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Mason County, Washington: environmental and disease records

Cancer mortality in Mason County is 169.1 deaths per 100,000 people per year against a U.S. rate of 143.2, a statistically significant excess. The strongest disease signals are Lung & bronchus deaths at 1.3 times the U.S. rate. Federal databases place 247 regulated facilities, sites and hazards inside the county, led by NPDES wastewater discharge permit (89), Rail grade crossing (82), Gas station (mapped facility) (26). 2 correctional facilities operate in the county, at least one with health-based drinking water violations on record. EPA AirToxScreen estimates a lifetime cancer risk from outdoor air toxics of 20 in a million, driven mainly by formaldehyde.

Rates are age-adjusted per 100,000 people. A cancer signal is marked significant when the lower bound of its 95 percent confidence interval is above the U.S. rate. Facility counts use active federal records located inside the county boundary. Approximate county center: 47.3451, -123.3248.

How this county ranks in Washington

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Cancer deaths and new cases versus the United States

Source: NCI and CDC State Cancer Profiles, both sexes, all ages. Sorted by the ratio of the county rate to the U.S. rate.

Cancer rates for Mason County compared with the United States
Cancer	Measure	County rate	U.S. rate	Times U.S.	95% interval	Years
Melanoma of the skin	Deaths	3.2	2	1.6x	1.9 to 5.3	2020-2024
Esophagus	New cases	6.6	4.6	1.43x	4.5 to 9.5	2019-2023
Esophagus	Deaths	4.9	3.7	1.32x	3.1 to 7.4	2020-2024
Melanoma of the skin	New cases	31.4	23.8	1.32xSignificant	26.3 to 37.3	2019-2023
Liver & bile duct	New cases	11.3	8.7	1.3x	8.5 to 14.8	2019-2023
Liver & bile duct	Deaths	8.5	6.6	1.29x	6.2 to 11.4	2020-2024
Lung & bronchus	Deaths	38.3	30.2	1.27xSignificant	33.2 to 44.2	2020-2024
Pancreas	New cases	17.6	13.9	1.27xSignificant	14.2 to 21.8	2019-2023
Pancreas	Deaths	14.3	11.3	1.27x	11.3 to 17.9	2020-2024
Lung & bronchus	New cases	64.7	51.8	1.25xSignificant	58.1 to 72.1	2019-2023
Brain & nervous system	Deaths	5.4	4.4	1.23x	3.3 to 8.3	2020-2024
All cancer	Deaths	169.1	143.2	1.18xSignificant	157.9 to 181.1	2020-2024
Brain & nervous system	New cases	7.3	6.2	1.18x	4.8 to 10.7	2019-2023
Kidney & renal pelvis	Deaths	3.9	3.4	1.15x	2.4 to 6.2	2020-2024
Leukemia	Deaths	6.5	5.7	1.14x	4.4 to 9.4	2020-2024
Leukemia	New cases	16.4	14.5	1.13x	12.9 to 20.6	2019-2023
Non-Hodgkin lymphoma	New cases	20.1	18.5	1.09x	16.1 to 24.8	2019-2023
All cancer	New cases	491.4	453.4	1.08xSignificant	471.4 to 512.1	2019-2023
Bladder	New cases	19.7	18.7	1.05x	16.1 to 24.1	2019-2023
Kidney & renal pelvis	New cases	18.3	17.9	1.02x	14.5 to 23	2019-2023
Non-Hodgkin lymphoma	Deaths	4.8	4.8	1x	3.1 to 7.3	2020-2024
Bladder	Deaths	3.6	4.1	0.88x	2.2 to 5.9	2020-2024
Stomach	New cases	4.9	6.6	0.74x	3.1 to 7.4	2019-2023
Thyroid	New cases	9.3	13	0.72x	6.3 to 13.2	2019-2023

Mortality measures versus the U.S. county median

Source: County Health Rankings, built from CDC National Vital Statistics System death records. The comparison value is the median of all U.S. counties.

Mortality measures for Mason County
Measure	County	U.S. median	Difference	Unit
Premature death	9,816.4	9,842.6	-0%	years of life lost before age 75 per 100,000
Life expectancy	76.6	75.3	+2%	years
Child mortality	52.4	59.8	-12%	deaths under age 18 per 100,000
Infant mortality	n/a	6.2	n/a	deaths under age 1 per 1,000 live births
Injury deaths	110.9	96.9	+14%	deaths per 100,000
Drug overdose deaths	44.6	28.6	+56%	deaths per 100,000

Air toxics and air quality

EPA AirToxScreen 2020

Lifetime cancer risk from outdoor air toxics: 20 in a million. EPA treats 100 in a million as the upper end of acceptable risk and 1 in a million as the goal.

Formaldehyde12.92 per million
Carbon Tetrachloride3.01 per million
Acetaldehyde2.13 per million
Naphthalene1.33 per million

EPA Air Quality Index 2025

Monitored on 365 days: 330 good, 1 unhealthy for sensitive groups or worse. Median AQI 23, peak 159.

Regulated facilities, sites and hazards by type

247 active records inside the county from EPA ECHO, TRI, Superfund, Brownfields, NPDES, EIA, FAA, FRA and corrections data.

NPDES wastewater discharge permit89
Rail grade crossing82
Gas station (mapped facility)26
Auto repair or body shop (mapped facility)17
Air permit holder (minor source)6
Brownfield property5
Hydroelectric plant3
Wastewater plant (mapped facility)3
Correctional facility (prison or jail)2
Heliport2
Landfill (mapped facility)2
Major air pollution source1
EPA air quality monitor1
Commercial airport1
Dry cleaner (mapped facility)1
Large greenhouse gas emitter1
Large hazardous waste generator1
Small hazardous waste generator1
Scrapyard (mapped facility)1
TRI reporting facility1
Toxic chemical release facility (TRI)1

Highest-severity records

The 25 records with the highest Envyrofax severity in the county, with the agency identifier to cite in a records request.

Shelton Wastewater Treatment Plant, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110015425100 (U.S. EPA ECHO) Agency record
Severity 6
Simpson Timber Co Front St, Shelton
TRI reporting facility. Penalties $1,000.
EPA FRS registry ID 110067420222 (U.S. EPA ECHO) Agency record
Severity 6
Simpson Timber Co Front St, Shelton
Major air pollution source. Penalties $1,000.
EPA FRS registry ID 110067420222 (U.S. EPA ECHO) Agency record
Severity 5.5
Simpson Timber Co Front St, Shelton
NPDES wastewater discharge permit. Penalties $1,000.
EPA FRS registry ID 110067420222 (U.S. EPA ECHO) Agency record
Severity 5
Sierra Pacific Industries - Shelton, Shelton
Toxic chemical release facility (TRI). Chemicals: Dioxin and dioxin-like compounds. Reports carcinogens.
TRI facility ID 98584SMPSN215NT (U.S. EPA Toxics Release Inventory)
Severity 4.5
Manke Lumber Co Inc Shelton Log Dump, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110005368752 (U.S. EPA ECHO) Agency record
Severity 4.5
Alderbrook Resort And Spa, Union
NPDES wastewater discharge permit.
EPA FRS registry ID 110006140540 (U.S. EPA ECHO) Agency record
Severity 4.5
Island Enterprises, Dba Salish Seafoods, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110006684383 (U.S. EPA ECHO) Agency record
Severity 4.5
Simpson Timber Co St Yd Sawmill 5, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110012701175 (U.S. EPA ECHO) Agency record
Severity 4.5
Kennedy Creek Quarry, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110015536945 (U.S. EPA ECHO) Agency record
Severity 4.5
Hartstene Pointe Stp, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110015546480 (U.S. EPA ECHO) Agency record
Severity 4.5
Port Blakely Co, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110015556735 (U.S. EPA ECHO) Agency record
Severity 4.5
Rustlewood Stp, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110015560935 (U.S. EPA ECHO) Agency record
Severity 4.5
South Sound Net Pens, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110015563068 (U.S. EPA ECHO) Agency record
Severity 4.5
Bayside Redi Mix, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110017840835 (U.S. EPA ECHO) Agency record
Severity 4.5
Quigg Brothers Skookum Rock Quarry, Mccleary
NPDES wastewater discharge permit.
EPA FRS registry ID 110040113542 (U.S. EPA ECHO) Agency record
Severity 4.5
Tacoma Power North Fork Skokomish Hatchery, Hoodsport
NPDES wastewater discharge permit.
EPA FRS registry ID 110059708632 (U.S. EPA ECHO) Agency record
Severity 4.5
Pacific Aquaculture Shelton Hatchery, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110059810815 (U.S. EPA ECHO) Agency record
Severity 4.5
Pay More Recycle & Salvage, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110064831491 (U.S. EPA ECHO) Agency record
Severity 4.5
Simpson Timber Co Front St, Shelton
Large greenhouse gas emitter. Penalties $1,000.
EPA FRS registry ID 110067420222 (U.S. EPA ECHO) Agency record
Severity 4.5
Alta Forest Products (Shelton), Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110071711345 (U.S. EPA ECHO) Agency record
Severity 4.5
Sand Hill Resources, Belfair
NPDES wastewater discharge permit.
EPA FRS registry ID 110015556502 (U.S. EPA ECHO) Agency record
Severity 4.3
Ace Paving Co Inc Johns Prairie Pit, Shelton
NPDES wastewater discharge permit.
EPA FRS registry ID 110040122006 (U.S. EPA ECHO) Agency record
Severity 4.3
Peninsula Sand And Gravel, Belfair
NPDES wastewater discharge permit.
EPA FRS registry ID 110039518689 (U.S. EPA ECHO) Agency record
Severity 4
Wa Dfw Hoodsport Hatchery, Hoodsport
NPDES wastewater discharge permit.
EPA FRS registry ID 110015509467 (U.S. EPA ECHO) Agency record
Severity 3.8

Correctional facilities

Prisons, jails and corrections operations with an EPA facility record, and the drinking water and wastewater compliance attached to them.

Washington Corrections Center, Shelton
EPA FRS registry ID
110005319592
Water system
WA5393063
Health-based violations
2 all time, 0 in 5 years
All violations
28
Contaminants cited
Coliform (TCR)
Wastewater permit
Yes
EPA detailed facility report
Mission Creek Corrections Center
EPA FRS registry ID
110022501390
Water system
WA5355325
Health-based violations
2 all time, 0 in 5 years
All violations
16
Contaminants cited
Coliform (TCR), Revised Total Coliform Rule
Wastewater permit
None on record
EPA detailed facility report

Discovery / public records

Records to request for Mason County

Washington state cancer registry
Cancer incidence counts by census tract or ZIP code, by cancer type and year (de-identified). Any cancer cluster inquiries or investigations in Mason County, and their findings.
Washington vital statistics office
Death certificate counts by cause of death and residence tract or ZIP code, and the years behind the mortality measures above.
Washington health department, environmental epidemiology
Health consultations or assessments by ATSDR or the state health department covering the county, and any exposure investigations.
Washington environmental agency and the U.S. EPA regional office
Compliance history, inspection reports, notices of violation, penalties and enforcement actions for each facility above, cited by EPA FRS registry ID.
Washington drinking water program
Violation notices, sampling results and sanitary surveys for the public water systems serving the county, including any system serving a correctional facility.
Department of corrections or county sheriff
Water testing, grievances and environmental health inspections for the correctional facilities listed above.

Each Envyrofax address report includes a printable records request worksheet with the custodian and the exact request wording per finding.

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