Daily PM2.5 peaked at 34.2 µg/m³ near Orlando across
1 covered metro home to 2.9 million people.
Counting the extra PM2.5 above each metro's typical day, this event handed the
average affected resident ≈ 1.2 cigarettes.
Across everyone living in the affected metros, that is the collective equivalent of
≈ 3.6 million cigarettes.
An awareness illustration of outdoor exposure at 22 µg/m³
per cigarette (Berkeley Earth), counting only the event's ranked days; not a
medical dose.
Why we think this happened
The basis for “Wildfire smoke”
The same-day Melbourne discussion reports that haze and smoke from scattered brush fires were obscuring east-central Florida skies while the Orlando episode was measured. The date, place, and stated limitations support possible confidence only.
PossibleThis is a transparent hypothesis supported by limited evidence or an explicit inference, not a definitive attribution.
National Weather Service Melbourne via Iowa Environmental Mesonet · Feb 10, 2000official
The same-day Melbourne discussion reports that haze and smoke from scattered brush fires were obscuring east-central Florida skies while the Orlando episode was measured.
A cause is more convincing when the record connects three things: something happened,
the air mass moved toward the region, and local instruments responded. Here is how much
of that chain is documented for this event.
The same-day Melbourne discussion reports that haze and smoke from scattered brush fires were obscuring east-central Florida skies while the Orlando episode was measured.
The retained record does not yet show how air traveled from the proposed source to
these metros. A trajectory replay or dated plume analysis belongs here.
Research gap
3
Local response
34.2 µg/m³ near Orlando
EPA monitors recorded the event across 1 metro.
The peak daily concentration is roughly 1.6 cigarette-equivalents at the outdoor daily rate.
Before, during, and after the episode: nearby pollutant monitors and surface-weather
stations show what changed. This context tests the “Wildfire smoke” explanation; it does
not assign the cause by itself.
Source: U.S. EPA AirData daily observations and, where available, nearby ASOS/AWOS
surface observations. Values are descriptive medians over the retained monitor set;
missing measurements remain missing. Transport and source evidence remain separate
layers because this instrument pattern does not assign a cause by itself.
Measured daily PM2.5 at EPA monitors, as cigarette-equivalents
EPA monitors sit in metro areas, so the colour clusters there. Land between and beyond
them is unmeasured, not clean: this map shows where IAQng has readings, not the extent
of the smoke.
—
Episode peak
--cigarettes
The smoke map's scale, replayed over this event: the surface interpolates between
covered metros' daily records, framed to the affected region. Hover for a reading,
click a metro to pin it to the card. Days a monitor did not report draw nothing.
Select a metro on the map to see nearby cameras. Where an operator archive reaches
the event, drag the divider to compare two moments, adjust either date and time, or
play the available event-day frames. Camera imagery is visual context, not an
air-quality measurement or proof of smoke.
No useful public camera views are currently available within 80 km of this metro.
"Cigarettes, whole event" totals a metro's ranked event days at 22 µg/m³ per
cigarette: what a person outdoors there breathed across the event, as the
illustration. "All-time standing" is where this episode's days sit in each metro's
ranked record (worst-area measure, since 1999). Full local context is on each
metro's Air Records page.
Public evidence library
What supports this account
Each card states what a source supports—and what it does not. Official records, research, reporting, community observations, and transparent inferences remain visibly different kinds of evidence.
1 retained source
Official record
Area Forecast Discussion: haze and smoke from scattered regional brush fires
National Weather Service Melbourne via Iowa Environmental Mesonet
The same-day Melbourne discussion reports that haze and smoke from scattered brush fires were obscuring east-central Florida skies while the Orlando episode was measured.
What it supports
An official source supports the attributed cause for the stated place and dates.
Limit
The discussion does not identify the fires or establish whether each fire was wild, agricultural, or prescribed; wildfire_smoke is therefore a broad wildland-fire category at possible confidence.
What remains uncertain
The discussion does not identify the fires or establish whether each fire was wild, agricultural, or prescribed; wildfire_smoke is therefore a broad wildland-fire category at possible confidence.
Status and provenance
PossibleThis is a transparent hypothesis supported by limited evidence or an explicit inference, not a definitive attribution.
This episode was grouped from the monitor record by the catalog pipeline and given
its cause from the evidence listed above. It has not been individually reviewed and
signed off, so its boundaries, cause, and name may change as evidence accumulates.
Grouping policy common_sense_root_cause_grouping.v2. The cause label reflects the
assembled evidence above, not an IAQng detection formula. If it is wrong,
tell us.