Exhaled breath malondialdehyde, spirometric results and dust exposure assessment in ceramics production workers

The study aimed at measuring exhaled breath malondialdehyde (EBC-MDA) in workers exposed to dust containing
silica and at its comparison with the non-exposed control group. Material and Methods: The cross sectional, case-control
study (N = 50) was performed in a tile and ceramics production factory in Yazd, Iran. EBC-MDA was quantified in exhaled
breath of the participants by a lab made breath sampler. Exposure intensity was measured according to the NIOSH 0600
method in selected homogeneous exposure groups. Additionally, spirometry test was conducted to investigate a correlation
between EBC-MDA and spirometric findings in the exposed workers. Results: There was no difference in the observed exposure
intensities of silica containing dust in different units. However, “coating preparation” was the unit with the highest
concentration of dust. Although, the level of EBC-MDA in the cases was slightly higher than in the controls, the difference
was not statistically significant (U = 252, p = 0.464). A significant and positive correlation was found between dust exposure
intensity in working units and the measured EBC-MDA of workers (r = 0.467, N = 25, p = 0.027). There were also no
statistically significant differences among job categories in the exposed group for the values of FEV1% (F(3, 44) = 0.656,
p = 0.584), FVC% (F(3, 44) = 1.417, p = 0.172), and FEV1/FVC% (F(3, 44) = 1.929, p = 0.139). Conclusions: The results
showed a significant correlation between respirable dust exposure intensity and the level of EBC-MDA of the exposed subjects.
However, our results did not show a significant correlation between lung function decreases and EBC-MDA.