Black lung increase may even be underreported

The article and editorial in the Sunday, Feb. 11 paper are important reminders that black lung is not a disease that has been eradicated.

As a chest radiologist on the faculty of the University of Louisville School of Medicine, I receive referrals for chest x-rays to be used as a second opinion for the evaluation of coal workers.

During 2013 and 2014, I provided a reading of chest x-rays for 64 miners with disability claims. While this is a smaller number compared with the radiologist in Pikeville, I found the percentage of these patients with abnormal x-rays to be startling.

Ten had progressive massive fibrosis and 27 had simple pneumoconiosis, with only 30 having a normal chest x-ray.

Your article focused on progressive massive fibrosis which is the most advanced disease, but simple pneumoconiosis is not harmless. It may be a sign of less exposure, but it may also be the result of early disease that may progress over a period of years to progressive massive fibrosis. Even the 30 patients with the normal chest x-ray are not assured that they will not have problems in the future.

The Coal Workers’ Pneumoconiosis (CWP) surveillance program was started in 1970 under the guidelines of the International Labor Organization (ILO) in Geneva, Switzerland. Participating countries included the U.S., Germany, Japan and Finland.

The U.S. program is administered by the National Institute for Occupational Safety and Health (NIOSH) branch of the Centers for Disease Control. Radiographic standards for classification of CWP, silicosis and asbestosis were developed by the ILO and were updated in 2000. The patient’s chest x-ray is compared with the ILO standards for a “B” reading. The “B” reading was designed as an epidemiologic tool, but has been extensively utilized in compensation claims.

The U.S. prevalence of CWP was 11 percent in 1970 and declined to 2 percent by 1995, but increased to 3.6 percent by 2000. In 2006, the CDC reported advanced cases with rapid progression and death from progressive massive fibrosis in young miners with apparently low levels of dust exposure.

Nine percent of the miners screened in the NIOSH program from 2005-2009 had coal workers’ pneumoconiosis. But in 2014, the researchers reported that the worst form of the disease had spiked to the highest level in 40 years.

NIOSH only uses chest x-rays for the surveillance program which are not as sensitive for the detection of lung disease as a CT scan. It is possible that a CT scan would have shown evidence of early disease in some of the 30 patients with normal chest x-rays.

I am not recommending CT for the evaluation of coal workers pneumoconiosis, but want to emphasize that the very early stages of coal workers pneumoconiosis are not detectable on the chest x-ray. Patients with symptoms should have annual follow-up chest x-rays to detect progression of their disease.

The dust is trapped in the lungs and the scarring does not stop. This is a progressive disease for the remainder of the patient’s life.

This story was originally published February 16, 2018 at 6:07 PM with the headline "Black lung increase may even be underreported."