Pharkia, a small city nestled within the state of Bihar, India, occupies a relatively flat alluvial plain at approximately 25.9384°N, 87.4034°E. Its location in the Gangetic plains significantly influences its air quality. The surrounding landscape is predominantly agricultural, characterized by intensive farming of rice, wheat, and sugarcane. This agricultural activity, while vital to the local economy, contributes to particulate matter pollution through crop residue burning, particularly after the harvest seasons. The city’s proximity to the Burhi Gandak river, a tributary of the Ganges, introduces humidity and can contribute to localized fog formation, trapping pollutants. Pharkia isn’t a major industrial hub, but regional brick kilns and small-scale industries in nearby areas contribute to emissions. The urban-rural gradient is fairly sharp; Pharkia itself is a concentrated settlement, but quickly transitions to rural farmland. This means pollutants generated within the city have limited dispersion, and are easily impacted by regional agricultural practices. The flat terrain hinders natural ventilation, exacerbating pollution build-up. Dust from unpaved roads and construction activities further degrades air quality, especially during the drier months. The city’s position within the Indo-Gangetic Plain, a known hotspot for air pollution, makes it particularly vulnerable to regional pollution transport.

Pharkia experiences a distinct seasonal air quality pattern dictated by the monsoon and post-monsoon periods. The monsoon season (June-September) generally brings temporary relief, as rainfall washes away particulate matter and increased humidity suppresses dust. However, stagnant air during periods of reduced rainfall can still lead to localized pollution. October-November sees a significant deterioration in air quality. The post-monsoon period coincides with crop residue burning, a major source of PM2.5 and PM10. Cooler temperatures and calm winds create temperature inversions, trapping pollutants near the ground. December-February are typically the worst months, with consistently poor air quality due to continued burning, winter fog, and reduced atmospheric mixing. March-May brings increasing temperatures and drier conditions, leading to dust storms and increased particulate matter. While the heat can disperse some pollutants, it also exacerbates ozone formation. Sensitive groups – children, the elderly, and those with respiratory conditions – should limit outdoor activity during October-February. Avoiding peak burning times and using N95 masks when outdoors are recommended. Monitoring local conditions and staying indoors on heavily polluted days is crucial for protecting health.