Lead in Drinking Water
The EPA estimates 4 million lead service lines are still in active use across the U.S. Here’s how lead actually gets into your water, why orthophosphate isn’t a permanent fix, and how to check your own service line.
Built to Heal
In 1984, Dr. Roger Ulrich proved that hospital patients with a window view of trees recovered faster than those staring at a brick wall. Forty years later, that one study is reshaping how we think about every space we live in.
The Humidity Sweet Spot
Indoor humidity has a sweet spot between 30% and 50% — and most homes are nowhere near it. The science behind the Scofield-Sterling chart, the mold problem, and how to dial it in.
How to Pick the Right Air Purifier
Don't buy an expensive fan. A complete guide to HEPA, CADR, room sizing, and the AHAM Verifide seal — plus a free tool to pick the unit that actually fits your room.
Does Air Quality Impact Chess Performance?
A study of over 30,000 chess moves found that even modest increases in indoor PM2.5 significantly raised error rates — and the implications extend far beyond the chessboard.
Mold in Homes
Mold is one of the most prevalent and most underdiagnosed indoor environmental problems. Here's how to think about it, test for it, and control it.
Should you be worried about Radon?
Radon is the second leading cause of lung cancer in the U.S. — and most homes have never been tested. If you live in Minnesota or Wisconsin, this one is especially worth reading.
Why home location matters more than you think
Where your home sits — near an airport, a highway, or a flight path — directly shapes the air you breathe inside. Location isn't just a real estate decision.
The kitchen
The kitchen is one of the most polluted rooms in the average home. Gas stoves, synthetic surfaces, and cleaning products all contribute — and most people have no idea.
Let there be the (right) light
The type of light you're exposed to — and when — has a profound effect on sleep, hormones, and mood. Most homes are lit in ways that quietly work against your biology.
Preparing the home for a baby
Babies are far more sensitive to environmental toxins than adults. Before the nursery goes up, here's what to know about air quality, VOCs, EMFs, and chemicals in the home.
Should you drink tap water?
Most tap water in the U.S. meets legal standards — but legal doesn't mean safe. Here's what's actually in your water and why the gap between 'legal' and 'healthy' matters.
How to optimize your bedroom for restful sleep
Your bedroom may be quietly disrupting your sleep. From RF radiation to blue light exposure, here's what we measure and what to change to get deeper, more restorative rest.
How painting impacts your indoor air quality
A fresh coat of paint might make your walls look better — but it can make your air significantly worse. VOC off-gassing from paint is one of the most common issues we find during assessments.
The German practice of Lüften
Germans have a word for opening your windows to flush out stale indoor air: Lüften. It's a simple, free habit that can dramatically improve your home's air quality — and most Americans never do it.