Mixed causes
2004-07-23 multiple material causes episode affecting Deltona-Daytona Beach-Ormond Beach, FL, Lakeland-Winter Haven, FL, Palm Bay-Melbourne-Titusville, FL, North Port-Sarasota-Bradenton, FL, Tampa-St. Petersburg-Clearwater, FL
Daily PM2.5 peaked at 36.2 µg/m³ near Tampa across 5 covered metros home to 6.6 million people. 2 metros 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 ≈ 1.1 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 7.5 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 multiple material contributors to this event: wildfire smoke and transported or windblown dust.
Sequence: Tampa (Jul 23) → Lakeland (Jul 23) → North Port (Jul 23) → Deltona (Jul 23) → Palm Bay (Jul 23)
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Tampa-St. Petersburg-Clearwater, FL | 36.2 µg/m³ | 1.6 | Jul 23, 2004 | #18 of its top days |
| Lakeland-Winter Haven, FL | 32.6 µg/m³ | 1.5 | Jul 23, 2004 | #8 of its top days |
| North Port-Sarasota-Bradenton, FL | 31.3 µg/m³ | 1.4 | Jul 23, 2004 | #10 of its top days |
| Deltona-Daytona Beach-Ormond Beach, FL | 29.1 µg/m³ | 1.3 | Jul 23, 2004 | #12 of its top days |
| Palm Bay-Melbourne-Titusville, FL | 23.1 µg/m³ | 1.1 | Jul 23, 2004 | #20 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 4
- AQS PM2.5 qualifier RA — African Dust. EPA AQS carries an agency-submitted request-exclusion qualifier (RA, African Dust.) on 1 PM2.5 sample in the candidate CBSA on 2004-07-23, identifying windblown or transported dust as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
- AQS PM2.5 qualifier RA — African Dust. EPA AQS carries an agency-submitted request-exclusion qualifier (RA, African Dust.) on 1 PM2.5 sample in the candidate CBSA on 2004-07-23, identifying windblown or transported dust as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
- AQS PM2.5 qualifier RA — African Dust. EPA AQS carries an agency-submitted request-exclusion qualifier (RA, African Dust.) on 1 PM2.5 sample in the candidate CBSA on 2004-07-23, identifying windblown or transported dust as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
- AQS PM2.5 qualifier RA — African Dust. EPA AQS carries an agency-submitted request-exclusion qualifier (RA, African Dust.) on 1 PM2.5 sample in the candidate CBSA on 2004-07-23, identifying windblown or transported dust as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
Agency and publisher pages 1
- Estimating the impact of the 2004 Alaskan forest fires on episodic particulate matter pollution over the eastern United States through assimilation of satellite-derived aerosol optical depths in a regional air quality model Analysis of measured and modeled PM2.5 attributed a 24–42% median enhancement across the eastern United States during 19–23 July 2004 to transported particulate pollution from Alaskan forest fires; the Florida event occurred on 23 July within that assessed period.
What remains uncertain
- AQS qualifiers are submitting-agency causal flags and do not by themselves establish EPA concurrence.
- The relative contribution of each supported cause is not quantified.
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.