Markham, IL Radon Levels

Q: What EPA Radon Zone is Markham in?

Markham is in Cook County, EPA Zone 2.

Q: How much does radon mitigation cost in Markham?

Radon mitigation typically costs between $800 and $2,000. Most standard systems fall in the $1,000-$1,500 range.

Check local Markham radon levels and find certified testing and mitigation professionals to keep your home safe

Markham, IL Radon Facts

EPA Radon Zone Zone 2 — Moderate Risk 2–4 pCi/L (Zone 2)

County Cook County, IL

Zip Code 60428

Located in Cook County along the southern suburban reaches of the Chicago metro, Markham sits on glacial till deposits from the Wisconsin glaciation that create soil conditions highly favorable for radon gas production. The community's housing stock consists predominantly of single-family homes built between the 1950s and 1990s, most with full poured-concrete or block basements where radon can accumulate. While radon testing data for zip code 60428 is currently limited, homeowners are strongly encouraged to test their properties given the area's geological characteristics.

6.44

pCi/L area average

Above EPA Action Level

Cook County average: 6.44 pCi/L, based on 82 user-submitted tests across 40 cities in the county. No homeowner readings have been submitted for Markham itself yet, so this county figure is the closest available benchmark. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

Markham, IL Radon Mitigation

Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.

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Radon Readings Near Markham, IL

No homeowner tests have been submitted for Markham yet. The closest cities with user-submitted radon data are shown below — explore them to gauge local conditions. Radon varies by home, so testing is the only way to know your level.

City	Distance	Avg User Level	Readings
Blue Island	4.1 mi	4.00 pCi/L	1
Flossmoor	4.1 mi	5.00 pCi/L	1
Matteson	6.7 mi	15.00 pCi/L	1
Palos Heights	6.8 mi	5.00 pCi/L	1
Tinley Park	6.9 mi	7.67 pCi/L	3
Richton Park	8.3 mi	3.00 pCi/L	2
Orland Park	9.1 mi	7.00 pCi/L	3
Burbank	10.8 mi	2.00 pCi/L	1

Cook County Radon Profile

Cook County is mapped as EPA Radon Zone 2, where the local geology is predicted to produce moderate indoor screening levels between 2 and 4 pCi/L. Homeowner-submitted tests from 40 cities in Cook County average 6.44 pCi/L across 82 tests — above the EPA's 4 pCi/L action level, reinforcing the need for testing across the county. Radon is the second leading cause of lung cancer in the United States, and a short-term test is the only way to confirm a specific home's level in Cook County.

Radon FAQ for Markham, IL

What EPA Radon Zone is Markham in?

Markham and the 60428 zip code are in Cook County, which has an EPA assigned Radon Zone of 2. A zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L.

Why are radon readings shown from areas near Markham?

No homeowner radon tests have been submitted for Markham yet. Because radon is driven by regional soil and bedrock geology, readings from the closest cities—and the Cook County average—are the best available indicator of local conditions until Markham homeowners submit their own results. The EPA still recommends testing every individual home, since levels can vary significantly from house to house.

How much does radon mitigation cost in Markham?

Radon mitigation in Markham typically costs between $800 and $2,000. Most homes with standard basements can be mitigated with a sub-slab depressurization system in the $1,000–$1,500 range. Factors that can increase cost include complex foundations, crawl spaces, or very high radon levels.

Should I test for radon if I'm buying a home in Markham?

Yes. Radon testing should be part of every home purchase. A short-term radon test is typically included as part of the home inspection process and costs $150–$250. If elevated levels are found, you can negotiate mitigation as part of the sale.