Non-Invasive Assessment of Airway Inflammation in Ship-Engine Workers

Abstract

Smoking is harmful for respiratory function. In young to middle-aged men the damage is insidious and difficult to demonstrate. The respiratory impairment could increase under specific stressful conditions in the professional environment. On the hypothesis that exhaled markers are useful for assessing airway susceptibility to inhaled irritants, we measured exhaled markers and lung function in smoking and non-smoking engine-driver military coastguards before and after a patrol at sea. Eighteen men, mean age 39 yrs (range 23-58 yrs), 8 smokers, underwent spirometry, exhaled and nasal nitric oxide (eNO, nNO), exhaled carbon monoxide (CO) and exhaled breath condensate (EBC) for measures of hydrogen peroxide (H2O2), leukotriene B4 (LTB4), proteins (Prots), 8-isoprostanes (8-IsoPs), nitrite (NO2-) and nitrosothiols (RS-NOs) at baseline and after an 8-hour patrol navigation on board small, high-speed diesel-powered ships. At baseline, the smokers showed higher middle flows and CO levels, lower eNO and nNO than non-smokers, but similar levels of EBC markers; geometric means (95% confidence interval), CO: 23.6 (14.5 to 38.3) vs. 3.5 (2.5 to 5.3) ppm; eNO: 7.9 (4.8 to 12.9) vs. 26.7 (15.7 to 45.5) ppb, p=0.000. After navigation, Prots, 8-IsoPs and RS-NOs (but not lung function variables or other markers) significantly increased only in smokers; baseline vs post-navigation RS-NOs: 0.27 (0.11 to 0.65) vs. 1.30 (0.58 to 2.89) micromol, p=0.012. The respiratory consequences of a stressing environment in engine-driver military coastguards who actively smoke are better assessed by measuring EBC markers than by eNO, nNO or lung function. By increasing airway inflammation from oxidative-stress, tobacco smoking appears to interact with other chemical or physical factors elicited during sea navigation. Precisely what these factors are deserves further investigation.

Reference Ranges of 8-Isoprostane Concentrations in Exhaled Breath Condensate (EBC): A Systematic Review and Meta-Analysis

“…We therefore analyzed 8-isoprostane levels according to gender but found no statistically significant difference between males and females. There were only nine studies out of 52 [15,24,46,[53][54][55]57,82,95] which focused on the gender issue. This limited number of studies that included separately male and female participants may contribute to the absence of a gender effect on 8-isoprostane concentration in EBC.…”

Use of exhaled breath condensate to investigate occupational lung diseases

“…It has been applied among hairdressers [25], ship-engine workers [26], workers exposed to welding fumes [19] and chrome-plating workers [7].…”

Biomarkers in the Exhaled Breath Condensate of Healthy Adults: Mapping the Path Towards Reference Values

“…• Inhalation of pneumotoxic substances: Only a limited number of studies has assessed the potential role of EBC as a means for determining exposure to inhaled pneumotoxic substances in the work environment (ship-engine and chrome plating workers, volunteers exposed to pig house dust) [143,144] whereas no study has yet described the effect of passive smoke inhalation on EBC markers in adults [145].…”