{
  "slug": "air-quality-exposure-equivalent",
  "title": "Air Quality Exposure Equivalent Calculator",
  "heading": "Air Quality Cigarette-Equivalent Calculator",
  "category": "fitness-health",
  "url": "https://www.revenuelab.fyi/toolbox/air-quality-exposure-equivalent",
  "summary": "Convert PM2.5 air pollution exposure into a cigarette-equivalent for intuitive comparison.",
  "description": "PM2.5 (fine particulate matter under 2.5 microns) is the pollutant most strongly linked to cardiovascular and respiratory harm from both wildfire smoke and everyday air pollution, and its health effects scale roughly with cumulative exposure. Berkeley Earth popularized a rule of thumb — 22 µg/m³ of sustained PM2.5 exposure over 24 hours is roughly equivalent to smoking one cigarette in inhaled particulate burden — as an intuitive translation of an abstract air quality number into something people immediately understand. This calculator applies that ratio, scaled by your actual exposure duration and concentration, and also reports the EPA AQI category so you can see both the intuitive comparison and the official health guidance side by side.",
  "formula": "Cigarette-equivalent = (PM2.5 µg/m³ × exposure hours ÷ 24) ÷ 22. AQI category from EPA PM2.5 breakpoints.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=air-quality-exposure-equivalent",
  "inputs": [
    {
      "id": "pm25",
      "label": "PM2.5 concentration",
      "kind": "number",
      "hint": null,
      "default": 75,
      "unit": "µg/m³",
      "min": 0,
      "max": 600
    },
    {
      "id": "hours",
      "label": "Exposure duration",
      "kind": "number",
      "hint": null,
      "default": 8,
      "unit": "hours",
      "min": 0.5,
      "max": 24
    }
  ],
  "outputs": [
    {
      "id": "cigEquiv",
      "label": "Cigarette-equivalent exposure",
      "format": "decimal",
      "hint": null,
      "primary": true
    },
    {
      "id": "category",
      "label": "EPA AQI category (PM2.5)",
      "format": "raw",
      "hint": null,
      "primary": false
    },
    {
      "id": "dailyDose",
      "label": "24-hr equivalent PM2.5 dose",
      "format": "number",
      "hint": null,
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "PM2.5 concentration: 75 µg/m³",
      "Exposure duration: 8 hours"
    ],
    "outputs": [
      "Cigarette-equivalent exposure: 1.14",
      "EPA AQI category (PM2.5): Unhealthy",
      "24-hr equivalent PM2.5 dose: 25"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter pm2.5 concentration (µg/m³).",
      "Enter exposure duration (hours).",
      "Read your cigarette-equivalent exposure on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "pm25": 45,
        "hours": 4.8
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "pm25": 75,
        "hours": 8
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "pm25": 120,
        "hours": 12.8
      }
    }
  ],
  "limitations": [
    "Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.",
    "Results do not account for medical conditions, medication, or pregnancy.",
    "Use this as a directional reference, not a diagnosis — talk to a clinician before acting on it."
  ],
  "faq": [
    {
      "q": "How reliable is the cigarette-equivalent comparison?",
      "a": "It's a rough intuitive translation, not a precise toxicological equivalence — cigarette smoke and ambient PM2.5 differ in particle composition and co-pollutants. Berkeley Earth's ratio is widely cited by air quality scientists as a useful gut-check, not a clinical dosage measurement."
    },
    {
      "q": "What PM2.5 levels are common during wildfire smoke events?",
      "a": "Smoke-impacted cities regularly see spikes of 150-300+ µg/m³ during active fire events, occasionally exceeding 500 µg/m³ in the worst hours, compared to a typical 'good' day of under 12 µg/m³ in most US cities."
    },
    {
      "q": "Should I trust indoor air during a bad outdoor air quality day?",
      "a": "Indoor PM2.5 is usually 30-70% of outdoor levels with windows closed and no filtration, but a HEPA air purifier or a well-sealed HVAC system with a MERV 13+ filter can cut indoor PM2.5 by 80%+ relative to outdoor levels during smoke events."
    },
    {
      "q": "Why does exposure duration matter as much as concentration?",
      "a": "Cumulative particulate dose is roughly concentration times time, so 8 hours at 75 µg/m³ delivers a similar dose to about 2 hours at 300 µg/m³. Short, intense exposure and long, moderate exposure can be comparably harmful."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/uv-exposure-burn-time",
    "https://www.revenuelab.fyi/toolbox/carbon-footprint-home"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Air Quality Exposure Equivalent Calculator (https://www.revenuelab.fyi/toolbox/air-quality-exposure-equivalent)"
}