Effects of diesel exposure on lung function and inflammation biomarkers from airway and peripheral blood of healthy volunteers in a chamber study

Abstract

BackgroundExposure to diesel exhaust causes inflammatory responses. Previous controlled exposure studies at a concentration of 300 μg/m3 of diesel exhaust particles mainly lasted for 1 h. We prolonged the exposure period and investigated how quickly diesel exhaust can induce respiratory and systemic effects.MethodsEighteen healthy volunteers were exposed twice to diluted diesel exhaust (PM1 ~300 μg/m3) and twice to filtered air (PM1 ~2 μg/m3) for 3 h, seated, in a chamber with a double-blind set-up. Immediately before and after exposure, we performed a medical examination, spirometry, rhinometry, nasal lavage and blood sampling. Nasal lavage and blood samples were collected again 20 h post-exposure. Symptom scores and peak expiratory flow (PEF) were assessed before exposure, and at 15, 75, and 135 min of exposure.ResultsSelf-rated throat irritation was higher during diesel exhaust than filtered air exposure. Clinical signs of irritation in the upper airways were also significantly more common after diesel exhaust exposure (odds ratio=3.2, p<0.01). PEF increased during filtered air, but decreased during diesel exhaust exposure, with a statistically significant difference at 75 min (+4 L/min vs. -10 L/min, p=0.005). Monocyte and total leukocyte counts in peripheral blood were higher after exposure to diesel exhaust than filtered air 20 h post-exposure, and a trend (p=0.07) towards increased serum IL-6 concentrations was also observed 20 h post-exposure.ConclusionsDiesel exhaust induced acute adverse effects such as symptoms and signs of irritation, decreased PEF, inflammatory markers in healthy volunteers. The effects were first seen at 75 min of exposure.

Controlled exposure to diesel exhaust and traffic noise – Effects on oxidative stress and activation in mononuclear blood cells

“…In the present exposure study increased counts of total leukocytes and monocytes were found at 20 h post-exposure [13]. We studied gene expression of IL8 and TNF in PBMCs at the same time point as the genotoxicity measurements.…”

“…Eighteen subjects (9 male and 9 female, non-smoking and 40-66 years) were recruited for the study as further described in the supplement and previously [13,14]. The study was performed after approval by the Regional Ethical Review Board in Sweden.…”

“…Previous observations from the same study have shown that the DE-exposure resulted in decreased lung function and increased leukocyte counts in peripheral blood [13]. In addition, PM collected in the exposure chamber was assessed for the ability to induce oxidative stress, DNA damage and inflammatory response in human whole blood ex vivo in order to simulate effects after potential translocation from the lungs to the circulation.…”

Acute effects on pulmonary function in young healthy adults exposed to traffic-related air pollution in semi-closed transport hub in Beijing

“…Acute respiratory effects of exposure to diesel exhaust have also been studied in controlled chamber studies [9][10][11][12][13][14][15]. Most studies generally did not found effects on lung function parameters in relation to short-term air pollution chamber exposure [9][10][11][12][13][14].…”

“…Acute effects on pulmonary function of exposure to traffic exhaust have been studied in controlled chamber studies [9][10][11][12][13][14][15]. However, considering the realworld exposure where mixtures of pollutants are more complex, the results of chamber studies may have some difficulties when applied to the exposure in real-world traffic micro-environment.…”