Nova Timboteua, nestled within the state of Pará in Brazil, occupies a strategically important position within the Amazon biome. Located at approximately -1.2058° latitude and -47.3858° longitude, the city’s geography is dominated by the low-lying Amazonian plain, characterized by gently undulating terrain and extensive floodplains. The Tapajós River, a major tributary of the Amazon, flows nearby, significantly influencing the local climate and hydrology. The surrounding landscape is a mosaic of dense tropical rainforest, interspersed with areas of cleared land for agriculture, primarily cattle ranching and soybean cultivation – a growing trend in the region. This agricultural activity, coupled with occasional logging operations, contributes to localized air quality concerns. The urban–rural gradient transitions rapidly from the city center to the surrounding rainforest, creating a unique juxtaposition of urban development and pristine natural environment. Elevation is minimal, rarely exceeding 50 meters above sea level, which can exacerbate the effects of temperature inversions, trapping pollutants closer to the ground. The city’s regional position, relatively isolated within Pará, means it’s less influenced by large-scale industrial belts found further east, but it is susceptible to transboundary pollution events originating from deforestation fires in the wider Amazon basin. The humid, equatorial climate, with high rainfall and temperatures, also impacts pollutant dispersion, often leading to stagnant air conditions during drier periods.

Nova Timboteua experiences a tropical climate with distinct wet and dry seasons, profoundly impacting its air quality profile. The wet season, typically spanning from November to May, brings consistent rainfall and high humidity, generally leading to improved air quality as precipitation washes away particulate matter and increased moisture facilitates pollutant dispersion. However, periods of intense rainfall can also mobilize soil particles, temporarily increasing dust levels. The dry season, from June to October, presents a more complex scenario. Reduced rainfall and lower humidity create conditions conducive to the accumulation of pollutants. The most significant concern during this period is the prevalence of smoke from agricultural burning, a common practice for land clearing and crop residue removal. This practice, often unregulated, releases substantial amounts of particulate matter and gaseous pollutants into the atmosphere. Temperature inversions, more frequent during the dry season due to calmer winds and cooler nighttime temperatures, trap pollutants near the surface, worsening air quality. Fog, occasionally occurring during the transition months, can also exacerbate the problem by reducing visibility and trapping pollutants. 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 activity during peak smoke events and utilizing air filtration systems indoors are recommended. The months of August and September often experience the highest concentrations of smoke-related pollutants.