Other EPA monitor flag

2005-10-29 other documented PM source or accumulation mechanism episode affecting New Orleans-Metairie, LA

October 29, 2005

Daily PM2.5 peaked at 59.2 µg/m³ near New Orleans across 1 covered metro home to 966,230 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 ≈ 2.3 cigarettes. Across everyone living in the affected metros, that is the collective equivalent of ≈ 2.2 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

The basis for “Other”

Qualified frozen evidence supports other documented PM source or accumulation mechanism as the broad root cause.

EPA monitor flag EPA attached an exceptional-event qualifier to the affected samples. The agency flagged the measurement itself; no separate agency record describes the event.

U.S. EPA Air Quality System and the submitting air monitoring agency · Oct 29, 2005 official

AQS PM2.5 qualifier RD — Cleanup After a Major Disaster.

EPA AQS carries an agency-submitted request-exclusion qualifier (RD, Cleanup After a Major Disaster.) on 7 PM2.5 samples in the candidate CBSA on 2005-10-29, identifying cleanup after a major disaster as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.

See every retained source and limitation ↓

Evidence path

From source to city

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.

Open the evidence ledger ↓

1

Source or mechanism

Other

EPA AQS carries an agency-submitted request-exclusion qualifier (RD, Cleanup After a Major Disaster.) on 7 PM2.5 samples in the candidate CBSA on 2005-10-29, identifying cleanup after a major disaster as affecting the samples. A request-exclusion…
View supporting source ↗
Documented
2

Air-mass movement

The transport path has not been reconstructed

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.

Research gap
3

Local response

59.2 µg/m³ near New Orleans

EPA monitors recorded the event across 1 metro. The peak daily concentration is roughly 2.7 cigarette-equivalents at the outdoor daily rate.
Inspect the pollutant and weather signals ↓
Documented

Event autopsy

What the instruments saw

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.

Observed context · not attribution

New Orleans-Metairie, LA

Monitor comparison window 2005-10-26 to 2005-11-01 · PM2.5 target: Bucktown - Coast Guard Station

5 pollutant signals

Fine-particle pulse 32.9 µg/m³

71% above nearby days

Air movement 2.02 kt

21% lower than surrounding days

Carbon monoxide 1.08 ppm

12% higher than surrounding days

Pollution fingerprint

Metro-wide median of reporting monitors

PM2.5 32.9 µg/m³

71% higher than surrounding days

Before18.2 µg/m³ Event32.9 µg/m³ After19.3 µg/m³

Carbon monoxide 1.08 ppm

12% higher than surrounding days

Before0.967 ppm Event1.08 ppm After1.12 ppm

Nitrogen dioxide 14.6 ppb

24% higher than surrounding days

Before10.1 ppb Event14.6 ppb After11.7 ppb

Sulfur dioxide 2.58 ppb

68% higher than surrounding days

Before1.54 ppb Event2.58 ppb After1.14 ppb

Ozone 0.031 ppm

About the same as surrounding days

Before0.034 ppm Event0.031 ppm After0.028 ppm

Atmospheric conditions

Nearby EPA weather observations

Wind 2.02 kt

21% 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.

Measured daily PM2.5 at EPA monitors, as cigarette-equivalents

EPA monitors sit in metro areas, so the colour clusters there. Land between and beyond them is unmeasured, not clean: this map shows where IAQng has readings, not the extent of the smoke.

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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.

Affected metros

Metro	Peak PM2.5	Cigarettes, whole event	Peak day	All-time standing
New Orleans-Metairie, LA	59.2 µg/m³	2.7	Oct 29, 2005	#2 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

What supports this account

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.

EPA AQS monitor qualifier 1

AQS PM2.5 qualifier RD — Cleanup After a Major Disaster.

U.S. EPA Air Quality System and the submitting air monitoring agency · Oct 29, 2005 official government

EPA AQS carries an agency-submitted request-exclusion qualifier (RD, Cleanup After a Major Disaster.) on 7 PM2.5 samples in the candidate CBSA on 2005-10-29, identifying cleanup after a major disaster as affecting the samples. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.

What remains uncertain

AQS qualifiers are submitting-agency causal flags and do not by themselves establish EPA concurrence.
The retained evidence does not map the documented mechanism to a more specific catalog cause type.

Status and provenance