially if your home has a basement.

Can I test radon myself, or do I need a professional?

DIY testing is reliable and recommended as a first step. Short-term kits ($12–$25) and long-term kits ($20–$35) are accurate when placed and returned correctly. Professional testing is only required for real estate transactions in some states. If your DIY test shows elevated levels, use a certified professional for both confirmation testing and mitigation.