2004-12-31 fireworks episode affecting Urban Honolulu, HI
December 31, 2004 to January 1, 2005
Daily PM2.5 peaked at 102.8 µg/m³ near Urban Honolulu across
1 covered metro home to 998,747 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 ≈ 6.7 cigarettes.
Across everyone living in the affected metros, that is the collective equivalent of
≈ 6.7 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
The basis for “Fireworks”
Qualified frozen evidence supports fireworks as the broad root cause.
EPA monitor flagEPA 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 · Jan 1, 2005official
EPA AQS carries an agency-submitted request-exclusion qualifier (RK, Infrequent Large Gatherings.) on 2 PM2.5 samples in the candidate CBSA on 2005-01-01, identifying infrequent large gatherings as affecting the samples. 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 · Dec 31, 2004official
EPA AQS carries an agency-submitted request-exclusion qualifier (RK, Infrequent Large Gatherings.) on 1 PM2.5 sample in the candidate CBSA on 2004-12-31, identifying infrequent large gatherings as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
The study measured the 2004–2005 New Year fireworks celebration in Pearl City, within metropolitan Honolulu, and evaluated ambient-air metals and particulate pollution attributable to fireworks.
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.
EPA AQS carries an agency-submitted request-exclusion qualifier (RK, Infrequent Large Gatherings.) on 2 PM2.5 samples in the candidate CBSA on 2005-01-01, identifying infrequent large gatherings as affecting the samples. A request-exclusion…
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
102.8 µg/m³ near Urban Honolulu
EPA monitors recorded the event across 1 metro.
The peak daily concentration is roughly 4.7 cigarette-equivalents at the outdoor daily rate.
Before, during, and after the episode: nearby pollutant monitors and surface-weather
stations show what changed. This context tests the “Fireworks” explanation; it does
not assign the cause by itself.
Observed context · not attribution
Urban Honolulu, HI
Monitor comparison window 2004-12-28 to 2005-01-04 · PM2.5 target: Pearl City
6 pollutant signals
Fine-particle pulse55.6 µg/m³
1468% above nearby days
PM1063.5 µg/m³
316% higher than surrounding days
Pollution fingerprint
Metro-wide median of reporting monitors
PM2.555.6 µg/m³
1468% higher than surrounding days
Before3.05 µg/m³ Event55.6 µg/m³ After3.45 µg/m³
PM1063.5 µg/m³
316% higher than surrounding days
Before11 µg/m³ Event63.5 µg/m³ After16 µg/m³
Carbon monoxide0.700 ppm
6% lower than surrounding days
Before0.721 ppm Event0.700 ppm After0.846 ppm
Nitrogen dioxide3.96 ppb
16% lower than surrounding days
Before5.19 ppb Event3.96 ppb After5.18 ppb
Sulfur dioxide0.693 ppb
About the same as surrounding days
Before0.363 ppb Event0.693 ppb After0.783 ppb
Ozone0.016 ppm
28% lower than surrounding days
Before0.021 ppm Event0.016 ppm After0.024 ppm
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.
—
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.
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.
"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.
U.S. EPA Air Quality System and the submitting air monitoring agency · Jan 1, 2005officialgovernment
EPA AQS carries an agency-submitted request-exclusion qualifier (RK, Infrequent Large Gatherings.) on 2 PM2.5 samples in the candidate CBSA on 2005-01-01, identifying infrequent large gatherings as affecting the samples. 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 · Dec 31, 2004officialgovernment
EPA AQS carries an agency-submitted request-exclusion qualifier (RK, Infrequent Large Gatherings.) on 1 PM2.5 sample in the candidate CBSA on 2004-12-31, identifying infrequent large gatherings as affecting the sample. A request-exclusion qualifier is an official submitting-agency causal claim, but this endpoint does not establish EPA concurrence.
Environmental Health Perspectives · Jennifer A. Licudine et al.official
The study measured the 2004–2005 New Year fireworks celebration in Pearl City, within metropolitan Honolulu, and evaluated ambient-air metals and particulate pollution attributable to fireworks.
The Honolulu Advertiser · Mike Leidemann · Dec 26, 2004corroborates
Contemporaneous reporting documented Honolulu officials' concern over New Year's Eve fireworks pollution, described state Health Department sampling of prior celebration smoke, and reported a sharp increase in permits ahead of the 2004–2005 celebration.
Status and provenance
EPA monitor flagEPA attached an exceptional-event qualifier to the affected samples. The agency flagged the measurement itself; no separate agency record describes the event.
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.