Abstract
Introduction: Workers in aluminum production are exposed to a complex mixture of different particles and gases that are potentially harmful to the airways. We have established a method for controlled particle exposure in a human exposure chamber. We aimed to examine the effect of short term exposure to aluminum oxide (Al2O3) on lung function and inflammatory markers in induced sputum in healthy volunteers.
Methods: Fifteen healthy volunteers (all males, age 19-31) were exposed to an atmosphere of fused Al2O3 particles in the range of 3.8-4.0 mg/m3 for two hours including 30 min of exercise (stationary bike). Also a sham exposure was performed at least two weeks apart from the Al2O3 exposure. Spirometry was carried out, and induced sputum and blood samples were collected 48 hours before, 4 and 24 hours after exposure.
Results: Mean (+/- SEM) percentage sputum neutrophils was increased 24 hours post vs pre Al2O3 exposure (43% (4) vs 31% (4), p=0.01). No significant neutrophil response was observed with sham exposure. No differences were seen in fibrinogen levels and differential cell counts in blood before and after Al2O3 exposure. cDNA microarray (mRNA) analysis of sputum samples showed significantly increased levels after Al2O3 exposure for genes that play a role in the regulation of coagulation processes, lipid metabolism, DNA replication, cellular development and repair, and cell to cell signaling.
Conclusion: The present study suggests that controlled exposure to Al2O3 particles induces neutrophilic inflammation in the airways, and increased expression of genes associated with several disease processes. Al2O3 exposure had no effect on markers of systemic inflammation.
- Copyright ©ERS 2015
