A study on road traffic noise exposure and prevalence of insomnia

The potential of the nocturnal traffic noise to affect the quality and the quantity of sleep makes it a serious threat to public health. The present study is an attempt to provide insights into the ways through which nocturnal traffic noise causes insomnia. A total of 4525 respondents participated in the study. Modelled nocturnal noise levels were used, and the assessment of insomnia-related symptoms was done using the Jenkins sleep problem scale. A directed acyclic graph was used to obtain the minimum set of confounders that need to be adjusted for obtaining unbiased estimates. DASS-21 item scale was used to evaluate the mental health of respondents. The study reported significant associations between traffic noise exposure and all insomnia-related symptoms. For the total study population, the highest risk occurred for difficulty in falling asleep symptom (OR = 1.45; 95% CI = 1.01 - 2.07). Based on the sensitivity analysis, respondents with bedrooms facing the road were found to have higher risks as compared to the overall sample with the highest risks occurring for difficulty in maintaining the sleep symptom (OR = 1.65; 95% CI = 1.08 - 2.51). Severity levels of mental disorders showed an increasing trend with the increasing noise levels. Females were found to have a higher risk as compared to males (OR = 1.75; 95% CI = 1.14 - 2.69). No significant association was found between traffic noise exposure and sleep medication usage. Future research on large populations can help in minimizing the impacts of nocturnal noise on public health.