Search

The toxicity of endocrinologically active pharmaceuticals finasteride (FIN) and melengestrol acetate (MGA) was assessed in freshwater mussels, including acute (48 h) aqueous tests with glochidia from Lampsilis siliquoidea, sub-chronic (14 days) sediment tests with gravid female Lampsilis fasciola, and chronic (28 days) sediment tests with juvenile L. siliquoidea, and in chronic (42 days) sediment tests with the amphipod Hyalella azteca and the mayfly Hexagenia spp. Finasteride was not toxic in acute aqueous tests with L. siliquoidea glochidia (up to 23 mg/L), whereas significant toxicity to survival and burial ability was detected in chronic sediment tests with juvenile L. siliquoidea (chronic value (ChV, the geometric mean of LOEC and NOEC) = 58 mg/kg (1 mg/L)). Amphipods (survival, growth, reproduction, and sex ratio) and mayflies (growth) were similarly sensitive (ChV = 58 mg/kg (1 mg/L)). Melengestrol acetate was acutely toxic to L. siliquoidea glochidia at 4 mg/L in aqueous tests; in sediment tests, mayflies were the most sensitive species, with significant growth effects observed at 37 mg/kg (0.25 mg/L) (ChV = 21 mg/kg (0.1 mg/L)). Exposure to sublethal concentrations of FIN and MGA had no effect on the (luring and filtering) behaviour of gravid L. fasciola, or the viability of their brooding glochidia. Based on the limited number of measured environmental concentrations of both chemicals, and their projected concentrations, no direct effects are expected by these compounds individually on the invertebrates tested. However, organisms are exposed to contaminant mixtures in the aquatic environment, and thus, the effects of FIN and MGA as components of these mixtures require further investigation.

The authors also gratefully acknowledge L. Geoffroy, L. Chancerelle and P. Pandard from the INERIS Institut.; International audience; To limit in vivo experiments, the use of quantitative structure-activity relationships (QSARs) is advocated by REACH regulation to predict the required fish, invertebrate, and algae EC50 for chemical registration. The aim of this work was to develop reliable QSARs in order to model both invertebrate and algae EC50 for organic solvents, regardless of the mechanism of toxic action involved. EC50 represents the concentration producing the 50 % immobilization of invertebrates or the 50 % growth inhibition of algae. The dataset was composed of 122 organic solvents chemically heterogeneous which were characterized by their invertebrate and/or algae EC50. These solvents were described by physico-chemical descriptors and quantum theoretical parameters calculated via density functional theory. QSAR models were developed by multiple linear regression using the ordinary least squares method and descriptor selection was performed by the Kubinyi function. Invertebrate EC50 was well-described with LogP, dielectric constant, surface tension, and minimal atomic Mulliken charges while algae EC50 of organic solvents (except amines) was predicted with LogP and LUMO energy. To evaluate robustness and predictive performance of the QSARs developed, several strategies have been used to select solvent training sets (random, EC50-based selection and a space-filling design) and both internal and external validations were performed.

The thermal decomposition of Fenitrothion [phosphorothioic acid O,O-diethyl O-(3-methyl-4-nitrophenyl) ester] was investigated. Results obtained by different scale calorimetric techniques show that the thermal decomposition of Fenitrothion involves two main steps. Intermediate and final thermal degradation products formed during isothermal and adiabatic thermal decomposition experiments were identified. The eco-toxicological profile of the decomposition products was assessed experimentally and compared to results obtained with a predictive software (ECOSAR). A specific index was defined to assess the change in ecotoxicity profile of decomposition products with respect to the original compound.

The spatial distribution of small pelagic fishes off the Southeastern Brazilian coastal area (22°-29°S) was investigated over six periods, from 1995 to 2010, in the context of the Program "Prospection and Assessment of the Biomass of the Sardine, Sardinella brasiliensis " in order to provide data about their pattern of distribution and biomass. A checklist of the species collected is presented herein with data on geographic position and depth of captures. Such information is intended to be a reference about the fauna that occupied the region in the period under investigation, and allow future comparisons about the resilience of the local fauna, i.e., the detection of future changes caused by environmental factors or human activities. Sampling was conducted during hydroacoustic surveys with mid water trawling plus a few purse seine operations between 10 m and 100 m depth. A total of 86 species were collected.