The Exposure in Your Home
You spend the overwhelming majority of your life indoors, and indoor air is frequently more contaminated than the air outside. This is the part of the subject with the best return for the least effort, and it is the part people skip to get to supplements.
Air
Indoor air accumulates whatever comes off furnishings, flooring, paint, electronics, cleaning products and cooking. In a well-sealed modern home it has nowhere to go.
Cooking is the largest single source for most households. Gas hobs produce nitrogen dioxide directly. Frying and roasting produce fine particulates regardless of fuel. Extraction while cooking, vented outside rather than recirculating, does more for indoor air quality than any purifier.
Ventilate deliberately. Windows open for a few minutes, twice a day, even in winter. It is the cheapest intervention available and it works.
Scented products are an air quality decision. Plug-ins, sprays and candles add volatile compounds continuously. Removing them is free and removes a daily exposure.
Dust
Household dust is where a great deal of the semi-volatile load ends up. Flame retardants from furniture and electronics, plasticizers, PFAS from textiles, and particles from everything in the room.
- Vacuum with a HEPA filter rather than redistributing it
- Damp cloth rather than dry dusting, which mostly moves dust into the air
- Take shoes off at the door, which is the single easiest reduction in what comes in
- Pay more attention to soft furnishings, which hold more than hard surfaces
Water
This is the one genuinely worth checking rather than guessing, because it varies enormously by locality and the answer is public.
Your local water supplier publishes an annual quality report, and the EPA requires it. Read yours before buying a filter, because the right filter depends entirely on what is actually in your water. A carbon filter addresses a different set of problems to reverse osmosis.
Older housing
Lead service lines and lead solder remain in parts of the housing stock. If your home predates the mid eighties, this is worth establishing rather than assuming, and testing is inexpensive.
If anyone in the household is pregnant or there are young children, move this up the list.
Where it is not worth the money
Air purifiers in every room, when ventilation and extraction are not sorted. Alkaline or structured water, which is marketing. Whole-house systems bought before reading the water report. Anything described as removing toxins from your home without naming which.
Two things that genuinely are urgent
- Carbon monoxide. A working alarm on every floor. This is not a long-term risk reduction question, it kills people every year.
- Radon. The second leading cause of lung cancer in the United States. It is odourless, it varies by geography, test kits are cheap, and parts of the country have meaningful levels. Worth testing once and then forgetting about.
Both of these have a far stronger evidence base than anything else on this page, and both get less attention than microplastics.
