Saliva Cortisol and Exposure to Aircraft Noise in Six European Countries

Background: Several studies show an association between exposure to aircraft or road traffic noise and cardiovascular effects, which may be mediated by a noise-induced release of stress hormones. Objective: Our objective was to assess saliva cortisol concentration in relation to exposure to aircraft noise. Method: A multicenter cross-sectional study, HYENA (Hypertension and Exposure to Noise near Airports), comprising 4,861 persons was carried out in six European countries. In a subgroup of 439 study participants, selected to enhance the contrast in exposure to aircraft noise, saliva cortisol was assessed three times (morning, lunch, and evening) during 1 day. Results: We observed an elevation of 6.07 nmol/L [95% confidence interval (CI), 2.32-9.81 nmol/L] in morning saliva cortisol level in women exposed to aircraft noise at an average 24-hr sound level ($L_{Acq,24h}$) > 60 dB, compared with women exposed to$L_{Acq,24h}$≤ 50 dB, corresponding to an increase of 34%. Employment status appeared to modify the response. We found no association between noise exposure and saliva cortisol levels in men. Conclusions: Our results suggest that exposure to aircraft noise increases morning saliva cortisol levels in women, which could be of relevance for noise-related cardiovascular effects.