Exposure to Diesel Exhaust and Plasma Cortisol Response: A Randomized Double-Blind Crossover Study

摘要

Traffic-related air pollution (TRAP) is associated with a varietyof adverse health effects. Although a central role has been proposed for oxidative stress, elucidating underlying mechanismsremains an area of active investigation. Experimental work hasdemonstrated that glucocorticoid stress hormones are potentialmediators of pulmonary and systemic pollutant effects of bothparticulate and gaseous pollutants (Thomson 2019), but directevidence of TRAP-dependent stress axis activation is lacking.Moreover, although oxidative stress is a regulator of glucocorticoid signaling (Okamoto et al. 1999), involvement in pollutantinduced stress axis activation is unknown. In population studies,nitrogen dioxide was associated with a flattened salivary cortisolprofile in adolescents (Wing et al. 2018) and higher awakeningcortisol and flattened profile in 45 to 85-y-old adults (Hajat et al.2019), suggesting potential TRAP-related impacts. The presentstudy evaluated whether short-term exposure to diesel exhaustincreases plasma cortisol levels and considered effect modification by sex, asthma status, antioxidant gene variants, and antioxidant treatment.