Fireworks EPA monitor flag
Daily PM2.5 peaked at 123.5 µg/m³ near Des Moines across 6 covered metros home to 6.3 million people. 1 metro recorded their worst day on record; 4 placed a top-ten day.
Counting the extra PM2.5 above each metro's typical day, this event handed the average affected resident ≈ 3.7 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 23 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
Supplied qualified evidence supports fireworks as the root cause. The grouping includes only events linked by explicit shared episode evidence; otherwise this remains a single-event episode.
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 5, 2020 official
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 22 PM2.5 samples in the candidate CBSA on 2020-07-05, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
U.S. EPA Air Quality System and the submitting air monitoring agency · Jul 4, 2020 official
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 11 PM2.5 samples in the candidate CBSA on 2020-07-04, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
U.S. EPA Air Quality System and the submitting air monitoring agency · Jul 4, 2020 official
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 4 PM2.5 samples in the candidate CBSA on 2020-07-04, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
See every retained source and limitation ↓
Sequence: Des Moines (Jul 4) → Kansas City (Jul 4) → Omaha (Jul 4) → Greenville (Jul 4) → Wichita (Jul 4) → Chattanooga (Jul 5)
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 informational qualifier (IH, Fireworks.) on 22 PM2.5 samples in the candidate CBSA on 2020-07-05, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag,…
View supporting source ↗Air-mass movement
The retained record does not yet show how air traveled from the proposed source to these metros. A trajectory replay or dated plume analysis belongs here.
Local response
Iowa DNR lists July 4 and 5, 2020 PM2.5 exceedances at the Des Moines Polk County Health monitor, including 108.7 µg/m3 on July 4.
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 “Fireworks” explanation; it does not assign the cause by itself.
Des Moines-West Des Moines, IA
Monitor comparison window 2020-07-01 to 2020-07-08 · PM2.5 target: CARPENTER
473% above nearby days
21% lower than surrounding days
126% higher than surrounding days
473% higher than surrounding days
126% higher than surrounding days
62% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
21% lower than surrounding days
Omaha-Council Bluffs, NE-IA
Monitor comparison window 2020-07-01 to 2020-07-08 · PM2.5 target: ON TOP OF ELEMENTARY SCHOOL
316% above nearby days
17% lower than surrounding days
58% higher than surrounding days
316% higher than surrounding days
58% higher than surrounding days
8% higher than surrounding days
8% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
17% lower than surrounding days
Kansas City, MO-KS
Monitor comparison window 2020-07-01 to 2020-07-08 · PM2.5 target: Troost
105% above nearby days
11% higher than surrounding days
32% higher than surrounding days
105% higher than surrounding days
32% higher than surrounding days
About the same as surrounding days
12% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
6% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
11% higher than surrounding days
Wichita, KS
Monitor comparison window 2020-07-01 to 2020-07-08 · PM2.5 target: WICHITA HD
14% above nearby days
29% higher than surrounding days
14% higher than surrounding days
29% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
Greenville-Anderson-Mauldin, SC
Monitor comparison window 2020-07-01 to 2020-07-08 · PM2.5 target: Greenville ESC
334% above nearby days
173% higher than surrounding days
334% higher than surrounding days
173% higher than surrounding days
About the same as surrounding days
194% higher than surrounding days
14% higher than surrounding days
Chattanooga, TN-GA
Monitor comparison window 2020-07-01 to 2020-07-08 · PM2.5 target: EAST RIDGE CITY HALL
312% above nearby days
312% higher than surrounding days
7% 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 |
|---|---|---|---|---|
| Des Moines-West Des Moines, IA | 123.5 µg/m³ | 8.4 | Jul 4, 2020 | Worst day on record |
| Kansas City, MO-KS | 66.6 µg/m³ | 4.9 | Jul 4, 2020 | #2 of its top days |
| Omaha-Council Bluffs, NE-IA | 64.5 µg/m³ | 5.4 | Jul 5, 2020 | #3 of its top days |
| Chattanooga, TN-GA | 55.9 µg/m³ | 2.5 | Jul 5, 2020 | #5 of its top days |
| Greenville-Anderson-Mauldin, SC | 41.4 µg/m³ | 1.9 | Jul 4, 2020 | #14 of its top days |
| Wichita, KS | 38 µg/m³ | 1.7 | Jul 4, 2020 | #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.
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 IH — Fireworks.
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 22 PM2.5 samples in the candidate CBSA on 2020-07-05, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
AQS PM2.5 qualifier IH — Fireworks.
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 11 PM2.5 samples in the candidate CBSA on 2020-07-04, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
AQS PM2.5 qualifier IH — Fireworks.
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 4 PM2.5 samples in the candidate CBSA on 2020-07-04, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
AQS PM2.5 qualifier IH — Fireworks.
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 3 PM2.5 samples in the candidate CBSA on 2020-07-05, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
AQS PM2.5 qualifier IH — Fireworks.
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 48 PM2.5 samples in the candidate CBSA on 2020-07-04, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
AQS PM2.5 qualifier IH — Fireworks.
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 51 PM2.5 samples in the candidate CBSA on 2020-07-05, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
AQS PM2.5 qualifier IH — Fireworks.
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 4 PM2.5 samples in the candidate CBSA on 2020-07-04, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
AQS PM2.5 qualifier IH — Fireworks.
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 6 PM2.5 samples in the candidate CBSA on 2020-07-04, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
AQS PM2.5 qualifier IH — Fireworks.
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 14 PM2.5 samples in the candidate CBSA on 2020-07-05, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
AQS PM2.5 qualifier IH — Fireworks.
EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 8 PM2.5 samples in the candidate CBSA on 2020-07-05, identifying fireworks as affecting the samples. An informational qualifier is an official submitting-agency flag, not a request for exclusion or an EPA-concurred determination.
Iowa Exceedances of the National Ambient Air Quality Standards
Iowa DNR lists July 4 and 5, 2020 PM2.5 exceedances at the Des Moines Polk County Health monitor, including 108.7 µg/m3 on July 4.
The City of Des Moines reported that the Iowa DNR's July 4 weekend poor-air-quality advisory for Des Moines stemmed from fireworks usage.
Air quality advisory issued for Kansas City because of lingering firework smoke
The opened report cites a National Weather Service advisory stating that July Fourth fireworks smoke was trapped near the ground by a shallow inversion, producing very unhealthy Kansas City air on July 5. This directly supports fireworks for the Kansas City member but not independently for Wichita.
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.