Railroad diesel exhaust exposure and cancer risk

American railroads moved from coal to diesel in a short span. Diesel locomotives grew from 10% of the fleet in 1946 to 95% by 1959, which means most contact with railroad diesel exhaust began in the 1950s.

The train crews were the jobs researchers counted as diesel-exposed:

• Engineers
• Firemen
• Conductors
• Brakemen

In the main railroad worker study, lung cancer death risk was highest for employees who worked on operating trains.

Yes, it causes lung cancer. In 2012, the World Health Organization's International Agency for Research on Cancer put diesel engine exhaust in its most certain category. That category, Group 1, is used for agents proven to cause cancer in people.

The specialists who made that call spent a week together, and all of them agreed on lung cancer. They also saw limited evidence tying it to bladder cancer. They listed diesel trains, ships, and power generators among exposure sources.

Before 2012, the agency called diesel exhaust only a probable cancer cause, a rating from 1988. In March 2012, a big US study of miners working underground reported that the chance of lung cancer climbed with more exposure, even after cigarette smoking was taken into account.

Researchers kept up with roughly 55,000 railroad workers in the US who were 40 to 64 in 1959, and noted who died through 1996. To estimate exposure, they used the job each person held in 1959, since railroad workers often remain in the same role. Among 43,600 deaths, lung cancer caused 4,277.

Diesel-exposed workers were more likely to die of lung cancer than workers of the same age who had no exposure. The youngest group had logged the greatest number of diesel-exposed years after 1959.

A figure above 1 means a higher chance of dying of lung cancer than unexposed workers of the same age.

An earlier review of these workers linked train-operating jobs to a 40% higher lung cancer risk, with a 59% higher risk for engineers in the 40-to-44 starting group. There, more years on the job did not mean higher risk. Even so, the authors said diesel exhaust played a part in lung cancer deaths in this group of workers.

State workers' compensation does not cover railroad workers. Instead, FELA, the Federal Employers' Liability Act, lets them seek payment from the railroad for what they lost. A railroad can be responsible when an injury or death comes even partly from its carelessness.

The Supreme Court said FELA reaches work-related illness, not just sudden accidents. The railroad's carelessness needs only to have helped cause the harm, even slightly.

A worker who was partly at fault may still recover money under FELA. The jury reduces the award by that person's share of blame. Nor is the worker treated as having taken on the job's dangers when railroad carelessness caused the harm.

Money from a FELA claim can cover medical bills, wages you've lost and will lose, and your pain and suffering. The free review asks about where and when you worked, your job titles, and when a doctor first linked your illness to work.

A FELA lawsuit has to be filed inside three years. For an illness that builds slowly, the clock starts when the exposure's effects become apparent, not at the time of the exposure.

Timing can affect whether a claim can proceed. In January 2026, a New Jersey appeals court ruled that a car inspector's claim for bladder cancer as it existed in 2014 was filed too late. His doctor had linked the cancer to workplace exposure in May 2014, and he filed in April 2019, beyond the three-year limit.

Jurors awarded $21.8 million to the relatives of a man who died following 38 years at Norfolk Southern. Witnesses said workers learned how to use respirators yet never received them while working in diesel exhaust. Even as studies were showing the fumes caused cancer, the company was telling its workers something different. Before trial, the railroad's final offer was $4,000, while the family's final demand was $1,000,000.