County · TRI 2024

Honolulu County, Hawaii Pollution

10 top TRI facilities tracked here. PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) held roughly steady year over year (+2%). PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations are roughly unchanged from 2010.

FIPS 15003 · population 1,010,100

PM2.5 ANNUAL MEAN (NAAQS 9 ΜG/M³ (ANNUAL)) · 20102024
Bar chart of annual values from 2010 to 2024, in µg/m³. Most recent year (2024): 4 µg/m³.6 µg/m³'10'12'14'16'18'20'22'244 µg/m³
Top facilities mapped

Where Chemicals Are Released In Honolulu County

Each red dot is one of the top TRI facilities. Size reflects 2024 total releases. County boundary outlined in blue.

STYLE10 TRI facilities · Honolulu County
Pollutant pathways

Honolulu County Pollutant Multi-Year Trends

CRITERIA AIRSINCE 2010

PM2.5 annual mean (NAAQS 9 µg/m³ (annual))Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.

4.07 µg/m³ · +2% YoY · -5% since 2010

PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations are roughly unchanged from 2010.

CRITERIA AIRSINCE 2010

PM2.5 24-hour 98th percentile (NAAQS 35 µg/m³ (24-hour))Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.

7.83 µg/m³ · -7% YoY · -26% since 2010

PM2.5 24-hour 98th percentile (NAAQS 35 µg/m³ (24-hour)) concentrations have fallen 26% since 2010.

CRITERIA AIRSINCE 2010

Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour))Health riskGround-level ozone (smog) forms when vehicle and industrial emissions react in sunlight. Inflames the airways, triggers asthma attacks, and worsens heart and lung disease.

0.044 ppm · 0% YoY · +1% since 2010

Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour)) concentrations are roughly unchanged from 2010.

CRITERIA AIRSINCE 2010

NO₂ annual mean (NAAQS 53 ppb (annual))Health riskA tailpipe and combustion gas. Concentrates near busy roads and industrial sites; raises risk of airway inflammation, asthma, and lower respiratory infections in children.

2.6 ppb · -21% YoY · -37% since 2010

NO₂ annual mean (NAAQS 53 ppb (annual)) concentrations have fallen 37% since 2010.

HAZARDOUS AIR2020 VINTAGE

Lifetime cancer risk all pollutants (100 in a million (EPA elevated threshold))Health riskEPA-modeled added cancer cases per million residents from a lifetime of breathing local air toxics. EPA flags 100-in-a-million as elevated.

16.9 per million · 2020 vintage

Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.

HAZARDOUS AIR2020 VINTAGE

Formaldehyde ambient mean (0.077 µg/m³ (1-in-a-million URE))Health riskAn air toxic emitted by refineries, wood products, and combustion. EPA classifies it as a known human carcinogen — long-term inhalation raises cancer risk.

0.78 µg/m³ · 2020 vintage

Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.

HAZARDOUS AIR2020 VINTAGE

Benzene ambient mean (0.13 µg/m³ (1-in-a-million URE))Health riskAn air toxic from gasoline, refineries, and tobacco smoke. A known human carcinogen — chronic exposure is linked to leukemia and other blood cancers.

0.19 µg/m³ · 2020 vintage

Single-vintage exposure modeling — EPA cadence is multi-year, so no trend line yet.

TRI AIRSINCE 2010

TRI air releases (5.1 fugitive + 5.2 stack)Health riskToxic chemicals reported by industrial facilities as released into the air — fugitive leaks plus smokestack emissions. Higher pounds means more inhaled exposure for nearby residents.

1.2M lb · -7% YoY · -19% since 2010

TRI air releases (5.1 fugitive + 5.2 stack) concentrations have fallen 19% since 2010.

TRI WATERSINCE 2010

TRI water releases (5.3)Health riskToxic chemicals reported by industrial facilities as discharged to surface waters (rivers, lakes, the ocean). Affects fishing, recreation, and downstream drinking-water intakes.

456k lb · -11% YoY · +1% since 2010

TRI water releases (5.3) concentrations are roughly unchanged from 2010.

TRI LANDSINCE 2010

TRI land + off-site releasesHealth riskToxic chemicals released to land on-site or transferred off-site for disposal — landfills, deep-well injection, and similar. Risks groundwater contamination over time.

113k lb · -24% YoY · -46% since 2010

TRI land + off-site releases concentrations have fallen 46% since 2010.

GHGSINCE 2010

Greenhouse gases (GHGRP large emitters, through 2023)Health riskGreenhouse gases reported by large industrial emitters under EPA's GHGRP, in metric tons of CO₂ equivalent. Drives climate warming and the heat-related health effects that follow.

17.7M metric tons CO₂e · -0% YoY · +121% since 2010

Greenhouse gases (GHGRP large emitters, through 2023) concentrations have more than doubled since 2010.

Top facilities · 2024

Where The Chemical Releases Are Concentrated

FacilityCityTop chemicalTotal releasesYoY
Hawaiian Electric CO INC Kahe Generating StationHawaiian Electric Industries INCKapoleiSulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)Health riskAcid mists are an IARC Group 1 carcinogen via inhalation (laryngeal cancer) and corrosive on contact. (IARC)691k lb-0%
Joint Base Pearl Harbor-Hickam HawaiiUS Department Of DefenseJbphhNitrate compounds (water dissociable; reportable only when in aqueous solution)Health riskDrinking-water nitrate causes methemoglobinemia ('blue-baby syndrome') in infants; EPA MCL is 10 mg/L as N. (EPA)390k lb-5%
Hawaiian Electric CO INC Waiau Generating StationHawaiian Electric Industries INCPearl CitySulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)Health riskAcid mists are an IARC Group 1 carcinogen via inhalation (laryngeal cancer) and corrosive on contact. (IARC)232k lb-29%
Par Hawaii Refining LLCPar Pacific Holdings INCKapolein-HexaneHealth riskPeripheral neurotoxin. Chronic exposure causes numbness and paralysis in the extremities. (ATSDR)165k lb+1%
US Marine Corps Base Hawaii Kaneohe BayUS Department Of DefenseMcbh Kaneohe BayNitrate compounds (water dissociable; reportable only when in aqueous solution)Health riskDrinking-water nitrate causes methemoglobinemia ('blue-baby syndrome') in infants; EPA MCL is 10 mg/L as N. (EPA)111k lb-20%
Ball Metal Beverage Container CorpBall CORPKapoleiCertain glycol ethersHealth riskReproductive toxicants; some cause testicular damage and developmental harm. (EPA)54k lb+36%
U.S. Army Schofield Barracks - Range FacilityUS Department Of DefenseSchofield BarracksCopperHealth riskInhaled copper fumes cause metal-fume fever; chronic ingestion above EPA's 1.3 mg/L action level damages the liver. (EPA)34k lb-60%
US Marine Corps Base Hawaii Puuloa Training FacilityUS Department Of DefenseEwa BeachLeadHealth riskNeurotoxin. Even low childhood exposure impairs cognitive development; chronic adult exposure damages kidneys and the cardiovascular system. (EPA, ATSDR)26k lb+31%
Hffc Sand Island Fuel TerminalHonoluluXylene (mixed isomers)Health riskEye, skin, and respiratory irritant; central-nervous-system effects from chronic exposure. (EPA)6k lb+4%
Hawaiian Electric Campbell Industrial Park Generating Sta.Hawaiian Electric Industries INCKapoleiPolycyclic aromatic compoundsHealth riskPAH class includes IARC Group 1 carcinogens (e.g., benzo[a]pyrene); long-term exposure raises cancer risk. (IARC, EPA)4k lb+2544%
Superfund / NPL sites

Federal Cleanup Sites In Honolulu County

Sites on EPA's Superfund National Priorities List, plus deleted sites whose cleanup objectives EPA has finalized. Federal-facility sites (defense, DOE, etc.) are flagged separately. Each link routes to a per-site page.

Methodology →

SiteCityStatusFederal facilityPrimary contaminant
Del Monte Corp. (Oahu Plantation)KuniaNPL FINALNo1,2,3-Trichloropropane
Naval Computer And Telecommunications Area Master Station Eastern PacificWahiawaNPL FINALFEDERALPolychlorinated Biphenyls (Pcbs)Health riskPCBs. IARC Group 1 carcinogen; immune, reproductive, and neurological effects; bioaccumulate in fish and breast milk. Banned in 1979; persist as legacy contamination. (IARC, EPA)
Pearl Harbor Naval ComplexPearl HarborNPL FINALFEDERALArsenicHealth riskIARC Group 1 carcinogen via inhalation and ingestion. EPA MCL 10 µg/L; chronic exposure causes skin, lung, bladder cancer and cardiovascular disease. (IARC, EPA, ATSDR)
Schofield Barracks (Usarmy)Wheeler AFBDELETEDFEDERALCarbon TetrachlorideHealth riskIARC Group 2B possible carcinogen; liver toxic. EPA MCL 5 µg/L. Banned for most uses since 1986. (IARC, EPA)
Equity context · ACS 2018-2022 · USEPA-clone EJ disparity

Who Lives In Honolulu County

All block groups in Honolulu County County, HI: 1,010,100 residents. County disparity score for nitrogen dioxide (no₂) sits below the reference (64). Why we surface this →

POPULATION SHARE
8.8%

Low-income

POPULATION SHARE
82.6%

People of color

POPULATION SHARE
5.8%

Under age 5

POPULATION SHARE
18.6%

Over age 64

NATIONAL PERCENTILE · vs all US block groups (population-weighted; ranked against the national EJScreen indicator distribution)

  • Nitrogen dioxide (NO₂)Health riskA tailpipe and combustion gas. Concentrates near busy roads and industrial sites; raises risk of airway inflammation, asthma, and lower respiratory infections in children.33below the national median
  • Diesel particulateHealth riskSoot from diesel engines (trucks, trains, ports, construction). EPA classifies it as a likely human carcinogen and a major driver of childhood asthma near freight corridors.43near the national median
  • Toxic releases (RSEI)Health riskEPA's Risk-Screening Environmental Indicators score — weights TRI chemical releases by toxicity, where they go, and how many people are nearby. Higher means greater modeled cancer and chronic-health risk.46near the national median
  • Traffic proximityHealth riskPopulation-weighted distance to high-volume roads. Living close to heavy traffic raises exposure to PM2.5, NO₂, and diesel exhaust — and the cardiovascular and asthma risks that follow.82in the highest 20% nationally
  • Lead-paint risk (pre-1960 housing)Health riskShare of housing built before 1960, when lead-based paint was common. Dust from deteriorating paint is the leading cause of childhood lead poisoning, which permanently impairs cognitive development.53near the national median
  • Superfund site proximityHealth riskPopulation-weighted distance to NPL Superfund sites — the most contaminated waste sites in the country. Nearby groundwater, soil, and air can carry industrial solvents, metals, and other long-lived contaminants.92in the highest 10% nationally
  • RMP-facility proximityHealth riskDistance to facilities holding chemicals at quantities large enough to require an EPA Risk Management Plan (refineries, fertilizer plants, etc.). These pose acute exposure risk during accidental releases.28below the national median
  • Hazardous-waste site proximityHealth riskDistance to RCRA hazardous-waste handlers (treatment, storage, disposal facilities). Indicates potential exposure to industrial chemicals in air, soil, and groundwater.53near the national median
  • Underground storage tanksHealth riskDensity of underground tanks (gasoline, heating oil, industrial fluids). Leaking tanks are a leading source of benzene and other volatile organic compounds in groundwater drinking-water supplies.78above the national median
  • NPDES wastewater proximityHealth riskDistance to permitted industrial wastewater dischargers. Closer proximity raises exposure to pollutants released into surface waters used for fishing, recreation, and downstream drinking-water intakes.100in the highest 5% nationally
  • Drinking-water non-complianceHealth riskEPA score for public water systems with health-based Safe Drinking Water Act violations. Higher means more residents on systems that recently exceeded safe limits for contaminants like lead, arsenic, or nitrate.76above the national median
EJ disparity scores · population-weighted across county block groups (100 = national reference; higher = greater disparate burden)
IndicatorDisparity scoreReading
Nitrogen dioxide (NO₂)64below the reference
Diesel particulate63below the reference
Toxic releases (RSEI)72below the reference
Traffic proximity133moderately above the reference
Lead-paint risk (pre-1960 housing)66below the reference
Superfund site proximity115moderately above the reference
RMP-facility proximity14well below the reference
Hazardous-waste site proximity81below the reference
Underground storage tanks100near the reference
NPDES wastewater proximity133moderately above the reference
Drinking-water non-compliance1well below the reference

Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).

Health context

Co-Located Health Indicators

Modeled adult-prevalence estimates published by CDC PLACES, paired with this county's pollution and demographic context. Comparisons are ecological, not causal — pollution and disease prevalence covary at the area level, but the data does not attribute any individual's diagnosis to local exposure. How this section works →

Adult asthma (current)

BRFSS 2023
9.5%
-4% vs Hawaii mean-3% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

COPD prevalence

BRFSS 2023
4.7%
-7% vs Hawaii mean-26% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

Coronary heart disease

BRFSS 2023
5.8%
-4% vs Hawaii mean-13% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

Diabetes (diagnosed)

BRFSS 2023
12.4%
+3% vs Hawaii mean+0% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

Frequent mental distress

BRFSS 2023
14.2%
-4% vs Hawaii mean-9% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

PLACES uses BRFSS-modeled small-area estimates, not individual records. Crude prevalence shown above is the local rate as published; comparators are age-adjusted vs the Hawaii mean and the US mean — both population-weighted across counties — so geographies with different age structures stay apples-to-apples. Sources: CDC PLACES · 2025 release · BRFSS 2022-2023.

Sources.

All sources are federal public-domain datasets under 17 USC §105. We aggregate but do not relabel; the underlying observations remain attributable to EPA.