Loading air quality context...

Parnarama, a municipality nestled within the state of Maranhão, Brazil, occupies a position in the transition zone between the Amazon rainforest and the Cerrado savanna. Located at approximately -5.6819° latitude and -43.0928° longitude, the city’s geography is characterised by a relatively flat terrain typical of the Maranhão interior. The surrounding landscape is predominantly agricultural, with extensive areas dedicated to soybean and corn cultivation, alongside cattle ranching. This agricultural activity significantly influences local air quality. Parnarama is not directly adjacent to major bodies of water, though it lies within the Parnaíba River basin, and smaller tributaries and seasonal streams crisscross the region. The urban-rural gradient is quite sharp; Parnarama itself is a relatively small urban centre, quickly giving way to expansive agricultural lands. The lack of significant industrial belts within the immediate vicinity means that agricultural practices – including the burning of vegetation for land clearing – are the primary localised source of particulate matter. The prevailing winds, influenced by the intertropical convergence zone, play a crucial role in dispersing or concentrating pollutants, particularly during the dry season. Elevation is minimal, contributing to limited natural ventilation and potential for pollutant build-up.

Parnarama experiences a distinct wet and dry season, rather than traditional four seasons. Air quality in Parnarama is most compromised during the dry season, typically from June to November. This period sees increased agricultural burning to prepare fields for planting, releasing substantial amounts of particulate matter (PM2.5 and PM10) and other pollutants. Reduced rainfall during these months also limits the natural cleansing of the atmosphere. Temperature inversions, common during the cooler nights of the dry season, trap pollutants near the ground, exacerbating air quality issues. The wet season, from December to May, brings relief as rainfall washes away pollutants and increased humidity suppresses dust. However, even during the wet season, localised pollution from vehicle emissions and small-scale burning can occur. February and March, towards the end of the wet season, generally offer the best air quality. Sensitive groups – children, the elderly, and individuals with respiratory conditions – should limit outdoor exertion during the peak of the dry season. Monitoring wind direction is crucial; smoke plumes from agricultural fires can rapidly change air quality conditions. Avoiding outdoor activity during periods of visible haze is advisable.