Biomarkers of endothelial activation and thrombosis in tunnel construction workers exposed to airborne contaminants.

Objectives: The aims were to study biomarkers of systemic inflammation, platelet/endothelial activation and thrombosis in tunnel construction workers (TCW).

Methods: Biomarkers and blood fatty acids were measured in blood of 90 TCW and 50 referents before (baseline) and towards the end (follow-up) of a 12 days work period. They had been absent from work for 9 days at baseline. Air samples were collected by personal sampling.

Results: Personal thoracic air samples showed geometric mean (GM) particulate matter and α-quartz concentrations of 604 and 74 µg/m, respectively. The arithmetic mean (AM) concentration of elemental carbon was 51 µg/m. The GM (and 95% confidence interval) concentration of the pro-inflammatory cytokine TNF-α decreased from 2.2 (2.0-2.4) at baseline to 2.0 pg/mL (1.8-2.2) (p = 0.02) at follow-up among the TCW. Also the platelet activation biomarkers P-selectin and CD40L decreased significantly [25.4 (24.1-26.6) to 24.4 (22.9-26.0)] ng/mL, p = 0.04 and 125 (114-137) to 105 (96-115) pg/mL, p < 0.001, respectively. ICAM-1 concentrations increased from 249 (238-260) to 254 (243-266) ng/mL (p = 0.02). No significant alterations were observed among the referents when assessed by paired sample t test. Unbeneficial alterations in blood fatty acid composition were observed between baseline and follow-up, mainly among referents.

Conclusions: TCW had slightly reduced systemic inflammation and platelet activation although highly exposed to particulate matter, α-quarz and diesel exhaust, which might be due to increased physical activity during the exposure period. The slightly increased ICAM-1 may indicate monocyte recruitment to the lungs. The diet was substantially altered towards a less beneficial fatty acid profile.