Wildfire smoke
Wildfire Smoke episode, 2016-05-07
Daily PM2.5 peaked at 43 µg/m³ near Des Moines across 2 covered metros home to 1.8 million people.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 1.5 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 2.7 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.
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.
What happened, in the record
Qualified frozen evidence supports wildfire smoke as the broad cause for this time-bounded episode.
Sequence: Des Moines (May 7) → Omaha (May 7)
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Des Moines-West Des Moines, IA | 43 µg/m³ | 2.0 | May 7, 2016 | #16 of its top days |
| Omaha-Council Bluffs, NE-IA | 41.5 µg/m³ | 1.9 | May 7, 2016 | #22 of its top days |
"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.
The evidence
EPA AQS monitor qualifier 1
- AQS PM2.5 qualifier RT — Wildfire-U. S. EPA AQS carries an agency-submitted request-exclusion qualifier (RT, Wildfire-U. S.) on 19 PM2.5 samples in the candidate CBSA on 2016-05-07, identifying wildfire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
What remains uncertain
- AQS qualifiers are submitting-agency causal flags and do not by themselves establish EPA concurrence.
- The evidence resolves the broad cause but does not require a named fire, facility, or incident.
- The retained AQS qualifier directly covers Omaha; the supplied evidence does not independently establish the Des Moines portion.
Status and provenance
Research preview: this record carries research-only status and its boundaries, cause, and name may change as evidence review completes. Grouping policy common_sense_root_cause_grouping.v2. The cause label reflects the assembled evidence above, not an IAQng detection formula.