Dust
June 2022 Gulf and southern Plains Saharan-dust episode
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.
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
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. 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. 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 oc
Sequence: Baton Rouge (Jun 13) → Jackson (Jun 13) → San Antonio (Jun 16) → McAllen (Jun 16) → Austin (Jun 16) → Oklahoma City (Jun 17)
Affected metros
| 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.
The evidence
EPA AQS monitor qualifier 12
- 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.
NWS Air Quality Alert 1
- Air Quality Alert AQALIX 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.
Agency and publisher pages 3
- 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.
- June 13, 2022 forecast TCEQ forecast PM2.5 and PM10 concerns in Austin and San Antonio and identified transported African dust among the regional particulate contributors under consideration.
What remains uncertain
- Agency-submitted AQS qualifiers support attribution but do not by themselves establish EPA concurrence.
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.