Practical System Evidence: Traditional / Experiential — These recommendations are based on established horticultural practice and practical growing experience, not a clinical health claim.
Air, Water & Natural Home
The environment you breathe, drink, and sleep in — practical low-tox improvements ranked by impact.
Guides
Evidence: Established — That HEPA-class filtration lowers indoor PM2.5 is settled measurement science, and CADR is a standardized AHAM test; the establishment claim covers particle reduction and sizing math, not health outcomes from any specific device.
Choosing an Air Purifier for Wildfire Smoke (the CADR Math That Matters)
Evidence: Supported — Darkness, quiet, and cool temperature are consistently associated with better sleep in human studies; specific product interventions carry smaller, more variable evidence.
A Better Sleep Environment: Light, Sound, Temperature, and Air
Evidence: Established — The WHO treats environmental noise as a documented public-health concern, with consistent evidence linking chronic noise exposure to sleep disturbance and cardiovascular risk.
Environmental Noise, Sleep, and Health: What the Evidence Actually Says
Evidence: Supported — EPA chamber studies measured DIY box-fan cleaners with MERV-13 filters removing smoke-sized particles at rates comparable to commercial HEPA purifiers; the evidence is controlled-chamber particle removal, not home health-outcome trials.
The CR Box: a ~$70 DIY Air Purifier That Actually Works
Practical System Evidence: Established — Plant temperature tolerances, frost injury, water needs, and safe working conditions are established horticultural principles.
How to Use a Ten-Day Forecast for Planting
Practical System Evidence: Traditional / Experiential — Layered perennial growing combines established horticulture with site-specific design traditions; outcomes depend heavily on climate, plants, and management.
Starting a Small Food Forest Without Overplanning It
Evidence: Established — Staying indoors, sealing the envelope, and filtering recirculated air during smoke events is consistent EPA/CDC guidance grounded in well-understood particle physics; the uncertainty is in individual health-effect magnitudes, not in whether filtration lowers indoor PM2.5.
Wildfire Smoke Indoors: What Actually Helps
Related research
WHO guidelines identify environmental noise as a significant public-health risk
Chronic exposure to environmental noise above recommended levels is associated with sleep disturbance, annoyance, and increased risk of ischaemic heart disease; WHO issues exposure-limit recommendations for road, rail, aircraft, wind-turbine, and leisure noise.
EPA chamber testing: DIY box-fan air cleaners removed wildfire-smoke particles at rates comparable to commercial purifiers
Box-fan air cleaners built with MERV-13 filters produced clean-air delivery for smoke-sized particles comparable to commercial portable HEPA purifiers, at a fraction of the purchase price; multi-filter (CR box) designs outperformed single-filter designs, and fan-motor temperature testing found no fire-safety concern with filters attached.
What remains uncertain
Every topic on this site has open questions — that's how science
works. Individual guides call out specific uncertainties, and our
methodology explains how we grade what we
publish.