'Non-detect' doesn't mean the contaminant is absent. It means the lab couldn't find it at the level they tested for. Here's how to read it properly.

Lab reports are full of acronyms that look interchangeable but mean very different things. Here's a clean translation, with examples.

There is no safe level of lead for a child. Even amounts that wouldn't trouble an adult cause measurable cognitive harm. Here's why — and what testing actually tells you.

Asbestos was used in dozens of common building materials until the late 1970s. Here's where it hides and what to test before you renovate.

Some indoor air pollutants matter more during pregnancy than any other time of life. Here's a focused testing list for the second and third trimester.

Before you swing a hammer in any pre-1980 home, run this short list of tests. They're the difference between a clean renovation and a contamination event.

You can spend hundreds on a baby monitor and nothing on what your baby actually breathes and drinks. Here's the testing list to run while the room is still empty.

Federal law requires sellers and landlords to disclose known lead paint hazards in homes built before 1978. Here's what that disclosure actually covers — and what it doesn't.

Elevated indoor mold counts almost never mean what the internet tells you they mean. Here's a calm, step-by-step way to interpret your air sample.

PFAS are a class of thousands of chemicals that don't break down in the environment or in your body. Here's what they are, where they come from, and how to find out if they're in your water.

Volatile organic compounds off-gas from everyday products and can cause real health symptoms. Here's how to spot them and decide whether to test.

The two main types of mold tests answer different questions. Here's how to pick the right one before you spend on a remediation quote.

EPA studies have found indoor pollutant levels can be two to five times higher than outdoor levels. Here's why, and what to do about it.

Mold can begin growing in as little as 24 to 48 hours after water intrusion. Here's how to act in the window where you can still prevent it.

City water passes federal tests — but that doesn't mean it's contaminant-free. Here's what utilities measure, what they miss, and what to test for at home.

Well water isn't regulated by the EPA — that's on you. Here's the testing cadence every well owner should follow, plus what to do when something comes back high.

Radon is invisible, odorless, and the second-leading cause of lung cancer in the U.S. Every home should be tested at least once.

'Toxic black mold' is one of the most misunderstood phrases in home health. Here's what it actually refers to and how worried you should be.