Other Possible
Daily PM2.5 peaked at 53.4 µg/m³ near Baton Rouge across 1 covered metro home to 882,652 people. 1 metro 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 ≈ 1.9 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 1.7 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
A large Baton Rouge structural fire produced a black smoke plume on the afternoon before the October 7 daily record. The occurrence is real and local, but no source connects it to the regulatory monitor, so it remains possible.
Possible This is a transparent hypothesis supported by limited evidence or an explicit inference, not a definitive attribution.
The Advocate (republished by MEC&F Expert Engineers) · Oct 7, 2016 hypothesis
Contemporaneous reporting documents a large October 6 Baton Rouge apartment fire that destroyed two buildings and sent a large black smoke plume over the local area.
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
The catalog has a grouping hypothesis, but no retained source directly establishes the proposed cause.
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
EPA monitors recorded the event across 1 metro. The peak daily concentration is roughly 2.4 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 “Other” explanation; it does not assign the cause by itself.
Baton Rouge, LA
Monitor comparison window 2016-10-04 to 2016-10-10 · PM2.5 target: Capitol
109% above nearby days
19% lower than surrounding days
204% higher than surrounding days
109% higher than surrounding days
204% higher than surrounding days
About the same as surrounding days
23% higher than surrounding days
13% lower than surrounding days
7% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
19% lower 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.
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Baton Rouge, LA | 53.4 µg/m³ | 2.4 | Oct 7, 2016 | #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.
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.
NOAA Satellite Services Division
NOAA reported no significant detached smoke or blowing dust in satellite imagery through 0000Z October 7.
Context for the event; this item does not establish the attributed cause by itself.
HMS text focuses on significant or detached plumes; a local attached structural-fire plume may not appear.
The Advocate (republished by MEC&F Expert Engineers)
Contemporaneous reporting documents a large October 6 Baton Rouge apartment fire that destroyed two buildings and sent a large black smoke plume over the local area.
This source supports a possible mechanism or occurrence; it does not establish the cause by itself.
The report does not measure ambient PM2.5 or connect the plume to the October 7 monitor-day value.
Possible This is a transparent hypothesis supported by limited evidence or an explicit inference, not a definitive attribution.
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.