Fireworks
Fireworks episode, 2015-07-04 through 2015-07-05
Daily PM2.5 peaked at 117.8 µg/m³ near Chicago across 6 covered metros home to 21 million people. 4 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 ≈ 3.7 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 78 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 fireworks as the broad cause for this time-bounded episode and supports grouping 4 overlapping event records. Qualified frozen evidence supports fireworks as the broad cause for this time-bounded episode and supports grouping 4 overlapping event records. Qualified frozen evidence supports fireworks as the broad cause for this time-bounded episode and supports grouping 4 overlapping event records. Qualified frozen evidence supports fireworks as the broad cause for this time-bounded episode and supports grouping 4 overlapping event records.
Sequence: Louisville/Jefferson County (Jul 4) → St. Louis (Jul 4) → Chicago (Jul 5) → Seattle (Jul 5) → Indianapolis (Jul 5) → Grand Rapids (Jul 5)
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Chicago-Naperville-Elgin, IL-IN-WI | 117.8 µg/m³ | 5.4 | Jul 5, 2015 | #5 of its top days |
| Seattle-Tacoma-Bellevue, WA | 77.3 µg/m³ | 3.5 | Jul 5, 2015 | #17 of its top days |
| Indianapolis-Carmel-Anderson, IN | 66.4 µg/m³ | 3.0 | Jul 5, 2015 | #5 of its top days |
| Louisville/Jefferson County, KY-IN | 60.2 µg/m³ | 2.7 | Jul 4, 2015 | #6 of its top days |
| Grand Rapids-Wyoming, MI | 58.5 µg/m³ | 2.7 | Jul 5, 2015 | #9 of its top days |
| St. Louis, MO-IL | 49.8 µg/m³ | 4.4 | Jul 5, 2015 | #19 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 13
- AQS PM2.5 qualifier RH — Fireworks. EPA AQS carries an agency-submitted request-exclusion qualifier (RH, Fireworks.) on 7 PM2.5 samples in the candidate CBSA on 2015-07-05, identifying fireworks 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 IH — Fireworks. EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 18 PM2.5 samples in the candidate CBSA on 2015-07-04, 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 42 PM2.5 samples in the candidate CBSA on 2015-07-05, 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 RH — Fireworks. EPA AQS carries an agency-submitted request-exclusion qualifier (RH, Fireworks.) on 16 PM2.5 samples in the candidate CBSA on 2015-07-04, identifying fireworks 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 IH — Fireworks. EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 15 PM2.5 samples in the candidate CBSA on 2015-07-04, 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 2015-07-05, 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 2015-07-04, 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 RH — Fireworks. EPA AQS carries an agency-submitted request-exclusion qualifier (RH, Fireworks.) on 26 PM2.5 samples in the candidate CBSA on 2015-07-05, identifying fireworks 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 IH — Fireworks. EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 37 PM2.5 samples in the candidate CBSA on 2015-07-05, 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 RH — Fireworks. EPA AQS carries an agency-submitted request-exclusion qualifier (RH, Fireworks.) on 17 PM2.5 samples in the candidate CBSA on 2015-07-05, identifying fireworks 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 RH — Fireworks. EPA AQS carries an agency-submitted request-exclusion qualifier (RH, Fireworks.) on 16 PM2.5 samples in the candidate CBSA on 2015-07-05, identifying fireworks 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 IH — Fireworks. EPA AQS carries an agency-submitted informational qualifier (IH, Fireworks.) on 23 PM2.5 samples in the candidate CBSA on 2015-07-05, 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.
- +1 more EPA AQS records on file
Agency and publisher pages 3
- Illinois Air Quality Report 2015 Illinois EPA's 2015 annual report identifies Fourth of July fireworks as causing elevated PM2.5 concentrations in localized areas, supporting a fireworks source for the Chicago portion of this event.
- Canadian wildfires pushing smoke across Puget Sound Contemporaneous reporting identified British Columbia wildfires as the source of haze across Puget Sound and reported pollution spikes late Sunday night, overlapping the event date.
- Effects of Independence Day fireworks on atmospheric concentrations of fine particulate matter in the United States A 315-site U.S. analysis found PM2.5 is typically elevated on July 4 evening and July 5 morning, but it does not attribute the St. Louis event specifically to fireworks.
What remains uncertain
- AQS qualifiers are submitting-agency causal flags and do not by themselves establish EPA concurrence.
- The evidence resolves the broad cause but does not require a named fire, facility, or incident.
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.