Industrial
September 2002 Texas industrial-emissions transport episode
Daily PM2.5 peaked at 57.5 µg/m³ near Houston across 4 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 ≈ 5.9 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 126 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 industrial emissions as the broad root cause and supports grouping the contemporaneous affected events into one time-bounded episode. Qualified frozen evidence supports industrial emissions as the broad root cause and supports grouping the contemporaneous affected events into one time-bounded episode. Qualified frozen evidence supports industrial emissions as the broad root cause and supports grouping the contemporaneous affected events into one time-bounded episode.
Sequence: Houston (Sep 12) → Dallas (Sep 12) → Austin (Sep 12) → San Antonio (Sep 12)
Affected metros
| Metro | Peak PM2.5 | Cigarettes, whole event | Peak day | All-time standing |
|---|---|---|---|---|
| Houston-The Woodlands-Sugar Land, TX | 57.5 µg/m³ | 9.6 | Sep 13, 2002 | #5 of its top days |
| Dallas-Fort Worth-Arlington, TX | 53.1 µg/m³ | 6.6 | Sep 14, 2002 | #6 of its top days |
| Austin-Round Rock, TX | 53 µg/m³ | 6.9 | Sep 13, 2002 | #3 of its top days |
| San Antonio-New Braunfels, TX | 48 µg/m³ | 5.7 | Sep 14, 2002 | #6 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
Agency and publisher pages 2
- Identification of source regions affecting south Texas during the September 2002 haze event Trajectory and potential-source analysis identifies long-range transport from the eastern United States and possible contributing emission regions including industrialized Texas and Louisiana, the Mississippi Valley, Tennessee, and lower Ohio River Valley during the South Texas September 11–14 haze event with elevated PM2.5.
- A New IDEA in Air Quality Monitoring NASA describes a September 2002 haze blanket formed by humid, hot, stagnant air and industrial emissions in the upper Midwest, then moved around the eastern United States and generated air-quality alerts as far away as Texas.
What remains uncertain
- The evidence supports regional influence or transport but does not quantify the contribution to observed PM2.5.
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.