Effects of occupational exposure to poorly soluble forms of beryllium on biomarkers of pulmonary response in exhaled breath of workers in machining industries

Objective: To analyze the effects of occupational exposure to poorly soluble forms of beryllium (Be) on biomarkers of pulmonary inflammation using exhaled breath condensate (EBC) in workers employed in machining industries.
Methods: Twenty machining operators were compared to 16 controls. The individual exposure to Be was assessed from the work history with several indices of exposure calculated on the basis of task-exposures matrices developed for each plant using historical air measurements. Clinical evaluation consisted in a medical questionnaire, measurements of biomarkers in EBC (tumor necrosis factor alpha (TNF-á), total nitrogen oxides (NOx)), measurement of the fraction of exhaled nitric oxide (FeNO) and resting spirometry. Adjusted multiple linear regressions were used to study the effect of the exposure to Be on inflammatory biomarkers.
Results: Levels of TNF-á and NOx in EBC were not statistically different between exposed and controls. We found a statistically significant relationship between levels of TNF-á in EBC and both index of cumulative exposure and duration of exposure to Be. No other statistically significant relationships were found between exposure to Be and pulmonary response.
Conclusion: Our results suggest that machining-related exposure to Be is related to pulmonary inflammation involving TNF-á. These findings must be confirmed by larger studies.
Keywords: beryllium; exhaled breath condensate; tumor necrosis factor alpha; occupational exposure; machining.