Environmental risk assessment of parabens in surface water from a Brazilian river: the case of Mogi Guaçu Basin, São Paulo State, under precipitation anomalies.

Parabens are preservatives widely used by industry since these compounds have antifungal properties, relative low cost, and stability over a wide pH range. This study aims to quantify and assess the environmental risks of methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP) in surface water from a Brazilian River, Mogi Guaçu. The State of São Paulo, including the Mogi Guaçu River region, suffered from a period of intense drought and high temperatures, which caused anomalies in river flows and water supply problems.

Photolysis of parabens using medium-pressure mercury lamps: Toxicity effects in MCF7, Balb/c 3T3 cells and Ceriodaphnia dubia.

Degradation studies of the propylparaben (PrP), butylparaben (BuP) and of the propylparaben-butylparaben mixture (PrP-BuP) in deionized water and surface river water was investigated as a function of pH and initial concentration of the reactants using a medium-pressure mercury lamp. The photolysis of parabens (concentration ranging from 5 to 30 mg L) followed apparent pseudo-first-order kinetics, with rate constants (k) in deionized water and surface river water changed from 1.80 × 10 to 3.

Ecotoxicological effects of bisphenol A and nonylphenol on the freshwater cladocerans Ceriodaphnia silvestrii and Daphnia similis.

Toxicities of bisphenol A (BPA) and nonylphenol (NP) to the neotropical freshwater cladocerans Ceriodaphnia silvestrii and Daphnia similis were studied under laboratory conditions. Acute exposures to BPA generated mean 48-h EC values of 14.44 (6.