Pilich, a small town in the Patna division of Bihar, India, sits at coordinates 25.2379°N, 85.3483°E. The town’s geography is characteristic of the Indo-Gangetic Plain – a flat, fertile alluvial landscape. Pilich’s elevation is relatively low, contributing to limited atmospheric dispersion of pollutants. The surrounding terrain is predominantly agricultural, with extensive rice paddies and wheat fields dominating the landscape. The Phalgu River, a tributary of the Ganges, flows nearby, influencing local humidity and potentially contributing to localised fog formation during cooler months. Pilich is not a major industrial hub, but regional brick kilns and small-scale agricultural processing contribute to particulate matter emissions. The urban-rural gradient is sharp; Pilich is surrounded by villages and farmland, meaning that agricultural practices like crop residue burning directly impact air quality. The town’s position within the densely populated Bihar plain means it’s susceptible to regional pollution transport from larger urban centres like Patna. Limited green cover within the town itself further exacerbates the issue, reducing the natural filtration of airborne pollutants. This combination of factors creates a challenging environment for maintaining clean air.

Pilich 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, high humidity can also foster mould growth, impacting respiratory health. October-November sees a deterioration in air quality as post-monsoon conditions prevail – stagnant air, cooler temperatures, and increased burning of agricultural residue after the harvest. This is often the most polluted period. Winter (December-February) brings temperature inversions, trapping pollutants near the ground and exacerbating smog. Fog formation is common, further reducing visibility and increasing pollutant concentrations. March-May is characterised by rising temperatures and dry winds, leading to increased dust and particulate matter. These hot, dry conditions can trigger dust storms. Sensitive groups – children, the elderly, and those with respiratory conditions – should limit outdoor activity during October-February. Avoiding peak hours and wearing masks can offer some protection. Monitoring local conditions and heeding health advisories is crucial throughout the year, but particularly during the post-monsoon and winter months.