Toxicities of Four Parabens and Their Mixtures to Daphnia magna and Aliivibrio fischeri

The objective of this study was to determine toxicities of four parabens (methyl paraben, MP; ethyl paraben, EP; n-propyl paraben, PP; and n-butyl paraben; BP) and their mixtures to two aquatic microorganisms, Daphnia magna and Aliivibrio fischeri. Parabens are one of the widely used preservatives for personal care products, such as cosmetics, pharmaceuticals and food also. First, each paraben was treated to D. magna to measure the toxicity levels as LC₂₀ and LC₅₀. The results showed their value of MP (25.2 mg/L, 73.4 mg/L), EP (18.4 mg/L, 43.7 mg/L), PP (10.4 mg/L, 21.1 mg/L) and BP (3.3 mg/L, 11.2 mg/L). Then, each of the parabens was treated to A. fischeri and calculated their EC₂₀ and EC₅₀ by bioluminescence inhibition test. The results showed the values of MP (2.93 mg/L, 16.8 mg/L), EP (1.18 mg/L, 6.74 mg/L), PP (0.51 mg/L, 5.85 mg/L) and BP (0.21 mg/L, 2.34 mg/L). These four parabens belong to the group classified as being ‘harmful to aquatic organisms’ (above 10 mg/L, below 100 mg/L). After measuring the toxicity, EC₂₀ values of two or more parabens were tested in order to investigate their toxicity. A total of ten combinations of four parabens were tested. As a result, the bioluminescence inhibition test of A. fischeri showed that the toxicity of mixture parabens was stronger than that of a single compound and combinations of three parabens showed the highest bioluminescence inhibition. These results showed that independent toxicity of paraben was maintained. Therefore, it can be predictable that the toxicity of paraben is getting stronger by the addition of other parabens.

Toxicities of Four Parabens and Their Mixtures to Daphnia magna and Aliivibrio fischeri

The objective of this study was to determine toxicities of four parabens (methyl paraben, MP; ethyl paraben, EP; n-propyl paraben, PP; and n-butyl paraben; BP) and their mixtures to two aquatic microorganisms, Daphnia magna and Aliivibrio fischeri. Parabens are one of the widely used preservatives for personal care products, such as cosmetics, pharmaceuticals and food also. First, each paraben was treated to D. magna to measure the toxicity levels as LC₂₀ and LC₅₀. The results showed their value of MP (25.2 mg/L, 73.4 mg/L), EP (18.4 mg/L, 43.7 mg/L), PP (10.4 mg/L, 21.1 mg/L) and BP (3.3 mg/L, 11.2 mg/L). Then, each of the parabens was treated to A. fischeri and calculated their EC₂₀ and EC₅₀ by bioluminescence inhibition test. The results showed the values of MP (2.93 mg/L, 16.8 mg/L), EP (1.18 mg/L, 6.74 mg/L), PP (0.51 mg/L, 5.85 mg/L) and BP (0.21 mg/L, 2.34 mg/L). These four parabens belong to the group classified as being ‘harmful to aquatic organisms’ (above 10 mg/L, below 100 mg/L). After measuring the toxicity, EC₂₀ values of two or more parabens were tested in order to investigate their toxicity. A total of ten combinations of four parabens were tested. As a result, the bioluminescence inhibition test of A. fischeri showed that the toxicity of mixture parabens was stronger than that of a single compound and combinations of three parabens showed the highest bioluminescence inhibition. These results showed that independent toxicity of paraben was maintained. Therefore, it can be predictable that the toxicity of paraben is getting stronger by the addition of other parabens.

Evaluation of eugenol toxicity in bioassays with test-organisms / Avaliação da toxicidade do eugenol em bioensaios com organismos-teste

ABSTRACT: Fish in both natural and farming conditions are exposed to stress of capture, handling, transport or treatment that provoke low zootechnical performance. Anesthetics like eugenol obtained from clove oil have been used strategically not only in freshwater but also in marine and estuarine fish in order to reduce the stress. Apart from the eugenol indication as anesthetic and its low toxicity for animals, its environment action is not clear. Bioassays or ecotoxicity tests with indicator organisms are used to evaluate the mode of action of the pollutants in the environment. The aim of this study was to test the acute toxicity of eugenol using the microcrustacean Daphnia magna and the bacterium Aliivibrio fischeri, and also its chronic toxicity for the algae Desmodesmus subspicatus. Eugenol in the concentrations of 50, 75 and 100mg L-1 were toxic to tested indicator organisms.

RESUMO: Os peixes, seja em ambiente natural ou em piscicultura, sofrem efeito do estresse na captura, manejo, transporte ou tratamentos que provocam baixo desempenho zootécnico. Anestésicos, como o eugenol, obtido a partir do óleo de cravo, tem sido usado estrategicamente não só em peixes de água doce, mas também em peixes marinhos e estuarinos para reduzir o estresse. Apesar da indicação de eugenol como anestésico em peixes e da sua baixa toxicidade para estes animais, não se tem clareza da sua ação sobre o ambiente. Bioensaios ou testes de ecotoxicidade com organismos indicadores são usados em para avaliar o modo de ação de poluentes no ambiente. O objetivo deste estudo foi testar a toxicidade aguda do eugenol utilizando o microcrustáceo Daphnia magna e a bactéria Aliivibrio fischeri e sua toxicidade crônica para alga Desmodesmus subspicatus. O eugenol, nas concentrações de 50, 75 e 100mg L-1, foi tóxico para organismos indicadores testados.