Effects of mixtures containing chlordecone and a dechlorinated by-product on hydra regeneration capacity: use of experimental design to evaluate the toxicity risk associated with remediation programs in long-lasting polluted areas

Chlordecone (CLD), an obsolete insecticide, used in the French West Indies between 1972 and 1993, is persistent in the environment but can be dechlorinated either chemically or under the action of microorganisms. Therefore, if soil remediation programs based on these processes are implemented in areas still contaminated today, those will see their concentrations of dechlorinated derivatives increase and these compounds will be also found in freshwater by streaming, leaching and erosion processes. The purpose of the present study was to evaluate, at environmental concentrations, the toxic effects of mixtures of chlordecone and a three-chlorine substituted byproduct. A hydra clone, which has been confirmed to be Hydra vulgaris Pallas, 1766 has been retained for bioassays where the toxicity has been evaluated by regeneration capacity during exposure. Exposure to mixtures is complex to investigate by classical methods, therefore, an experimental design associated to a mathematical model has been used to predict the effects of all the mixtures and to detect the toxic influence of each compound. The predictive model is discussed regarding the stochastic “endocrine disruptor effect” of CLD. At probable environmental concentrations of the compounds in the mixture, results show that impairment of regeneration capacity is explained mostly by the presence of CLD in the mixtures and support the implementation of remediation programs aimed at dechlorination of this persistent organochlorine pesticide.

Understanding the Endocrine Disruptor and Determination of Bisphenol A by Functional Cu-BTABB-MOF/rGO Composite as Facile Rapid Electrochemical Sensor: An Experimental and DFT Investigation

A pioneering CuBTABB-MOF/rGO composite customized electrode is fabricated and utilized as a sensor towards identifying Bisphenol A (BPA) ina phosphate buffer solution of pH7.0. Composite is characterized by FTIR, Raman...

UV light irradiation combined with nitrate for degradation of bisphenol A: kinetics, transformation pathways, and acute toxicity assessment

As an endocrine disruptor, bisphenol A (BPA) is a severe threat to human health. In this study, nitrate (NO3-) photolysis with a low-pressure UV lamp (LP-UV) was employed to degrade...

Effects of Degradation of Nonylphenol in Waste Water by Strong Ionization and Its Degradation Products on Sex Differentiation in Zebrafish

Nonylphenol (NP), as a typical environmental endocrine disruptor, exists widely in the natural environment. It has a high toxicity with a low concentration. NP at the level of μg/L is enough to interfere with the sex differentiation of many aquatic organisms. The effects of degradation of NP in waste water by strong ionization (SID) and its degradation products on sex differentiation in zebrafish was studied in this paper. The NP solution of 5mg/L was degraded by SID device, and the 20d zebrafish were exposed to NP wastewater of different concentrations before and after degradation until their sexual maturity. The body length, body weight and sex differentiation ratio of zebrafish were recorded, and the sex hormone levels of zebrafish were extracted and detected. The gonadal glands of zebrafish were slices and analysed. This study found that the effects of nonylphenol on male zebrafish were much greater than that of female, and there was no significant positive correlation between toxicity and dose. In addition, the effects of 5mg/L NP wastewater degraded by SID for 60min were not significantly different from those of the control group, indicating that SID could effectively degrade NP and alleviate its biological toxicity.