Transportation noise affects millions of people globally. This umbrella review assesses the quality of the evidence across existing systematic reviews on the association between environmental transportation noise (from roads, railways and aircraft) and child and adolescent mental health outcomes (depression, anxiety, hyperactivity/inattention, behavioural problems, and emotional symptoms). It also identifies inequality in associations for factors such as deprivation and ethnicity. Seven databases were searched from January 2015 up to January 2025. Studies were screened for inclusion independently by two reviewers. The AMSTAR2 (A MeaSurement Tool to Assess systematic Reviews 2) framework was used to critically appraise the systematic reviews. A total of eight systematic reviews and one report from grey literature were included. Each noise source (road, railway and aircraft) showed a mixture of associations with mental health outcomes. For example, reviewing the evidence available, existing systematic reviews suggest that road traffic noise has a harmful association with anxiety but no association with depression. The overall quality of the evidence varied widely, ranging from very low to moderate. Significant evidence gaps were identified on railway noise as an exposure source and the association of noise with anxiety and depression. A notable gap was the absence of meaningful subgroup analyses by socioeconomic deprivation or ethnicity, limiting understanding of potential effect inequalities and vulnerability to environmental noise exposure. The findings indicate a heterogenous evidence base, underscoring the need for more robust, longitudinal investigations using standardised exposure and outcome assessments to increase certainty of the estimates. Future research should focus on the associations of transportation noise with depression and anxiety; and should incorporate an inequality perspective to better understand the distribution of these associations and address population health disparities.
Hussain et al. (Fri,) studied this question.