Prescribed fire
2005-10-20 prescribed-fire smoke episode affecting Columbia, SC, Charlotte-Concord-Gastonia, NC-SC
Daily PM2.5 peaked at 40.5 µg/m³ near Charlotte across 2 covered metros home to 3.8 million people.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 1.3 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 5.0 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 prescribed-fire smoke as the broad root cause.
Sequence: Columbia (Oct 20) → Charlotte (Oct 21)
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Charlotte-Concord-Gastonia, NC-SC | 40.5 µg/m³ | 1.8 | Oct 21, 2005 | #24 of its top days |
| Columbia, SC | 37.7 µg/m³ | 1.7 | Oct 20, 2005 | #21 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 2
- AQS PM2.5 qualifier RM — Prescribed Fire. EPA AQS carries an agency-submitted request-exclusion qualifier (RM, Prescribed Fire.) on 2 PM2.5 samples in the candidate CBSA on 2005-10-21, identifying prescribed-fire smoke as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
- AQS PM2.5 qualifier RM — Prescribed Fire. EPA AQS carries an agency-submitted request-exclusion qualifier (RM, Prescribed Fire.) on 2 PM2.5 samples in the candidate CBSA on 2005-10-20, identifying prescribed-fire 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.