Most Cases in the Country: California Mesothelioma by the Numbers
California leads the US in total mesothelioma cases. CDC data on diagnoses, deaths, and exposure across LA, San Francisco, and 42 natural asbestos counties.
California’s mesothelioma burden is the largest of any state by raw numbers. With 284 new cases confirmed in 2021 by CDC primary data, the state accounts for more diagnoses than any other in the nation. The reasons are both industrial and geological: a century of shipyard, refinery, and construction exposure combined with naturally occurring asbestos deposits spanning 42 of the state’s 58 counties.
The scale of the problem is visible in the death toll. Between 1999 and 2022, 5,748 people in California died from mesothelioma. Thousands more died from asbestosis, lung cancer, and other asbestos-related diseases. Every major metro area is affected, and the exposure pathways are still active in buildings, soil, and infrastructure built before the 1980s.
State Rankings
For a full comparison of all 50 states, see our mesothelioma rates by state rankings.
| Metric | California | National |
|---|---|---|
| New cases (2021, CDC primary) | 284 (highest raw total) | 2,669 |
| Diagnoses (1999-2022) | 7,736 | ~60,000 |
| Mesothelioma deaths (1999-2022) | 5,748 | ~62,000+ |
| Counties with natural asbestos | 42 of 58 | Limited to a few states |
| Statute of limitations (PI) | 1 year from diagnosis | Varies by state |
County-Level Data
Los Angeles County leads the state with an estimated 4,979 asbestos-related deaths through the most recently reported period, averaging roughly 262 per year. This reflects a century of industrial activity, from the San Pedro shipyards and Long Beach Naval Shipyard to the refineries along the 710 corridor and the massive postwar construction boom that used asbestos in virtually every commercial building.
Contra Costa County’s elevated death toll is driven almost entirely by the concentration of oil refineries along the Carquinez Strait. Chevron, Shell, and other operators ran facilities where asbestos insulation was standard on pipes, boilers, and processing equipment for decades. The Bay Area counties and San Diego metro area also show elevated rates from shipyard, refinery, and military exposure.
Where Exposure Happened
California’s asbestos burden traces to four primary sources.
Shipyards
San Francisco’s Hunters Point Naval Shipyard, the Mare Island Naval Shipyard in Vallejo, and the Long Beach Naval Shipyard were among the busiest military shipyards on the West Coast. Tens of thousands of workers built, maintained, and decommissioned vessels in enclosed environments where asbestos was present in insulation, pipe covering, boiler lagging, and fireproofing. Hunters Point remains a Superfund site. Similar shipyard exposure drove elevated rates at the Brooklyn Navy Yard in New York, the Jacksonville and Pensacola yards in Florida, and the Savannah port facilities in Georgia.
Oil Refineries
The Bay Area’s refinery corridor, stretching from Richmond through Martinez and Benicia, and the refineries in the LA Basin and Long Beach used asbestos insulation extensively. Pipefitters, boilermakers, and maintenance workers who kept these facilities running were exposed to asbestos fibers throughout their careers.
Naturally Occurring Asbestos
California is one of the few states where asbestos occurs naturally in the geological formations. The mineral has been identified in 42 of 58 counties, with concentrations in the Sierra Nevada foothills, the Coast Ranges, and parts of Southern California. Construction, road building, and land grading in these areas can disturb asbestos-bearing rock and release fibers into the air.
Construction and Military
The postwar building boom in Southern California used asbestos-containing materials in virtually every commercial and residential structure built between the 1940s and 1980s. Military installations, from Camp Pendleton to Travis Air Force Base, added another layer of occupational exposure for service members and civilian workers.
Who Is Most at Risk
- Shipyard workers at Hunters Point, Mare Island, Long Beach, and San Pedro
- Oil refinery workers in the Bay Area and LA Basin
- Construction tradespeople working in pre-1980 buildings statewide
- Military veterans stationed at California bases and shipyards, who face elevated risk across all service branches
- Pipefitters and insulators across all industrial sectors, one of the highest-risk occupational groups nationally
- Residents near natural asbestos deposits in the Sierra Nevada foothills and Coast Ranges
Consistent with the 20 to 60-year latency period between exposure and diagnosis, the majority of California mesothelioma deaths occur in people aged 60 and older. Nationally, approximately 87% of diagnoses fall in this age group, per CDC data for 1999-2019.
California has a one-year statute of limitations for personal injury claims, running from the date of diagnosis. Wrongful death claims must be filed within one year of the date of death. This is one of the shortest filing windows in the country. Families should consult an attorney immediately after diagnosis to preserve their legal options.
Legal Landscape
For an overview of all current treatment options, see the 2026 mesothelioma treatment landscape. California’s asbestos trust fund claims are relevant across all exposure industries. Shipyard workers, refinery workers, and construction tradespeople were exposed to products from dozens of manufacturers, many of which have established bankruptcy trusts that still accept claims.
Verdicts and settlements in California reflect both the state’s industrial diversity and its plaintiff-favorable legal environment, with some of the largest mesothelioma awards in the country originating from California courts.
References
Centers for Disease Control and Prevention. CDC USCS Mesothelioma Report.
https://www.cdc.gov/united-states-cancer-statistics/publications/mesothelioma.html
Centers for Disease Control and Prevention. CDC WONDER Mortality Database.
https://wonder.cdc.gov/
California Department of Conservation. Naturally Occurring Asbestos in California.
https://www.conservation.ca.gov/cgs/minerals/asbestos
Didier et al. 2025, PMC. Mesothelioma Mortality Trends in the United States.
https://pmc.ncbi.nlm.nih.gov/articles/PMC12005915/
Reader Q&A
Frequently Asked Questions
Why does California have the most mesothelioma cases?
California’s large population, extensive shipyard and refinery operations, massive postwar construction boom, and naturally occurring asbestos in 42 counties combine to produce the highest raw case count of any state. The exposure sources are both occupational and environmental.
What is the statute of limitations for mesothelioma in California?
California has a one-year statute of limitations for personal injury claims, starting from the date of mesothelioma diagnosis. Wrongful death claims must also be filed within one year of the date of death. This is among the shortest deadlines in the country.
Is naturally occurring asbestos still a risk in California?
Yes. Naturally occurring asbestos has been identified in 42 of 58 California counties. Construction, grading, and development in these areas can disturb asbestos-bearing rock and release fibers. The California Air Resources Board regulates activity in these areas, but the geological risk is permanent.
Are mesothelioma cases still being diagnosed in California?
Yes. California continues to record the most diagnoses of any state. Because mesothelioma has a latency period of 20 to 60 years, people exposed in the 1960s through 1980s are still receiving diagnoses today.
What are the odds of getting mesothelioma?
The incidence of malignant mesothelioma in the United States is 0.6 cases per 100,000 people annually, with about 2,800 new cases reported in 2022. Among people with heavy, prolonged asbestos exposure, 2-13% develop the disease, while only 2-10% of those with prolonged exposure do so. Rates are higher in males (1.1 per 100,000) than females (0.3 per 100,000), peaking at 16.9 per 100,000 in men aged 85-89. Mesothelioma remains rare overall, even among those exposed.
Is mesothelioma 100% fatal?
Mesothelioma has a very poor prognosis, with a median survival of approximately one year from diagnosis and a five-year survival rate of 10-12%. However, it is not universally 100% fatal. Some people with mesothelioma have survived for extended periods with multimodal treatment (surgery, chemotherapy, and radiation), and survival outcomes vary significantly based on cancer stage, histological type, and individual response to treatment. Peritoneal mesothelioma, for example, shows better one-year survival rates (92%) compared to pleural mesothelioma (approximately 40% 1-year survival per SEER), suggesting that type and early detection can influence outcomes. While the disease remains highly aggressive and fatal in the majority of cases, advances in treatment protocols continue to improve survival rates incrementally.
Is mesothelioma one of the worst cancers?
Mesothelioma ranks among the deadliest cancers due to its low 5-year survival rate of 7.2-12% across stages, lower than most others except pancreatic cancer at 7.3%. Localized pleural mesothelioma, the most common type affecting over 75-80% of people with the disease, has a 20% 5-year survival rate, dropping to 8% for distant spread. Median life expectancy after diagnosis ranges from 12-21 months with treatment, often shorter without it, reflecting its aggressive nature linked to asbestos exposure. Factors like stage at diagnosis and treatment access influence individual outcomes.