Air-pollution health effects split into two broad regimes. Acute effects come from short-duration high exposure: an asthma attack triggered by today's pollen, a headache from a cooking-related CO2 peak, irritation from a cleaning-product VOC pulse. Cumulative effects come from sustained low-to-moderate exposure over years: cardiovascular mortality, lung-function deficit, cognitive decline. The two regimes have different drivers and respond to different interventions.
The PM2.5 literature is unusually clear on the distinction. The Lancet Global Burden of Disease analysis attributes the bulk of PM-related deaths to long-term exposure: the integral of concentration over years. The AHA scientific statement quantifies cardiovascular mortality risk per 10 µg/m³ of long-term average. Acute spikes (wildfire smoke days, peak winter inversions) produce measurable but smaller bumps in same-week hospital admissions.
For most household-level decisions, both regimes are visible in your data. The dashboard tracks both: a daily-peak view answers acute questions (was today bad?), a 30-day or 365-day average view answers cumulative ones (is my home structurally dirtier than it should be?). The relevant threshold differs by regime: the EPA AQI 24-hour PM2.5 standard (35 µg/m³) is an acute number; the WHO 2021 annual guideline (5 µg/m³) is a cumulative one.
For asthma and other conditions with sharp triggers, acute spikes dominate. For cardiovascular and cancer risks, cumulative averages dominate. For cognitive performance, both matter (see productivity). The AI tags each notification with its regime so you can prioritize: a sustained moderate elevation is structurally different from a brief sharp peak, even when the numbers look similar.
