Pollution Analyst
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State · TRI 2024

Mississippi Pollution

264 TRI facilities, 990 public water systems, and 14 Superfund / NPL sites across 67 counties. Statewide TRI releases rose modestly year over year (+8%). Toxic releases concentrations have fallen 18% since 2010.

FIPS 28 · population 2,961,279 · 82 counties total

Top counties Top facilitiesPathwaysEquity context
PM2.5 ANNUAL MEAN (NAAQS 9 ΜG/M³ (ANNUAL)) · 2010–2024
Bar chart of annual values from 2010 to 2024, in µg/m³. Most recent year (2024): 8 µg/m³.14 µg/m³'10'12'16'18'20'22'248 µg/m³
Anomaly engine

Notable Signals At The State Level

LONG-ARC REGRESSION · LONG-ARC SHIFT

TRI water releases

TRI water releases at Mississippi have more than doubled since 2010 (through 2024).

Where the burden sits

County-Level TRI Choropleth

A color-shaded map of pollution data. Darker counties report more pounds of toxic chemicals released to the EPA's Toxics Release Inventory (TRI).

Shaded by total reported releases for 2024. Counties without a published page render as “no TRI data”. Red dots mark this state's top emitters.

STYLE
TRI total releases (lbs/yr)
LOW → HIGH
Statewide pollutant pathways

Mississippi 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.

8.36 µg/m³ · -16% YoY · -42% since 2010

PM2.5 annual mean (NAAQS 9 µg/m³ (annual)) concentrations have fallen 42% 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.

18.73 µg/m³ · -19% YoY · -42% since 2010

PM2.5 24-hour 98th percentile (NAAQS 35 µg/m³ (24-hour)) concentrations have fallen 42% 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.

0.063 ppm · -4% YoY · -26% since 2010

Ozone 8-hour 4th-highest daily max (NAAQS 0.070 ppm (8-hour)) concentrations have fallen 26% 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.

3.6 ppb · -1% YoY · -45% since 2010

NO₂ annual mean (NAAQS 53 ppb (annual)) concentrations have fallen 45% 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.

31.5 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.

1.87 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.

0.09 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.

14.1M lb · +6% YoY · -29% since 2010

TRI air releases (5.1 fugitive + 5.2 stack) concentrations have fallen 29% 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.

10.3M lb · +1% YoY · +105% since 2010

TRI water releases (5.3) concentrations have more than doubled since 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.

25.8M lb · +13% YoY · -29% since 2010

TRI land + off-site releases concentrations have fallen 29% 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.

110M metric tons CO₂e · -1% YoY · +64% since 2010

Greenhouse gases (GHGRP large emitters, through 2023) concentrations are up 64% since 2010.

Top counties · TRI 2024

Mississippi Counties With Most Chemical Releases

Methodology →

CountyPopulationFacilitiesTotal releasesYoYTop chemical
Harrison CountyFIPS 28047208,7481111.0M lb+31%Manganese compoundsHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)
Monroe CountyFIPS 2809534,168710.2M lb+3%Manganese compoundsHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)
Warren CountyFIPS 2814944,34143.2M lb+1%MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA)
Perry CountyFIPS 2811111,51113.0M lb+4%MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA)
Jackson CountyFIPS 28059143,721122.7M lb-4%Nitrate 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)
Lowndes CountyFIPS 2808758,547122.2M lb-6%MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA)
Leake CountyFIPS 2807921,33511.9M lb+4%Nitrate 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)
Lawrence CountyFIPS 2807711,93321.9M lb+8%MethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA)
Choctaw CountyFIPS 280198,20831.6M lb+13%Manganese And Manganese CompoundsHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)
Yazoo CountyFIPS 2816327,46741.4M lb+10%AmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA)
Top facilities · TRI 2024

The Largest Individual Emitters In Mississippi

Methodology →

FacilityCityTop chemicalTotal releasesYoY
Chemours Delisle PlantThe Chemours CoPass ChristianManganese compoundsHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)10.9M lb+32%
Tronox LLCTronox LTDHamiltonManganese compoundsHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)10.1M lb+3%
Georgia Pacific Leaf River Cellulose LLCKoch INCNew AugustaMethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA)3.0M lb+4%
International Paper-Vicksburg MillInternational Paper CoRedwoodMethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA)2.1M lb-1%
Chevron Products CO Pascagoula RefineryChevron CORPPascagoulaNitrate 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)2.0M lb-9%
Tyson Farms INC. - Carthage Ms Processing PlantTyson Foods INCCarthageNitrate 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)1.9M lb+4%
Georgia-Pacific Monticello LLCKoch INCMonticelloMethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA)1.9M lb+8%
Columbus Cellulose FibersInternational Paper CoColumbusMethanolHealth riskAcutely toxic if ingested or inhaled. Metabolizes to formaldehyde and formic acid, causing blindness and metabolic acidosis. (EPA)1.8M lb-10%
Choctaw Generation LP L.L.L.P.Choctaw Generation LP LllpAckermanManganese And Manganese CompoundsHealth riskExcess inhalation can cause manganism, a Parkinson-like neurological disorder. (ATSDR)1.5M lb+11%
Cf Industries Nitrogen LLC - Yazoo City Mississippi PlantCf Industries Holdings INCYazoo CityAmmoniaHealth riskSevere respiratory and eye irritant; high concentrations cause chemical burns to lung tissue. (EPA)1.3M lb+12%
Water utilities to watch

Largest Water Systems With Unresolved Health-Based Violations

Sorted to surface utilities serving the most people that still have an active health-based SDWIS violation on the record. Systems in compliance with no unresolved issues fall to the bottom of the ranking.

Methodology →

Water systemPWSIDPopulation servedHealth-based · 5yrStatus
City Of Jackson MunicipalMS0250008189,67389UNRESOLVED
City Of Brandon MunicipalMS061000331,8522UNRESOLVED
City Of Jackson-Maddox Rd. MunicipalMS025001228,09821UNRESOLVED
City Of Clinton MunicipalMS025000325,0002UNRESOLVED
City Of Canton MunicipalMS045000616,7852UNRESOLVED
City Of Cleveland MunicipalMS006000616,3923UNRESOLVED
Clarksdale Public Utilities MunicipalMS014000214,90322UNRESOLVED
City Of Hernando MunicipalMS017000914,4573UNRESOLVED
City Of Moss Point MunicipalMS030000812,5244UNRESOLVED
City Of Brookhaven MunicipalMS043000212,5132UNRESOLVED
Superfund / NPL sites

Federal Cleanup Sites In Mississippi

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
American Creosote Works Inc (Louisville)LouisvilleNPL FINALNo1,2-Dihydroacenaphthylene
Chemfax, Inc.GulfportNPL FINALNo2-Hexanone
Hercules IncHattiesburgNPL FINALNo—
Kerr-Mcgee Chemical Corp - ColumbusColumbusNPL FINALNo9H-Carbazole
Mississippi Phosphates CorporationPascagoulaNPL FINALNo—
Picayune Wood Treating SitePicayuneNPL FINALNoPentachlorophenolHealth riskIARC Group 1 carcinogen; wood preservative; persistent in soil and groundwater. (IARC, EPA)
Rockwell International Wheel & TrimGrenadaNPL FINALNo—
Sonford ProductsFlowoodNPL FINALNoChlorinated Dioxins And Furans
Southeastern Wood PreservingCantonNPL FINALNo2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Tcdd) Toxicity Equivalents (Teq)
Davis Timber CompanyHattiesburgDELETEDNo2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Tcdd) Toxicity Equivalents (Teq)

Showing the top 10 sites by status priority. 4 additional NPL-relevant sites in Mississippi have entity pages — browse them via the host-county or host-city page rollups.

Equity context · ACS 2018-2022 · USEPA-clone EJ disparity

Statewide Population Characteristics

All Mississippi block groups: 2,961,279 residents. Statewide disparity score for pm2.5 (fine particulate) sits moderately above the reference (112). Why we surface this →

State-level percentiles are aggregated from block-group EJScreen data. The EJ pattern within the state will be sharper at the county level — drill down for the meaningful spatial detail.

POPULATION SHARE
19.2%

Low-income

POPULATION SHARE
44.1%

People of color

POPULATION SHARE
6.2%

Under age 5

POPULATION SHARE
16.5%

Over age 64

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

Methodology →

  • 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.69above the national median
  • OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.13below the national median
  • 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.20below 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.19below 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.72above 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.29below the national median
  • 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.48near 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.56near 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.58near 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.32below 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.70above 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.59near 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.92in the highest 10% nationally
EJ disparity scores · population-weighted, all state block groups (100 = national reference; higher = greater disparate burden) · Methodology →
IndicatorDisparity scoreReading
PM2.5 (fine particulate)112moderately above the reference
Ozone29well below the reference
Nitrogen dioxide (NO₂)42well below the reference
Diesel particulate37well below the reference
Toxic releases (RSEI)64below the reference
Traffic proximity41well below the reference
Lead-paint risk (pre-1960 housing)62below the reference
Superfund site proximity27well below the reference
RMP-facility proximity63below the reference
Hazardous-waste site proximity40well below the reference
Underground storage tanks87below the reference
NPDES wastewater proximity54below the reference
Drinking-water non-compliance48well below the reference

Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror). EJ disparity scores via the USEPA-clone GitHub mirror after EPA deprecated the public EJScreen tool in 2025; demographics from Census ACS.

Browse

All 67 Mississippi Counties With TRI Data

Pollution trends and TRI 2024 pages for every tracked county. Alphabetical.

Sources.