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Alhandra, nestled in the state of Paraíba, Brazil, occupies a geographically significant position within the semi-arid zone of the Northeast. Located at -7.3504 latitude and -34.9284 longitude, the city’s terrain is characterized by gently undulating coastal plains, a typical feature of this region. Its elevation is relatively low, contributing to limited natural dispersion of pollutants. The city benefits from proximity to the Paraíba River, which influences local humidity and can, under certain conditions, trap pollutants. Surrounding Alhandra is a mosaic of agricultural land, primarily sugarcane and fruit plantations, alongside pockets of native *caatinga* scrubland. The urban-rural gradient is relatively sharp, with agricultural activities dominating the immediate periphery. While not a major industrial hub itself, Alhandra’s location along transport routes connecting the interior to the port of Cabedelo exposes it to emissions from passing vehicles. The coastal location means sea breezes play a role in air circulation, but these can also carry salt spray and, occasionally, pollutants from coastal industrial areas further north. The prevailing winds are generally easterly, bringing moisture from the Atlantic, but local topography can create microclimates affecting pollutant concentration. Understanding this interplay of geography and activity is crucial for assessing Alhandra’s air quality.

Alhandra experiences a distinct wet and dry season, heavily influencing its air quality. The dry season, typically from August to December, is characterized by lower humidity and increased dust and particulate matter in the air, exacerbated by agricultural activities like sugarcane harvesting and land preparation. These activities release significant amounts of PM10 and PM2.5. Wind speeds are generally lower during this period, reducing pollutant dispersion. January to July marks the wet season, bringing relief from dust but also potential for increased fungal spores and mold. Rainfall washes particulate matter from the atmosphere, temporarily improving air quality, but can also lead to localized flooding and the spread of pollutants from agricultural runoff. Temperature inversions, common during the cooler nights of the dry season, trap pollutants near the ground, worsening conditions. February and March, during peak rainfall, generally offer the best air quality for outdoor activities. Sensitive groups – children, the elderly, and those with respiratory conditions – should limit outdoor exposure during the dry season, particularly in November and December. Monitoring wind patterns and agricultural schedules is vital for predicting pollution episodes.