Assessment of PM2.5 and PM10 Exposure and Health Risks: A Study of Pedestrian and Two-Wheeler Transport During Peak-Traffic in Imphal, Manipur

This study looks at the levels of PM _2.5 and PM ₁₀ people are exposed to during busy traffic times when walking, riding two-wheelers, and at a fixed-site. Hourly average data was used to compare the amounts of particulate matter with the WHO air quality guidelines, which recommend limits of 15 µg/m³ for PM _2.5 and 45 µg/m³ for PM ₁₀ , respectively. The results showed that particulate matter levels changed a lot between morning and evening peak hours, with higher levels on weekdays compared to weekends. Two-wheeler users had the highest exposure, with average levels of 79.72±41.87 µg/m³ for PM _2.5 and 131.48±69.32 µg/m³ for PM ₁₀ in the morning, and 109.15±38.63 µg/m³ for PM _2.5 and 181.25±64.22 µg/m³ for PM ₁₀ in the evening, mostly due to traffic emissions and the design of the vehicles. In comparison, walking and fixed-site had more steady levels of particulate matter. All transport modes went over the WHO guidelines, with two-wheeler users facing the highest exposure with exceedance factor of 6.33 and 3.50 for PM _2.5 and PM ₁₀ , respectively. Whereas, exceedance factors of walking were 4.10 and 2.27 and for fixed-site were 4.10 and 2.32 for PM _2.5 and PM ₁₀ , respectively. The health risks from long-term exposure to these high levels are discussed, stressing the need for actions and strategies to improve air quality in cities.