Respiratory complications are a common indicator of asbestos-related diseases. Restricted pulmonary function is one such symptom that affects a large percentage of people with past asbestos exposure.

A 2010 study published in the Journal of Occupational Medicine and Toxicology explored the pulmonary abnormalities experienced by both smoking and non-smoking asbestos workers. Pulmonary function tests were taken by 277 workers with prior chrysotile asbestos exposure and results were compared with a control group of 177 unexposed participants.

The participants with asbestos exposure were selected from an asbestos textile factory in Southwest China. All were male and had worked in the asbestos-laden environment for at least two years. None of the participants had been diagnosed with malignant mesothelioma or any clinical disorder other than pneumoconiosis.

Of the control group, more than 80 percent of participants had normal pulmonary function. Only half of the asbestos workers were found to have normal pulmonary function. The asbestos workers had higher proportions of obstructive, restrictive and mixed patterns of pulmonary dysfunction.

Obstructive impairment, in which the bronchial tubes become too narrow for normal flow, was 2.5 times higher in the asbestos-exposed group. Restrictive impairment, where lung expansion is impaired, was also 2.2 times higher in the group of asbestos workers. Both of these conditions were thought to be significantly triggered by asbestos exposure.

Among the subjects with a history of exposure to asbestos, 36 percent displayed radiographic changes consistent with the development of emphysema, and 31 percent displayed similar changes indicative of asbestosis. Test results that implied the simultaneous development of both asbestos and emphysema were presented by 15 percent of participants.

The researchers concluded that asbestos exposure substantially contributed to the patients’ airway impairment. A higher percentage of older patients and smokers in the asbestos-exposed group was recognized as a potential factor in the results, yet standardized testing and interpretation criteria were applied during this study to ensure unbiased results.