(Reuters Health) — Workplace exposure to vapours, gas, dust and fumes increases the likelihood that a CT scan will show early signs of disease in the lung tissue, according to a United States study.
“Interstitial lung disease is a family of over 100 diseases each characterized by inflammation and/or scarring (fibrosis) in the walls of the air sacs (alveoli) of the lungs,” said study co-author David Lederer, who co-directs the Interstitial Lung Disease Program at Columbia University Medical Center in New York.
The causes of interstitial lung disease (ILD) are often unclear.
"Our research group has been studying the causes of the earliest changes in the lungs that precede the development of clinically evident (symptomatic) ILD,” Lederer said.
ILDs include “black lung” from working in coal mines, asbestosis from asbestos exposure and pulmonary sarcoidosis, Lederer noted.
“Other examples include ILD resulting from autoimmune conditions such as scleroderma and rheumatoid arthritis, and ILD resulting from exposure to mould in the home or workplace.”
To get a sense of what role workplace exposures might play in changes that are visible on a lung scan, but may not yet produce symptoms, researchers analyzed data from a large study of cardiovascular disease in adults in six cities: Baltimore, Chicago, Los Angeles, New York and St. Paul, Minn. and Winston Salem, N.C.
The 5,702 study participants had chest CT scans at the start of the study and again six years later. They also reported their work exposure to vapours, gas, dust and fumes, and the researchers drew exposure estimates from data created by the National Institute for Occupational Safety and Health (NIOSH).
Participants with higher exposure scores based on the NIOSH job exposure matrix were likely to have more opaque areas typical of ILD, known as high attenuation areas, especially with dust or gas exposure.
Self-reported exposure to vapour or gases was also linked with an almost doubled risk of interstitial lung abnormalities, the authors reported in the American Journal of Respiratory and Critical Care Medicine.
Lederer noted that “subclinical ILD occurs before the onset of symptoms, and not all subclinical ILD progresses to the point of developing symptoms.”
In this study, workplace exposures could not be consistently tied to worsening lung problems.
When symptoms do develop, the most common ones are breathlessness during exertion and dry cough (meaning a cough without significant production of sputum or phlegm), he said.
“These symptoms worsen over time and in moderate to severe disease, people living with ILD are prescribed oxygen. Despite the use of oxygen and other treatments, fibrotic forms of ILD eventually become life-threatening,” he added.
The Pulmonary Fibrosis Foundation estimates that 40,000 Americans die from ILD each year.
Lederer said the first step in preventing these exposures is to talk to your doctor about the conditions of your workplace and possible exposures in the workplace.
"Workers should obtain the generic names of any chemicals and other agents in the workplace, and either the worker or the patient should obtain Material Safety Data Sheets (MSDS) for each agent,” he said.
In some cases, MSDS’s can be found online, but each employer should also be able to provide them to workers. A review of these MSDS’s can identify whether a particular exposure has been linked to lung disease, Lederer said.
“Workers should also follow the instructions given by their employer regarding the use of personal protective equipment, such as masks, gloves, and respirators,” he said.