NORAH - field study: The Effects of chronic exposure to traffic noise (aircraft, rail and road) on hypertension

Introduction: Based on the concept that noise may trigger repeatedly unavoidable autonomous physiological reactions, which each can cause an increase of blood pressure, the study examined the effects of chronic traffic noise exposure (outside) on hypertension. Methods: Study region includes areas near Frankfurt airport within the 40 dB(A) equivalent continuous sound level contours of aircraft noise for day and night-time, targeting on voluntary adults residing in the defined region. Participants performed 2 daily (morning, night) self blood pressure measurements for 21 days. Additionally they completed questionnaires with reference to current health, medications, lifestyle, and individual factors. Those with values systolic >140 and/or diastolic >90 mmHg (daily mean) and/or antihypertensive medication were classified as hypertensives. Results: Separate logistic regression models (n=844 (58.4% w; 41.6% m) were performed for all three sources (LpA,eq,18-06h aircraft, rail and road), and hypertension as outcome. All models were adjusted for age, gender and social status. Additional influencing variables were added if fitting model requirements. We found no significant increased risk for hypertension (all p-values > 0.05). Conclusions: Overall this result - no evidence for increased risk of hypertension as dichotomous outcome due to traffic noise- in our study stands in line with literature with mixed results.