Aromatic hydrocarbons in mangrove areas in Tabasco: Preliminary studies

Abstract

This preliminary study evaluates the presence of total petroleum hydrocarbons (TPH) and aromatic fractions (HA) in mangrove soils in the municipality of Jalpa de Méndez, Tabasco, near the Laguna Mecoacán, Natural Protected Area, a strategic area due to its proximity to the Dos Bocas maritime terminal and the Olmeca refinery. Seventeen sites with varying degrees of disturbance were analyzed, also measuring pH and electrical conductivity (EC) parameters as geochemical indicators of environmental status. The results showed that, although TPH and HA levels do not exceed the limits established by NOM-138-SEMARNAT-SSA1- 2012, several samples exceed ecological risk thresholds 500 mg/kg for HA), which could represent a danger to biota and local communities. A positive correlation was identified between TPH and HA (R2 = 0.8846 when urban areas were excluded), and a trend toward decreasing pH and increasing EC was observed in soils with greater contamination, suggesting hydrocarbon-induced salinization and acidification processes. The observed spatial variability reflects the ecological complexity of the system and suggests cumulative impacts of petroleum activities. Continued monitoring, evaluation of bioindicators, and consideration of ecological restoration strategies are recommended to mitigate the effects on these vulnerable ecosystems.