They knew. That’s the damning conclusion drawn from thousands of internal documents, corporate memos, and suppressed medical studies that emerged from asbestos litigation over the past five decades. The asbestos industry didn’t just fail to warn workers about the dangers of their products—they actively concealed evidence that asbestos was killing people.
The paper trail begins not in the 1970s when regulations finally arrived, but in the 1930s. For more than 40 years, asbestos manufacturers possessed clear evidence that their products caused fatal disease. They chose profits over lives.
The Sumner Simpson Papers
The most damning evidence comes from correspondence between executives at Raybestos-Manhattan and Johns-Manville, two of the largest asbestos manufacturers in America.
In 1935, Sumner Simpson, president of Raybestos-Manhattan, wrote to Vandiver Brown, an attorney for Johns-Manville, about a study they had commissioned on worker health. The study found alarming rates of lung disease among asbestos workers.
Simpson’s response wasn’t to warn workers. It was to suppress the findings.
“It is our policy,” Simpson wrote, “to do everything possible to minimize the hazards of asbestos dust without disclosing the potential liability.”
In another letter, he was more explicit: “The less said about asbestos, the better off we are.”
These weren’t low-level employees. These were company presidents and chief legal counsel, making deliberate decisions to hide evidence of harm.
The Saranac Laboratory Cover-Up
In the 1930s, Johns-Manville and other asbestos companies funded medical research at Saranac Laboratory in New York—one of the premier occupational health research facilities in the country.
The researchers found exactly what the companies feared: asbestos caused a progressive, fatal lung disease. Workers exposed to asbestos dust were dying at alarming rates.
The companies’ response was to control the research:
- They required approval of any publication before release
- They edited out findings they considered “unfavorable”
- They delayed publication for years
- They terminated researchers who pushed for transparency
Dr. Leroy Gardner, the lead researcher, grew frustrated with the interference. In letters that later emerged in litigation, he complained that the companies were preventing him from publishing life-saving findings.
When Saranac’s studies were finally published, they had been so heavily edited by company lawyers that the conclusions were meaningless. The original data showing clear evidence of asbestos disease was removed or softened beyond recognition.
”We Save a Lot of Money”
Perhaps the most chilling document emerged from Metropolitan Life Insurance Company, which provided coverage to many asbestos companies.
In 1931, a MetLife official noted that insurance claims from asbestos workers were rising dramatically. His proposed solution wasn’t to address the hazard—it was to exclude asbestos-related claims from policies.
A follow-up memo calculated the cost-benefit analysis of worker safety:
“We could spend money to reduce dust exposure, or we could accept that some workers will die. The latter approach saves a lot of money in the short term.”
The memo recommended the latter approach.
The Timeline of Deception
1918
Insurance studies first link asbestos to lung disease
1930
British medical journal Lancet publishes asbestos-disease connection
1931
Raybestos and Johns-Manville commission internal health studies
1935
Simpson-Brown correspondence: “The less said about asbestos, the better”
1936
Saranac Laboratory findings edited and suppressed
1943
Nazi Germany bans asbestos as workplace hazard—U.S. does nothing
1964
Dr. Irving Selikoff publishes definitive study on asbestos cancer link
1971
First OSHA standards for asbestos exposure (41 years after industry knew)
1978
EPA begins regulating asbestos products
2024
EPA finally bans remaining asbestos uses in the United States
The “Acceptable Risk” Memo
In 1966, an internal memo at a major asbestos manufacturer (later revealed in litigation) discussed the “acceptable risk” of worker deaths.
The calculation was coldly mathematical: How many workers dying from asbestos disease could the company absorb in legal costs, versus the cost of implementing proper safety measures?
The memo concluded that it was cheaper to let workers die and pay out settlements than to fix the problem.
“These are chosen risks,” the memo stated. The workers hadn’t chosen anything—they didn’t know the risks existed.
Why Workers Didn’t Know
If the companies knew asbestos was deadly, why didn’t the workers?
No warning labels: Despite clear internal knowledge, asbestos products carried no health warnings until the 1970s. Workers handled raw asbestos with bare hands, cut asbestos boards with power saws, and mixed asbestos cement without respirators.
Suppressed medical exams: Some companies conducted chest X-rays of workers but never told them the results. Workers with visible lung damage were simply transferred to other departments or laid off “for cause” unrelated to health.
Industry propaganda: The asbestos industry funded front groups that published materials claiming asbestos was safe when handled “properly”—a meaningless reassurance given that no safety equipment was provided.
Union complicity: Some unions, compromised by industry influence, failed to push for safety measures that might cost jobs.
The Documents Emerge
The cover-up began to unravel in the 1970s, when attorneys representing dying asbestos workers started winning discovery motions that forced companies to release internal documents.
What emerged was a paper trail of deliberate deception spanning decades:
- Corporate correspondence discussing how to hide health data
- Edited research studies with damaging findings removed
- Memos calculating the cost of dead workers versus safety measures
- Meeting minutes showing executive decisions to suppress warnings
These documents became the foundation of asbestos litigation that has resulted in over $30 billion in settlements and verdicts.
What the Cover-Up Cost
The human toll of the asbestos cover-up is staggering:
| Metric | Estimate |
|---|---|
| Americans killed by asbestos diseases | 230,000+ |
| Current annual U.S. mesothelioma deaths | ~3,000 |
| Years of suppressed knowledge | 40+ |
| Asbestos trust fund payouts to date | $30+ billion |
Every death from mesothelioma diagnosed today can be traced, in part, to decisions made in corporate boardrooms 90 years ago.
The Lesson That Keeps Repeating
The asbestos cover-up established a template that other industries would follow:
- Tobacco: Knew about cancer risks decades before admitting them
- Opioids: Knew about addiction potential while marketing as “non-addictive”
- PFAS/Forever chemicals: Knew about environmental persistence and health risks
In each case, the playbook was similar: Fund research you can control. Suppress unfavorable findings. Calculate the cost of harm versus the cost of honesty. Choose profits.
The asbestos documents remain required reading in corporate ethics courses—not as an example of how things used to be, but as a warning about how corporations still behave when profits conflict with public health.
Despite everything we know, asbestos is still not fully banned in the United States. The EPA’s 2024 ban only covers chrysotile asbestos—other forms remain in use. And in countries like Russia, Brazil, and China, asbestos mining and manufacturing continue at scale.
Related Reading
When did asbestos companies first know about health risks?▼
Internal documents show that major asbestos manufacturers knew about serious health risks by the early 1930s. The Sumner Simpson correspondence from 1935 explicitly discusses suppressing health findings. Insurance company studies linked asbestos to lung disease as early as 1918.
Why weren't workers warned about asbestos dangers?▼
Company documents reveal a deliberate strategy to suppress warnings. Executives calculated that the cost of safety measures and potential lost sales outweighed the cost of worker illness and death. Products carried no warning labels until the 1970s—four decades after companies had clear evidence of harm.
How were the cover-up documents discovered?▼
The documents emerged through legal discovery in asbestos lawsuits beginning in the 1970s. Attorneys representing sick workers won court orders forcing companies to release internal correspondence, research studies, and corporate memos that had been kept secret for decades.
Has anyone been criminally prosecuted for the cover-up?▼
No executives have faced criminal prosecution for the asbestos cover-up, despite clear evidence of decisions that led to thousands of deaths. The companies have faced civil liability totaling over $30 billion, but individual accountability has been limited to civil lawsuits.