Polycyclic aromatic hydrocarbons (PAH) in superficial water from a tropical estuarine system: Distribution, seasonal variations, sources and ecological risk assessment.

This study aimed to evaluate the PAH distribution, sources, seasonal variations and ecological risk assessment in superficial water from the Japaratuba River, Brazil. PAH concentrations ranged from 4 to 119ngL. It was observed that the PAH total concentrations and profiles showed significant differences when comparing the dry season (summer) with the rainy season (winter). Furthermore, most of the PAH originated from pyrogenic sources in the winter, whereas a mixture of sources was observed in the summer. PAH concentration levels found in this study were considered lower than those obtained in other estuarine systems. Ecological risk assessment was determined for individual PAH, based on the risk quotient (RQ) to evaluate the risk of aquatic biota's exposure to PAH. Results suggested that the Japaratuba River has achieved a moderate degree of ecological risk for high molecular weight, showing the importance of identifying these carcinogenic and mutagenic compounds in aquatic systems.