Dust Agency determination
Daily PM2.5 peaked at 51.8 µg/m³ near Baton Rouge across 6 covered metros home to 9.2 million 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 ≈ 2.5 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
Event-specific official evidence identifies African dust, while supplied scientific context reconstructs one June 12-17 trans-Atlantic Saharan-dust outbreak reaching the Gulf region. The directly attributed focal events are grouped as manifestations of that occurrence. The directly attributed focal events are grouped as manifestations of that oc
Agency determination A government body issued a record naming this cause for this event: an NWS air-quality alert, a NOAA Storm Events record, or a state or local official archive.
U.S. EPA Air Quality System and the submitting air monitoring agency · Jun 15, 2022 official
EPA AQS carries an agency-submitted request-exclusion qualifier (RA, African Dust.) on 1 PM2.5 sample in the candidate CBSA on 2022-06-15, 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 · Jun 15, 2022 official
EPA AQS carries an agency-submitted informational qualifier (IA, African Dust.) on 49 PM2.5 samples in the candidate CBSA on 2022-06-15, identifying windblown or transported dust 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 · Jun 14, 2022 official
EPA AQS carries an agency-submitted informational qualifier (IA, African Dust.) on 49 PM2.5 samples in the candidate CBSA on 2022-06-14, identifying windblown or transported dust 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: Baton Rouge (Jun 13) → San Antonio (Jun 13) → Austin (Jun 13) → Jackson (Jun 13) → McAllen (Jun 16) → Oklahoma City (Jun 17)
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 2022-06-15, identifying windblown or transported dust as affecting the sample. A request-exclusion qualifier is an…
View supporting source ↗Air-mass movement
The state demonstration includes June 13 PM2.5 trajectory analysis at the Austin Webberville monitor and analyses of transported material from western Africa.
View transport source ↗Local response
EPA monitors recorded the event across 6 metros. 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 “Dust” explanation; it does not assign the cause by itself.
Baton Rouge, LA
Monitor comparison window 2022-06-10 to 2022-06-18 · PM2.5 target: Capitol
98% above nearby days
About the same as surrounding days
100% higher than surrounding days
98% higher than surrounding days
100% higher than surrounding days
About the same as surrounding days
19% lower than surrounding days
5% lower than surrounding days
About the same as surrounding days
8% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
Jackson, MS
Monitor comparison window 2022-06-10 to 2022-06-18 · PM2.5 target: Jackson NCORE
128% above nearby days
5% higher than surrounding days
219% higher than surrounding days
128% higher than surrounding days
219% higher than surrounding days
9% lower than surrounding days
24% higher than surrounding days
29% lower than surrounding days
About the same as surrounding days
About the same as surrounding days
5% higher than surrounding days
Austin-Round Rock, TX
Monitor comparison window 2022-06-13 to 2022-06-19 · PM2.5 target: Austin North Interstate 35
45% above nearby days
No adjacent-day comparison
45% higher than surrounding days
No adjacent-day comparison
About the same as surrounding days
28% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
San Antonio-New Braunfels, TX
Monitor comparison window 2022-06-13 to 2022-06-19 · PM2.5 target: Old Hwy 90
66% above nearby days
About the same as surrounding days
No adjacent-day comparison
66% higher than surrounding days
No adjacent-day comparison
5% lower than surrounding days
About the same as surrounding days
345% higher than surrounding days
About the same as surrounding days
About the same as surrounding days
About the same as surrounding days
McAllen-Edinburg-Mission, TX
Monitor comparison window 2022-06-13 to 2022-06-19 · PM2.5 target: Edinburg East Freddy Gonzalez Drive
71% above nearby days
71% higher than surrounding days
About the same as surrounding days
Oklahoma City, OK
Monitor comparison window 2022-06-14 to 2022-06-20 · PM2.5 target: MOORE
70% above nearby days
40% lower than surrounding days
114% higher than surrounding days
70% higher than surrounding days
114% higher than surrounding days
11% higher than surrounding days
71% higher than surrounding days
Adjacent observations available
About the same as surrounding days
9% lower than surrounding days
About the same as surrounding days
40% 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.
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 |
|---|---|---|---|---|
| Baton Rouge, LA | 51.8 µg/m³ | 6.6 | Jun 13, 2022 | #4 of its top days |
| San Antonio-New Braunfels, TX | 41.3 µg/m³ | 3.5 | Jun 16, 2022 | #14 of its top days |
| McAllen-Edinburg-Mission, TX | 40.5 µg/m³ | 3.7 | Jun 16, 2022 | #22 of its top days |
| Austin-Round Rock, TX | 37.4 µg/m³ | 3.2 | Jun 16, 2022 | #14 of its top days |
| Jackson, MS | 37.2 µg/m³ | 1.7 | Jun 13, 2022 | #14 of its top days |
| Oklahoma City, OK | 35.6 µg/m³ | 1.6 | Jun 17, 2022 | #17 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 2022-06-15, 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 IA — African Dust.
EPA AQS carries an agency-submitted informational qualifier (IA, African Dust.) on 49 PM2.5 samples in the candidate CBSA on 2022-06-15, identifying windblown or transported dust 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 IA — African Dust.
EPA AQS carries an agency-submitted informational qualifier (IA, African Dust.) on 49 PM2.5 samples in the candidate CBSA on 2022-06-14, identifying windblown or transported dust 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 IA — African Dust.
EPA AQS carries an agency-submitted informational qualifier (IA, African Dust.) on 50 PM2.5 samples in the candidate CBSA on 2022-06-13, identifying windblown or transported dust 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 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 2022-06-14, 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 2022-06-13, 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 24 PM2.5 samples in the candidate CBSA on 2022-06-13, identifying windblown or transported dust 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 RA — African Dust.
EPA AQS carries an agency-submitted request-exclusion qualifier (RA, African Dust.) on 24 PM2.5 samples in the candidate CBSA on 2022-06-13, identifying windblown or transported dust 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 RA — African Dust.
EPA AQS carries an agency-submitted request-exclusion qualifier (RA, African Dust.) on 24 PM2.5 samples in the candidate CBSA on 2022-06-16, identifying windblown or transported dust 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 RA — African Dust.
EPA AQS carries an agency-submitted request-exclusion qualifier (RA, African Dust.) on 24 PM2.5 samples in the candidate CBSA on 2022-06-16, identifying windblown or transported dust 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 RA — African Dust.
EPA AQS carries an agency-submitted request-exclusion qualifier (RA, African Dust.) on 24 PM2.5 samples in the candidate CBSA on 2022-06-16, identifying windblown or transported dust 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 RA — African Dust.
EPA AQS carries an agency-submitted request-exclusion qualifier (RA, African Dust.) on 96 PM2.5 samples in the candidate CBSA on 2022-06-17, identifying windblown or transported dust as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
An archived NWS Air Quality Alert for Baton Rouge, LA, issued 2022-06-13T14:47Z, explicitly identifies windblown or transported dust. IEM is the archive, not the official system of record.
Exceptional Events Demonstration for 2022 PM2.5
The state demonstration includes June 13 PM2.5 trajectory analysis at the Austin Webberville monitor and analyses of transported material from western Africa.
Monday PM Forecast: high heat, low air quality
Contemporaneous Baton Rouge reporting says southwesterly winds were transporting Saharan dust across Louisiana and that high pressure was limiting atmospheric mixing.
TCEQ forecast PM2.5 and PM10 concerns in Austin and San Antonio and identified transported African dust among the regional particulate contributors under consideration.
Agency determination A government body issued a record naming this cause for this event: an NWS air-quality alert, a NOAA Storm Events record, or a state or local official archive.
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.