Quebrangulo, nestled in the state of Alagoas, Brazil, occupies a geographically significant position within the Northeast region. Located at approximately -9.3189° latitude and -36.4711° longitude, the city’s terrain is characterized by undulating hills and valleys, typical of the Seridó region. Its elevation, while modest, contributes to localized microclimates and influences air circulation patterns. Quebrangulo sits within a transitional zone between the Agreste and Sertão ecosystems, impacting its surrounding landscape. To the west, the landscape gradually shifts towards the drier, more arid conditions of the Sertão, while to the east, the influence of the Atlantic coast brings slightly higher humidity and rainfall. The Rio Una, a vital waterway for Alagoas, flows relatively close to Quebrangulo, though not directly through the urban core, influencing regional water resources and potentially impacting downwind air quality from agricultural practices in the river basin. The urban–rural gradient around Quebrangulo is relatively sharp; the city is surrounded by agricultural land, primarily focused on sugarcane cultivation and livestock farming. This proximity to agricultural zones introduces potential sources of particulate matter and volatile organic compounds (VOCs) into the local atmosphere, particularly during harvest seasons. While Quebrangulo isn't situated within a major industrial belt, the regional economy relies on processing agricultural products, which can contribute to localized air pollution. The city’s relatively small size (population 11,248) means that urban emissions are less significant than those potentially arising from surrounding agricultural activities and regional transport corridors.

Quebrangulo’s tropical climate dictates a distinct wet and dry season pattern, profoundly influencing its air quality. The dry season, typically spanning from September to April, is characterized by reduced rainfall and increased sunshine hours. This period often sees a build-up of pollutants due to decreased atmospheric cleansing through precipitation. Stagnant air masses, particularly during the months of October to February, can exacerbate this issue, leading to a concentration of particulate matter and gaseous pollutants originating from agricultural burning practices common in the region. The dry winds, while sometimes dispersing pollutants, can also carry dust and smoke from distant agricultural fires, significantly impacting air quality. The wet season, from May to August, brings frequent rainfall and higher humidity, naturally scrubbing the atmosphere and reducing pollutant concentrations. However, the onset of the wet season can be preceded by periods of fog, especially in the mornings, which can trap pollutants near the ground. Sensitive groups, including children, the elderly, and individuals with respiratory conditions, should exercise caution during the dry season, particularly during periods of agricultural burning. Limiting outdoor exertion during peak hours and monitoring local air quality reports (when available) is advisable. The increased humidity during the wet season can sometimes trigger mold growth, which can affect indoor air quality. Maintaining good ventilation and addressing any moisture issues within homes is crucial. While the wet season generally offers improved air quality, the potential for fog and associated pollutant trapping requires continued vigilance.