Mixed causes EPA monitor flag
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.
Why we think this happened
Qualified frozen evidence supports multiple material contributors to this event: wildfire smoke and transported or windblown dust.
EPA monitor flag EPA attached an exceptional-event qualifier to the affected samples. The agency flagged the measurement itself; no separate agency record describes the event.
U.S. EPA Air Quality System and the submitting air monitoring agency · Jul 23, 2004 official
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.
U.S. EPA Air Quality System and the submitting air monitoring agency · Jul 23, 2004 official
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.
U.S. EPA Air Quality System and the submitting air monitoring agency · Jul 23, 2004 official
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.
See every retained source and limitation ↓
Sequence: Tampa (Jul 23) → Lakeland (Jul 23) → North Port (Jul 23) → Deltona (Jul 23) → Palm Bay (Jul 23)
Evidence path
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.
Source or mechanism
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…
View supporting source ↗Air-mass movement
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…
View transport source ↗Local response
EPA monitors recorded the event across 5 metros. The peak daily concentration is roughly 1.6 cigarette-equivalents at the outdoor daily rate.
Inspect the pollutant and weather signals ↓Event autopsy
Before, during, and after the episode: nearby pollutant monitors and surface-weather stations show what changed. This context tests the “Mixed causes” explanation; it does not assign the cause by itself.
Deltona-Daytona Beach-Ormond Beach, FL
Monitor comparison window 2004-07-20 to 2004-07-26 · PM2.5 target: DAYTONA BLIND SERVICES
145% above nearby days
31% higher than surrounding days
145% higher than surrounding days
31% higher than surrounding days
36% higher than surrounding days
Lakeland-Winter Haven, FL
Monitor comparison window 2004-07-20 to 2004-07-26 · PM2.5 target: Baptist Childrens' Home
264% above nearby days
79% higher than surrounding days
264% higher than surrounding days
79% higher than surrounding days
About the same as surrounding days
19% higher than surrounding days
Palm Bay-Melbourne-Titusville, FL
Monitor comparison window 2004-07-20 to 2004-07-26 · PM2.5 target: Melbourne
196% above nearby days
25% higher than surrounding days
196% higher than surrounding days
25% higher than surrounding days
17% higher than surrounding days
North Port-Sarasota-Bradenton, FL
Monitor comparison window 2004-07-20 to 2004-07-26 · PM2.5 target: G.T. BRAY PARK
338% above nearby days
77% higher than surrounding days
338% higher than surrounding days
77% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
408% higher than surrounding days
46% higher than surrounding days
Tampa-St. Petersburg-Clearwater, FL
Monitor comparison window 2004-07-20 to 2004-07-26 · PM2.5 target: Morrison Ave
94% above nearby days
67% higher than surrounding days
94% higher than surrounding days
67% higher than surrounding days
13% higher than surrounding days
34% higher than surrounding days
129% higher than surrounding days
25% higher than surrounding days
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.
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.
Views from the selected metro
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.
| 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.
Public evidence library
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.
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.
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.
EPA monitor flag EPA attached an exceptional-event qualifier to the affected samples. The agency flagged the measurement itself; no separate agency record describes the event.
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.