Measurement of Traffic-Related Air Pollution in Peshawar, Pakistan - A Pilot Study

Abstract

This pilot study measured Traffic-Related Air Pollution (TRAP) and calculated the corresponding Air Quality Index (AQI) in Peshawar. Using Libelium wireless sensors, the research measured outdoor TRAP and monitored indoor air quality for 48 days. The maximum outdoors daily mean concentration was 47 µg m⁻³ for PM₁, 90 µg m⁻³ for PM_2.5, 356 µg m⁻³ for PM₁₀, 258 ppb for SO₂, and 219 ppb for NO₂, respectively. This corresponds to PM_2.5 AQI of 158 (Unhealthy), PM₁₀ AQI of 148 (Unhealthy for Sensitive Groups; USG), SO₂ AQI of 181 (Unhealthy), and NO₂ AQI of 123 (USG). The maximum daily average concentration for the indoor condition was 31 µg m⁻³ for PM₁, 49 µg m⁻³ for PM_2.5, 78 µg m⁻³ for PM₁₀, 465 ppb for SO₂, and 247 ppb for NO₂, respectively. The corresponding AQI was 135 (USG) for PM_2.5, 62 (Moderate) for PM₁₀, 254 (Very Unhealthy) for SO₂, and 129 (USG) for NO₂. Data analysis shows that about 73% of the overall indoor AQI falls in the category of “USG”, while SO₂ was the largest contributor to overall AQI. The study concludes that indoor AQI was slightly better than outdoor AQI because of the distance and height from the outdoor location. Moreover, Pakistan’s AQI for PM_2.5 exceeds WHO’s 24-hours limit; however, it was relatively better by 23%, 65%, and 170% compared to China, India, and Bangladesh, respectively. In contrast, AQI for SO₂ and NO₂ was poor as compared to the same countries. The concentration and AQI for traffic-related air pollutants remain unhealthy and sometimes becomes hazardous, which means the sensitive groups are at greater risk.