Ecological risk assessment of phthalates in the urban channels of São Vicente, Brazil

Phthalate acid esters (PAEs) are a group of plasticising chemical compounds used in the plastic industry worldwide that are well known for their environmental contamination and toxicological effects as endocrine disruptors. In this work, the occurrence and preliminary ecological risk of six PAEs – namely, dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-octyl phthalate, butyl benzyl phthalate, di-n-butyl phthalate (DBP) and di(2-ethylhexyl) phthalate – were investigated, for the first time, in five urban drainage channels located along the poor nearby neighbourhoods on the outskirts of São Vicente City, São Paulo, Brazil, whose diffuse loads flow continuously to the estuarine waters of this island. Of these, three congeners, DMP (<limit of detection (LOD), 0.023 μg/l), DEP (<LOD, 0.033 μg/l) and DBP (<LOD, 0.042 μg/l), were consistently quantified using gas chromatography coupled with tandem mass spectrometry. Specifically, the DBP occurrence is a cause of environmental concern for the São Vicente estuary, because the results suggest moderate risk for algae and fishes and high ecological risk for crustaceans after acute exposure. Therefore, even at low concentrations, the occurrence of PAEs cannot be neglected in this coastal zone. In addition, the present study reinforces the need for further ecotoxicological studies (particularly with tropical marine organisms) to assess the toxicity of these bioactive compounds.