Sompeta, a town in the Srikakulam district of Andhra Pradesh, India, is situated at approximately 18.93°N latitude and 84.60°E longitude. The terrain is largely coastal plain, gently sloping towards the Bay of Bengal, with an elevation averaging around 25 meters. This low-lying geography contributes to limited natural dispersion of pollutants. The town’s location is heavily influenced by its proximity to the East Godavari and Vamsadhara river deltas, creating a humid subtropical climate. Surrounding Sompeta is a mix of agricultural land, primarily paddy fields, and increasingly, industrial development focused on shrimp aquaculture and processing. This industrial activity, particularly the shrimp farms, is a significant factor in local air quality. The urban-rural gradient is relatively sharp; Sompeta itself is a concentrated settlement, quickly transitioning to rural agricultural landscapes. The coastal location means the town is susceptible to sea breezes, which can both dilute and transport pollutants depending on prevailing wind directions. The regional position, close to the Odisha border, also means it can be affected by industrial emissions from neighboring states. The flat terrain and limited topographical features hinder the flushing out of stagnant air masses, exacerbating pollution episodes.

Sompeta experiences a distinct wet and dry season pattern. The dry season, from November to May, sees consistently higher pollution levels. Lower humidity and stable atmospheric conditions during these months promote temperature inversions, trapping pollutants near the ground. January and February are typically the worst months, with minimal rainfall to cleanse the air. The monsoon season, arriving in June and lasting until October, brings significant relief. Heavy rainfall effectively washes away particulate matter, and increased wind speeds aid dispersion. However, even during the monsoon, localised pollution from shrimp processing plants and vehicular traffic can persist. Post-monsoon, in November, a gradual build-up of pollutants begins as the atmosphere stabilises. Fog formation during cooler mornings in the dry season can further worsen visibility and exacerbate respiratory issues. Sensitive groups – children, the elderly, and those with pre-existing respiratory conditions – should limit outdoor activity during the dry season, particularly in the early mornings and evenings. During the monsoon, while overall air quality improves, caution is advised near industrial areas due to potential runoff and localised emissions. Maintaining good ventilation indoors is crucial year-round.