Actually they are dying, just very slowly. Lung diseases continue to increase. More people measured to have elevated levels of CO. Most people think of COPD as a problem getting enough air in. Actually it's a problem of getting the CO2 out. Various conditions of fibrosis are higher. Classifying it is difficult, but damage caused by an identifiable outside matter fits under Hypersensitive Pneumonitis.
The problem is that in most cases you can't tell how much was from one cause and how much from another. Still cigarettes are by far the leading cause of lung disease, but could exposure to diesel exhaust on top of that make the risk higher? Perhaps instead it's on top of exposure to some other agent like Formaldehyde.
The longer we live, the more these factors enter into the equation since much of it is cumulative effect.
From the National Institute of Health, I quote:
Diesel exhaust particulates are listed as "reasonably anticipated to be a human carcinogen" in the Thirteenth Report on Carcinogens published by the National Toxicology Program because long-term exposure to diesel exhaust may cause lung cancer and other lung damage.
Long-term exposure to diesel exhaust can cause chronic respiratory symptoms such as persistent cough and mucous, bronchitis, and reduced lung capacity. Long-term exposure to diesel fuel vapors can cause kidney damage and lower the blood’s ability to clot. Swallowing diesel oil can cause collapse, rapid low blood pressure, and loss of vision.
In combination with other cancer-causing substances, such as cigarette smoke, welding fumes, and asbestos, long-term exposure to diesel exhaust can increase your risk of developing lung cancer.
If you have asthma, emphysema, heart disease, or allergies, exposure to diesel exhaust can worsen those symptoms.
For more information,
https://toxtown.nlm.nih.gov/text_version/chemicals.php?id=11
