Fireworks
2020-07-05 2-area fireworks episode
Daily PM2.5 peaked at 61.8 µg/m³ near Cleveland across 2 covered metros home to 3.3 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 ≈ 2.2 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
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.
Sequence: Cleveland (Jul 5) → Buffalo (Jul 5)
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Cleveland-Elyria, OH | 61.8 µg/m³ | 2.8 | Jul 5, 2020 | #9 of its top days |
| Buffalo-Cheektowaga-Niagara Falls, NY | 58.1 µg/m³ | 2.6 | Jul 5, 2020 | #3 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
News discovery (GDELT) 1
- Smoke from fireworks creates early morning haze The opened Buffalo report quotes a National Weather Service meteorologist explaining that smoke from extensive neighborhood fireworks became trapped and created early-morning haze and a burning odor. It supports fireworks for the Buffalo member but does not establish the Cleveland member or quantify PM2.5 contribution.
What remains uncertain
- The supplied evidence resolves cause but does not establish identity with another candidate episode.
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.