High-Resolution Spatial-Temporal Mapping of Urban Noise Pollution in Chennai Using Mobile Sensing and GIS: A Ward-Level Public Health Assessment

Background: Noise pollution is a growing public health issue in urban India, contributing to cardiovascular diseases, cognitive decline, and psychological stress. Despite its serious health implications, environmental noise remains poorly monitored in Indian cities. This study focuses on mapping ambient noise exposure at the ward level in Chennai, Tamil Nadu, to identify hotspots and aid in urban noise management. Methods: A cross-sectional study was conducted across all 200 wards of Chennai. Ambient noise levels were measured using the NIOSH Sound Level Meter mobile app at three time intervals—morning, noon, and evening. For each ward, three readings per time slot were averaged. Spatial analysis and mapping were performed using QGIS, with spatial autocorrelation assessed via GeoDa. Results: Noise levels varied by time and location, with higher exposure observed in mornings and mid-days in dense residential and commercial zones. Evenings showed persistently high noise levels citywide. Wards such as Manali, Tondiarpet, and Sholinganallur consistently exceeded 85 dB, while peripheral wards remained relatively quiet. Spatial clustering revealed noise hotspots in northern and central Chennai. Conclusion: Ward-level noise mapping provides actionable data for targeted interventions. Combining mobile-based monitoring with spatial tools offers a scalable, cost-effective model for environmental noise assessment across Indian cities. DOI: https://doi.org/10.52783/jchr.v15.4.9261