Cenotes are naturally occurring flooded caves that are frequent in Mexico's Yucatan Peninsula; they result from the collapse of limestone bedrock into the regional groundwater table. Cenotes in Quintana Roo are important ecological and economic hot spots but are susceptible to anthropogenic pollution. In this study, we collected water samples from 11 cenotes over multiple years to evaluate polycyclic aromatic hydrocarbon (PAH) concentrations and patterns as associated with tourist traffic. The primary PAHs detected in samples included fluoranthene, anthracene, phenanthrene and naphthalene, with total PAH concentrations increasing almost fivefold for cenotes sampled from 2016 to 2017. This is compared to only a 7% increase in tourist traffic during these years. Multivariate statistical analysis of the PAH concentration data suggests that diesel, gasoline and asphalt are the most likely pollution sources and that they are associated with periods of increased tourist traffic.
Keywords: Cenotes contamination; Mexican Caribbean contamination; Polycyclic aromatic hydrocarbons; Principal component analysis.