Mold, Radon, and Lead: The Health Hazards to Check Before You Buy a Home

Quick answer: Before you buy a home, get it tested for three health hazards that a standard walk-through won’t reveal: radon (an invisible, odorless radioactive gas and the leading cause of lung cancer in non-smokers), mold (which thrives on hidden moisture and can trigger asthma and allergies), and lead (a concern in homes built before 1978, especially in paint and older water lines). A home can look flawless and still carry any of these — testing is the only way to know.

 

Your home should protect your health, not put it at risk. Here’s what to check before you sign, why it matters in the DMV specifically, and how to handle problems if you find them.

Why should health hazards be part of my home inspection?

A cosmetic tour tells you whether you like the kitchen. It doesn’t tell you what’s in the air, behind the walls, or under the paint. Radon, mold, and lead are three of the most common home health risks, and none of them are reliably visible. Catching them before closing gives you two things: peace of mind, and negotiating leverage to get problems fixed or paid for before the home is yours.

What is radon and should I test for it in Maryland?

Radon is a naturally occurring radioactive gas that seeps up from the soil and can accumulate inside homes. You can’t see it or smell it, and prolonged exposure is the second-leading cause of lung cancer overall — and the leading cause among people who don’t smoke.

 

This matters a lot locally. Prince George’s County sits in EPA Radon Zone 2, a moderate-risk zone where predicted indoor levels average between 2 and 4 pCi/L, and the county’s measured average is around 2.6 pCi/L. But averages hide the real story: because of geological variation, plenty of individual homes test well above the EPA’s action level of 4.0 pCi/L.

 

• The rule of thumb: The EPA recommends fixing any home that tests at 4.0 pCi/L or higher, and considering a fix between 2 and 4 pCi/L.
• The good news: A radon test is inexpensive, and mitigation — usually a vent pipe and fan system — is a well-understood, affordable fix that permanently lowers levels. It’s often something a buyer can negotiate the seller to install or credit.

 

Test every home, regardless of age or whether it has a basement. Zone maps show regional risk; only a test shows your home’s level.

How do I check a home for mold before buying?

Mold grows wherever there’s moisture, and the EPA is emphatic on one point: control the moisture and you control the mold. During your evaluation, look and sniff for:

 

• Signs of past or present water intrusion — stains on ceilings and walls, warped flooring, or a patched area that hints at a repaired leak
• Basement and crawl-space dampness — water can seep through foundation floors and walls
• Condensation on windows or cold surfaces, which feeds mold growth
• A persistent musty smell, which often signals mold you can’t see
• Visible spotting — mold comes in many colors, not just black

 

Mold exposure can irritate the eyes, skin, nose, throat, and lungs, and can trigger asthma attacks in people who are allergic. If you spot warning signs, bring in a professional mold assessment before closing.

 

The most important question isn’t “is there mold?” — it’s “why is there moisture?” The EPA is clear that if you don’t fix the underlying water source, mold comes back. Water-damaged areas should be dried within 24–48 hours to prevent growth in the first place.

When do I need to worry about lead?

Lead is primarily a concern in homes built before 1978, when lead-based paint was banned for residential use. Deteriorating lead paint — chipping, peeling, or disturbed during renovations — is the main exposure route, and it’s especially dangerous for young children and pregnant women. Older homes may also have lead in plumbing solder or service lines.

 

Federal law requires sellers of pre-1978 homes to disclose known lead-based paint and give you a pamphlet and a 10-day window to test. If you’re buying an older DMV home — and much of our region’s charming older housing stock qualifies — take that testing window seriously. Remediation ranges from repainting and encapsulation to more involved abatement.

What other health checks are worth doing?

• Water quality, especially on a private well — test for bacteria, nitrates, and lead.
• Asbestos in homes built before the 1980s (old insulation, floor tiles, popcorn ceilings). It’s only dangerous when disturbed, but worth knowing about before you renovate.
• Ventilation and humidity — poor airflow keeps moisture in and mold happy.

What should I do if a test comes back positive?

Don’t panic, and don’t necessarily walk away. Most of these issues are fixable, and a positive test is negotiating power:

 

• Request repairs — ask the seller to remediate before closing.
• Request a credit — take a closing-cost credit and handle the fix yourself with a trusted contractor.
• Adjust your offer — factor the remediation cost into your price.

 

The worst outcome is not finding out. The best outcome is finding out before the home is legally yours, while the seller still has an incentive to help.

Frequently asked questions

Are radon and mold tests part of a standard home inspection? Usually not. A standard inspection covers structure and systems. Radon and mold testing are typically separate add-ons — well worth the modest extra cost.

 

How much does radon mitigation cost? It varies, but a residential radon mitigation system is a relatively affordable, one-time fix that permanently reduces levels. Get a quote and use it in negotiations if the home tests high.

 

Is a little mold a dealbreaker? Not by itself. Small amounts from a fixed moisture problem may be minor. The concern is active moisture and larger or hidden growth. A professional assessment tells you which you’re dealing with.

 

Do newer homes need these checks too? Yes for radon and mold — both occur regardless of a home’s age. Lead is mainly a pre-1978 concern, so newer construction is generally in the clear on that one.

 

Reggie Butler is Broker/Owner of CENTURY 21 Envision in Bowie, MD. Buying an older DMV home and want to make sure it’s healthy as well as beautiful? Let’s line up the right inspections before you commit — reach out at reggiebutler333@gmail.com or (240) 938-1244.

 

This article is for general information and is not medical or environmental-health advice. For guidance on specific health conditions or hazards, consult a qualified professional.