Tenosique, nestled in the southeastern Mexican state of Tabasco, occupies a crucial position within the Petén-Maya Biosphere Reserve, a landscape dominated by tropical rainforest. Situated at coordinates 17.4756, -91.4225, the city’s terrain is largely flat, characteristic of the coastal plains of the Gulf of Mexico, with an elevation hovering around 10 meters. The San Pedro and Candelaria Rivers define its eastern and western boundaries respectively, influencing local humidity and potentially contributing to localised pollutant dispersion. Tenosique functions as a vital transit point, connecting Mexico to Guatemala and Belize, resulting in significant truck traffic. While not heavily industrialised itself, the city serves as a logistical hub for agricultural produce – primarily bananas, oil palm, and cattle – from the surrounding rural areas. This agricultural activity introduces potential sources of particulate matter from land clearing and fertiliser use. The urban-rural gradient is sharp; dense settlement quickly gives way to expansive rainforest, impacting wind patterns and pollutant dilution. The proximity to the rainforest, while ecologically valuable, can also trap pollutants during periods of atmospheric stability, exacerbating air quality concerns. The city’s location within a humid tropical climate further complicates air quality management, fostering the formation of secondary pollutants.

Tenosique experiences a pronounced wet and dry season, dictating the annual air quality narrative. The dry season, typically from February to May, sees a peak in particulate matter pollution. Reduced rainfall means less atmospheric cleansing, and increased dust from unpaved roads and agricultural activities becomes more prevalent. Temperature inversions, common during calmer dry season mornings, trap pollutants near ground level. Conversely, the wet season (June to November) generally brings improved air quality. Frequent, heavy rainfall effectively washes pollutants from the atmosphere. However, increased humidity can also promote the formation of ground-level ozone, particularly during periods of intense sunlight following rainfall. December and January offer a transitional period with moderate conditions. Sensitive groups – children, the elderly, and those with respiratory conditions – should be particularly cautious during the dry season, limiting strenuous outdoor activity. The months of June through September, while wetter, require vigilance regarding potential ozone formation. Monitoring wind direction is crucial; winds from agricultural areas can carry higher concentrations of particulate matter. Avoiding peak traffic hours can also minimise exposure to vehicle emissions.