The science of the home you live in.
Your body responds to a different line than the legal limit. This library measures your water, air, and light against what the health research supports, and tells you where your home stands.
- 43 topics
- 46 guides
- 12 methods
- 10 comparisons
Start with a question
Is my tap water safe to drink? For most people on a US public water system, tap water will not make you sick today, which is a low bar.
Why is the air inside my house worse than outside? Indoor air is often worse than outdoor air because a modern house seals tight and traps what gets made inside it.
Is it bad to sleep with the lights on? Yes, sleeping with the lights on is worse for you than most people assume, and dim light counts.
How do I find out what is actually in my water? Two sources tell you.
Do I need an air purifier? An air purifier helps if your problem is airborne particles: cooking smoke, wildfire haze, traffic soot, pollen, or pet dander.
Do I need a water filter? For most US homes, yes.
The Three Invisibles
- Water What is dissolved in your tap, and the gap between the legal limit and the health line. 26 entries
- Air What you breathe at home all day and all night, measured over a week, not a moment. 11 entries
- Light How the light in your rooms sets, or breaks, your sleep and your daytime alertness. 6 entries
Before you buy anything
Filters, purifiers, ventilation, and the rest, graded against the research. Including the popular fixes that do nothing, and the exposures we do not test because the evidence does not support it.
The legal limit and the health line can sit far apart.
Arsenic
Health-based level 0.004 ppb one-in-a-million cancer riskLegal limit 10 ppb CA + federal MCL; federal MCLG is 0Legal limit 2,500x the health lineSource: CA OEHHA PHG, 2004
PM2.5, annual
Health-based level 5 µg/m³ health-based guideline; no safe floorLegal limit 9.0 µg/m³ federal limit, revised Feb 2024 from 12; under industry litigationLegal limit 1.8x the health line
Nobody authoritative owns the home-environment interpretation layer.
Your utility reports to the legal limit and your home devices report a raw number, but neither tells you what those readings mean for your body.
That is the layer Stasis owns. We grade every reading against peer-reviewed health research rather than the legal limit. That limit is set for what a whole city can feasibly meet, not for the dose your body takes in. Same number, different question: is this allowed, or is this good for you.