Street Children Exposure to Ambient Fine Particulate Matter (PM 2.5 ) and Environmental Noise: An Exposure Assessment and Health Risk Analysis Study

Street children, particularly those aged 3–8 years, may exhibit a pronounced vulnerability to environmental risk factors. This study investigated the exposure of street children to ambient fine particulate matter (PM _2.5 ) and environmental noise at 30 major intersections in Tehran city, Iran. PM _2.5 concentrations, noise levels, temperature, humidity, and traffic conditions were measured. Health risks were also assessed using hazard quotients (HQ) for different age groups, focusing on non-carcinogenic risks and psychological effects. PM _2.5 concentrations exceeded 15 µg/m ³ at all intersections except one, with levels surpassing 40 µg/m ³ at key intersections. Noise levels consistently exceeded 70 dB, with some intersections surpassing 80 dB, far above the WHO guidelines of 53 dB. Health risk analysis revealed HQ values over 2 for children aged 3–8 years at numerous intersections, indicating significant hazards. The study emphasizes the environmental risks faced by street children in Tehran, revealing that elevated concentration of PM _2.5 and noise exposure pose significant health threats. Immediate interventions, including traffic control and regulatory measures, are essential to mitigate these exposures. Enhanced understanding of these environmental risks underscores the need for urgent policy actions to protect this vulnerable population.