Sulleru, nestled in the Alluri Sitharama Raju district of Andhra Pradesh, India (18.5333° N, 83.2167° E), occupies a geographically significant position within the Eastern Ghats. The town’s terrain is characterized by undulating hills and valleys, a typical feature of this region, with an average elevation of approximately 500 meters above sea level. This elevation, while not extreme, contributes to localized air circulation patterns. Sulleru is surrounded by a mosaic of landscapes: dense tropical forests to the west and north, transitioning into agricultural plains towards the east and south. The Gosthani River flows nearby, providing a crucial water source and influencing local humidity levels, which can impact pollutant dispersion. The region’s economy is a blend of agriculture (primarily rice and pulses) and limited mining activities, particularly bauxite, which, while not directly within Sulleru itself, can contribute to regional dust pollution carried by prevailing winds. The urban–rural gradient is relatively sharp; Sulleru represents a small, localized urban center surrounded by predominantly rural communities. This proximity to agricultural lands means seasonal burning of crop residue can impact air quality. The town’s location within a rain shadow area of the Eastern Ghats, coupled with the topography, can sometimes lead to stagnant air conditions, particularly during drier periods, hindering the natural dispersal of pollutants. The surrounding forests, while generally beneficial for air quality, can also release biogenic volatile organic compounds (BVOCs) that react with other pollutants.

Sulleru’s air quality experiences a distinct seasonal cycle dictated by the region’s tropical climate and monsoon patterns. The pre-monsoon season (March-May) typically witnesses the poorest air quality. High temperatures and low humidity create stable atmospheric conditions, often leading to temperature inversions where cooler air is trapped below warmer air, preventing vertical mixing and concentrating pollutants near the ground. Agricultural burning, a common practice to clear fields for the next planting season, significantly exacerbates this issue, releasing particulate matter and other harmful gases. The monsoon season (June-September) brings relief, with increased rainfall and strong winds that effectively flush out pollutants. Humidity levels rise, reducing the concentration of particulate matter. October and November mark a transitional period, with gradually decreasing rainfall and increasing temperatures, potentially leading to a slight deterioration in air quality. Winter months (December-February) are generally the most favorable for outdoor activities. Cooler temperatures and occasional wind gusts help disperse pollutants, although fog, particularly in the early mornings, can temporarily trap pollutants close to the ground. Sensitive groups, including children, the elderly, and individuals with respiratory conditions, should exercise caution during the pre-monsoon season and on foggy winter mornings. Prolonged exposure to agricultural smoke should be avoided, and protective measures like wearing masks are advisable during periods of elevated pollution. Maintaining indoor air quality through ventilation and air purifiers can also be beneficial.