The evidence base and planning tools for owning air-quality emergency (AQE) preparedness and response. The two interactive timelines below are the centerpiece — each entry links to its full, verified reference. Built for agencies, emergency managers, and clinicians.
What this section will include. The evidence base, organized as three threads: a timeline and key references for understanding PM2.5 toxicity (including why wildfire and combustion particles are especially harmful); a timeline and key references for the development of local, low-cost PM2.5 mitigation technology (the path to the PC-fan Corsi-Rosenthal box); and a timeline and key resources for appreciating the increasing frequency and intensity of wildfire emergencies in North America and their impact on public health and health-care resources. The two interactive timelines below already cover these threads; clinical and planning resources will follow.
Air-quality emergencies rarely arrive alone. Wildfire smoke settles in during exactly the hot, stagnant, high-pressure conditions that also drive heat illness — so people are increasingly exposed to extreme heat and extreme PM2.5 at the same time, and the combination is more dangerous than either hazard alone. The effects are synergistic, not merely additive.
In California, coexposure to extreme heat and extreme PM2.5 raised all-cause mortality by about 21% — roughly three times the effect of either exposure alone — and cardiovascular mortality by about 30% (Rahman et al., 2022). A British Columbia study found the same synergistic pattern during wildfire season (Coker et al., 2025); the interaction holds across thirteen U.S. states (Castro et al., 2025) and in wildfire-smoke settings specifically (Uttajug et al., 2024).
The operational implication is direct: AQE preparedness and heat-emergency response should be planned together. A clean-air shelter that isn't also cool — or a cooling center with unfiltered smoke indoors — leaves the compound risk unaddressed. The most protective response delivers filtered and cooled air in the same place, at the same time. This convergence, still underappreciated in 2026, strengthens the case for standing AQE capacity that integrates with existing heat-emergency plans.
Why AQE preparedness matters — the accumulating evidence on what fine-particle pollution does to health (mortality, cardiovascular, mental health, dementia, global burden) alongside the rising frequency, intensity, and toxicity of wildfire smoke. Filter by theme; click any entry for its reference.
Open timeline →The documented lineage of portable air cleaning as a public-health response to smoke — from the 2011 HEPA trial and 2016 frontline commentary through the grassroots CR box, peer-reviewed validation, the PC-fan refinement, and institutional acceptance (EPA, ASHRAE).
Open timeline →Both timelines include their full reference lists with one-click links to each article. Every citation was checked against the publisher record. A consolidated, downloadable reference library is being prepared.
View references →Roles, activation triggers, and a model for how Maine CDC / MEMA and partners can stand up an AQE program.
A template agencies can adapt to call on organizations, volunteers, and the Maine Army National Guard to support preparedness and response.
Who is most at risk during smoke events, and what clinicians should advise.
AQEPREP.ORG · Scientific resources are cited and verified against publisher records.