County · TRI 2024

Milwaukee County, Wisconsin Pollution

10 top TRI facilities tracked here. PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) fell meaningfully year over year (-30%). PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations have fallen 47% since 2010.

FIPS 55079 · population 933,063

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): 7 µg/m³.13 µg/m³'10'12'14'16'18'20'22'247 µg/m³
Top facilities mapped

Where Chemicals Are Released In Milwaukee County

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

STYLE10 TRI facilities · Milwaukee County
Pollutant pathways

Milwaukee 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.

6.94 µg/m³ · -30% YoY · -47% since 2010

PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations have fallen 47% since 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.

17.48 µg/m³ · -53% YoY · -44% since 2010

PM2.5 24-hour 98th percentile (NAAQS 35 µg/m³ (24-hour)) concentrations have fallen 44% 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.

0.066 ppm · -10% YoY · -11% since 2010

Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour)) concentrations have fallen 11% since 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.

7.8 ppb · -3% YoY · -54% since 2010

NO₂ annual mean (NAAQS 53 ppb (annual)) concentrations have more than halved 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.

28.4 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.

1.14 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.

0.20 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.

565k lb · +12% YoY · -52% since 2010

TRI air releases (5.1 fugitive + 5.2 stack) concentrations have more than halved 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.

2k lb · -17% YoY · since 2010

TRI water releases (5.3) volumes here are too small to anchor a multi-year trend; YoY movement is still shown above.

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.

1.4M lb · -10% YoY · -24% since 2010

TRI land + off-site releases concentrations have fallen 24% 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.

25.5M metric tons CO₂e · -2% YoY · +24% since 2010

Greenhouse gases (GHGRP large emitters, through 2023) concentrations are up 24% since 2010.

Top facilities · 2024

Where The Chemical Releases Are Concentrated

FacilityCityTop chemicalTotal releasesYoY
Ppg Industries Inc-Oak CreekPpg Industries INCOak CreekMethyl isobutyl ketoneHealth riskEye, skin, and respiratory irritant; central-nervous-system depressant at high exposure. (NIOSH)999k lb+69%
Oak Creek SiteWec Energy GroupOak CreekBarium compounds (except for barium sulfate (CAS No. 7727-43-7))Health riskSoluble barium compounds are toxic if ingested, affecting the heart, kidneys, and nervous system. Insoluble forms (e.g. barium sulfate) are far less toxic. (EPA)411k lb-31%
Wpc TechnologiesOak CreekNitrate 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)116k lb+7%
Seidel Tanning CorpSeidel Tanning CORPMilwaukeeChromium and Chromium Compounds(except for chromite ore mined in the Transvaal Region)Health riskHexavalent chromium (Cr-VI) is an IARC Group 1 carcinogen via inhalation, causing lung cancer; trivalent chromium is far less toxic. (IARC, EPA)89k lb+47%
Materion Advanced ChemicalsMaterion CORPMilwaukeeArsenic And Arsenic CompoundsHealth 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)51k lb+20%
Maynard Steel Casting COMilwaukeeManganese And Manganese CompoundsHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)37k lb-23%
Ge HealthcareGe Healthcare Technologies INCWest MilwaukeeNitrate 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)33k lb-28%
Acme Galvanizing INCAzz INCMilwaukeeZinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR)25k lb+1153%
Henkel US Operations CorpHenkel Of America INCOak CreekZinc compoundsHealth riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR)23k lb-91%
Hentzen Coatings,IncHentzen Coatings INCMilwaukeeZinc (fume or dust)Health riskGenerally low acute toxicity. Chronic high-dose exposure disrupts copper absorption and immune function. (ATSDR)21k lb-23%
Superfund / NPL sites

Federal Cleanup Sites In Milwaukee 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
Moss-American Co., Inc. (Kerr-Mcgee Oil Co.)MilwaukeeNPL FINALNoCarcinogenic Polycyclic Aromatic Hydrocarbons (Cpah)Health riskPAH class includes IARC Group 1 carcinogens (e.g., benzo[a]pyrene); long-term exposure raises cancer risk. (IARC, EPA)
Fadrowski Drum DisposalFranklinDELETEDNoAroclor 1254Health 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)
Equity context · ACS 2018-2022 · USEPA-clone EJ disparity

Who Lives In Milwaukee County

All block groups in Milwaukee County County, WI: 933,063 residents. County disparity score for pm2.5 (fine particulate) sits near the reference (107). Why we surface this →

POPULATION SHARE
17.8%

Low-income

POPULATION SHARE
50.7%

People of color

POPULATION SHARE
6.4%

Under age 5

POPULATION SHARE
14.1%

Over age 64

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

  • PM2.5 (fine particulate)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.62above the national median
  • OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.85in the highest 20% nationally
  • 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.84in the highest 20% nationally
  • 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.70above 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.97in the highest 5% nationally
  • 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.99in the highest 5% 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.84in the highest 20% nationally
  • 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.80above the national median
  • 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.88in the highest 20% nationally
  • 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.83in the highest 20% nationally
  • 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.88in the highest 20% nationally
  • 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.24below the national median
  • 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.89in the highest 20% nationally
EJ disparity scores · population-weighted across county block groups (100 = national reference; higher = greater disparate burden)
IndicatorDisparity scoreReading
PM2.5 (fine particulate)107near the reference
Ozone118moderately above the reference
Nitrogen dioxide (NO₂)142moderately above the reference
Diesel particulate115moderately above the reference
Toxic releases (RSEI)154well above the reference burden
Traffic proximity164well above the reference burden
Lead-paint risk (pre-1960 housing)133moderately above the reference
Superfund site proximity124moderately above the reference
RMP-facility proximity146moderately above the reference
Hazardous-waste site proximity139moderately above the reference
Underground storage tanks132moderately above the reference
NPDES wastewater proximity39well below the reference
Drinking-water non-compliance135moderately above 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
11.8%
+8% vs Wisconsin mean+18% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

COPD prevalence

BRFSS 2023
6.7%
+14% vs Wisconsin mean+15% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

Coronary heart disease

BRFSS 2023
6.2%
+8% vs Wisconsin mean+9% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

Diabetes (diagnosed)

BRFSS 2023
13.1%
+29% vs Wisconsin mean+19% vs US mean

CDC PLACES · 2025 release · BRFSS 2022-2023

Frequent mental distress

BRFSS 2023
17.0%
+4% vs Wisconsin mean+3% 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 Wisconsin 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.