The detoxifying effect of Polygonum equisetiforme extracts against dichlorvos (DDVP)-induced oxidative stress and neurotoxicity in the commercial clam Ruditapes decussatus

Environmental Science and Pollution Research - Effects of Polygonum equisetiforme extracts against dichlorvos were investigated in the commercial clam Ruditapes decussatus. The toxicity of this...     

Acute toxicity of polybrominated diphenyl ethers (PBDEs) for turbot (<Emphasis Type="Italic">Psetta maxima</Emphasis>) early life stages (ELS)

Background, aim and scope  

The environmental presence of polybrominated diphenyl ethers (PBDEs), among which BDE-47 and BDE-99 are particularly abundant, makes toxicity data necessary to assess the hazard risk posed by PBDE to aquatic organisms. This study examines the effects of BDE-47 and BDE-99 on embryo-larval stages of the marine flatfish turbot.     

Ecological risk assessment of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in marine environment using Isochrysis galbana, Paracentrotus lividus, Siriella armata and Psetta maxima

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are anthropogenic substances classified as persistent bioaccumulative compounds and are found in various environmental compartments throughout the world, from industrialized regions to remote zones far from areas of production. In this study, we assessed the effects of PFOA and PFOS on early life stages of marine test species belonging to three different trophic levels: one microalga (Isochrysis galbana), a primary consumer (Paracentrotus lividus) and two secondary consumers (Siriella armata and Psetta maxima). Acute EC(50) values for PFOS were 0.11 mg L(-1) in P. maxima, 6.9 mg L(-1) in S. armata, 20 mg L(-1) in P. lividus and 37.5 mg L(-1) in I. galbana. In the case of PFOA, the toxicity was lower but the ranking was the same; 11.9 mg L(-1) in P. maxima, 15.5 mg L(-1) in S. armata, 110 mg L(-1) in P. lividus and 163.6 mg L(-1) in I. galbana. The Predicted No Effect Concentration (PNEC) for PFOS and PFOA in marine water derived from these acute toxicity values are 1.1 μg L(-1) for PFOS and 119 μg L(-1) for PFOA. This study established a baseline dataset of toxicity of PFOS and PFOA on saltwater organisms. The data obtained suggest that PFOA pose a minor risk to these organisms through direct exposure. In the perspective of risk assessment, early life stage (ELS) endpoints provide rapid, cost-effective and ecologically relevant information, and links should be sought between these short-term tests and effects of long-term exposures in more realistic scenarios.     

Two leaks detection in viscoelastic pipeline systems by means of transient

This paper presents a technique for detecting and locating leaks in a single viscoelastic pipe, by means of transient analysis. The system studied is a reservoir-pipe-valve structure. The viscoelastic behavior of the pipe wall material is modeled by a generalized KelvinVoigt model. To determine the leak location, the mathematical formulation has been solved by the method of characteristics. The approach by the method of characteristics is often chosen because it is based on the concept of acoustic wave propagation which is the main mechanism of all transient events considered. The presence of the two leaks in a pipe partially reflects pressure waves initiated by the sudden closure of a downstream shut-off valve. These waves affect the shape and the amplitude of the time-history-pressure. The computed results describe the influence of the presence of two leaks on pressure time-history and the effect of leaks locations and sizes on the pressure signal behavior. The effect of the pipe wall viscoelasticity on the two leaks detection and sizing is also discussed. The leaks discharges are determined by resolving two independent equations derived from literatures and based on transient analysis. The friction and leaks depths effects on two leaks locations and sizing are involved.     

Acute toxicity and teratogenicity of carbaryl (carbamates), tebufenpyrad (pyrazoles), cypermethrin and permethrin (pyrethroids) on the European sea bass (Dicentrarchus labrax L, 1758) early life stages

Environmental Science and Pollution Research - The toxicity of carbaryl, tebufenpyrad, cypermethrin and permethrin was evaluated in European sea bass Dicentrarchus labrax during the embryonic and...