Wildfire smoke
2000-10-26 wildfire smoke episode affecting Greenville-Anderson-Mauldin, SC, Atlanta-Sandy Springs-Roswell, GA, Chattanooga, TN-GA, Knoxville, TN
Daily PM2.5 peaked at 57 µg/m³ near Knoxville across 4 covered metros home to 9.0 million people. 1 metro placed a top-ten day in their record.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 2.0 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 18 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 causal evidence supports wildfire smoke as the broad root cause.
Sequence: Greenville (Oct 26) → Knoxville (Oct 27) → Atlanta (Oct 27) → Chattanooga (Oct 27)
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Knoxville, TN | 57 µg/m³ | 2.6 | Oct 27, 2000 | #13 of its top days |
| Atlanta-Sandy Springs-Roswell, GA | 54 µg/m³ | 2.5 | Oct 27, 2000 | #22 of its top days |
| Chattanooga, TN-GA | 49.5 µg/m³ | 2.3 | Oct 27, 2000 | #10 of its top days |
| Greenville-Anderson-Mauldin, SC | 41.3 µg/m³ | 3.6 | Oct 26, 2000 | #15 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 E — Forest Fire. EPA AQS carries an agency-submitted request-exclusion qualifier (E, Forest Fire.) on 3 PM2.5 samples in the candidate CBSA on 2000-10-27, 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.
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.