US Lung Transplants for Work-Related Lung Diseases Are Increasing

By Carolyn Crist

October 13, 2020

NEW YORK (Reuters Health) - Lung transplants for work-related lung diseases are becoming more common in the U.S., particularly among coal workers who face hazardous conditions on the job, according to a new study.

After years in the coal industry, workers may be diagnosed with pneumoconiosis, silicosis, asbestosis and other severe lung-related conditions that are untreatable and could become life-threatening, researchers note in the journal Occupational and Environmental Medicine.

"Unlike lung diseases with genetic causes, work-related lung diseases such as silicosis and black lung are completely preventable," said lead author Dr. David Blackley of the National Institute for Occupational Safety and Health in Morgantown, West Virginia.

"Lung transplants for these diseases are increasingly common, so it is critical that we understand their causes and consequences to help prevent future cases," he told Reuters Health by email. "Donor lungs are a limited resource."

Dr. Blackley and colleagues analyzed national registry data between 1991 and 2018 to understand how many patients received lung transplants for work-related lung diseases. They looked for pneumoconiosis, commonly called "black lung disease," which is caused by inhaling dust particles found in coal mines over an extended period of time. They also looked for silicosis and asbestosis, which are caused by breathing in silica and asbestos particles also found in mines and fabrication occupations.

Overall, the frequency of lung transplants increased over time, and more than half occurred during the last decade. Among the 230 transplants, 79 were for pneumoconiosis and 78 were for silicosis. Most patients came from West Virginia, Kentucky, Virginia, Pennsylvania and Wisconsin.

On average, workers received a transplant around age 56. Patients with metal pneumoconiosis, which is a rare and serious form of lung disease caused by inhaling dust from hard metals such as tungsten or cobalt, received transplants at younger ages, with an average around age 49. In comparison, patients with asbestosis received a transplant around age 62.

After a transplant, patients with pneumoconiosis survived for an average of 6.6 years. Those with asbestosis lived for an average of 8.2 years, and those with silicosis lived for an average of 7.8 years.

Each lung transplant costs about $1.2 million on average, and more than half of the transplants included in the study were covered by public health insurance such as Medicare or the Black Lung Disability Trust Fund, which is more than $4 billion in debt, Dr. Blackley said.

Although the severe form of black lung was nearly eradicated in the U.S. by the early 1990s, a concerning number of transplants are still occurring 30 years later, he added.

"The prevalence of severe black lung has reached an all-time high, and we expect more lung transplants to occur," he said. "Prevention of harmful workplace exposures and earlier detection of disease . . . are imperative."

The increase in lung transplants could be due to complacency in workplace-related exposures in many industries during the past few decades, said Dr. Ryan Hoy of the Monash University Center for Occupational and Environmental Health in Melbourne, Australia. Dr. Hoy, who wasn't involved with this study, researches silicosis among workers who produce countertops from engineered stone materials.

"The fact that these workers . . . have developed such severe lung disease suggests that medical monitoring of at-risk workers is also failing," he said. "When a potentially hazardous substance such as silica is present at a workplace, medical monitoring is critically important to identify signs of disease at the earliest possible stage, well before symptoms have developed."

The increase in both work-related lung disease and transplants should be a "serious wake-up call" to reduce exposures and prevent diseases that aren't treatable, said Dr. Cecile Rose of National Jewish Health in Denver, Colorado.

Dr. Rose, who wasn't involved with this study, has researched severe silicosis and lung transplants among stone fabrication workers in California, Colorado, Texas and Washington in the past few years.

"The human tragedy that results from end-stage lung disease - where the patient simply cannot breathe without a struggle - cannot be over-stated," she told Reuters Health by email. "Besides the human costs, the societal costs are overwhelming and unacceptable."

SOURCE: Occupational and Environmental Medicine, online October 2, 2020.