Fipronil is a pyrazole insecticide used to control undesirable insect populations. Due its large-scale application, there the potential for surface waters’ contamination, with toxic action non-target organisms, and consequent impacts on aquatic ecosystems. Planarians are invertebrates these insecticides. They widespread in tropical freshwaters have been proposed as good candidates assess effect...

The Microtox Acute Toxicity Test has been successfully used to measure the toxicity of metals and other pollutants at high concentrations (ppm) in selected environmental samples. However, metals and other toxicants are often found in much lower concentrations (ppb) in many municipal wastewaters and receiving waters. In order to assess the toxicity of these pollutants in these samples, a more se...

An attempt was made to evaluate chronic effect of Potassium dichromate on Daphnia magna, semi-statically. Based on the results of an acute immobilisation study (48 hour EC50), the test item concentrations of 0.03, 0.05, 0.1, 0.2 and 0.4 mg/L of Potassium dichromate was selected for the chronic investigation. During the study, physico-chemical parameters of M4 medium were recorded and maintained...

Laundry detergents, soaps and cosmetics often include fragrance compounds such as 7-acetyl1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydro naphthalene (AHTN) and 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8hexamethylcyclopenta-γ-2-benzopyran (HHCB), that are polycyclic musks (PCMs). We assessed the potential toxicological effects associated with AHTN and HHCB using Caenorhabditis elegans (C. elegans) as a model ...

Chronic lead (Pb) toxicity tests with Brachionus calyciflorus, Chironomus tentans, and Lymnaea stagnalis were performed in artificial freshwaters. The no-observable-effect concentration (NOEC), lowest-observable-effect concentration (LOEC), and calculated 20% effect concentration (EC20) for the rotifer B. calyciflorus were 194, 284, and 125 microg dissolved Pb/L, respectively. The midge C. tent...

Pomacea lineata, an extremely ubiquitous snail and pest to rice farmers throughout Asia, holds promise as a valuable resource for monitoring water quality in northeast Brazil. In this paper, we present data demonstrating the rate of weight gain in P. lineata neonates as a consistent measure of the stress imposed by sublethal concentrations of the herbicides Paraquat and Round-up. Our secondary ...

This study was designed to investigate the effect of two surfactants, dodecyl benzyl sulfonate (DBS), sodium dodecyl sulfate (SDS), and of a domestic detergent (Y) on the AChE activity of the crustacean cladoceran Daphnia magna. All the chemicals significantly inhibit the activity of the enzyme, both in vitro and in vivo conditions. In vitro lowest observed effect concentration (LOEC) values ra...

To establish the sublethal concentrations domain, acute and chronic oral tests were conducted on caged honeybee workers (Apis mellifera L) using imidacloprid and a metabolite, 5-OH-imidacloprid, under laboratory conditions. The latter showed a 48-h oral LD50 value (153 ng per bee) five times higher than that of imidacloprid (30 ng per bee). Chronic feeding tests indicated that the lowest observ...

Low levels of human medicines (pharmaceuticals) have been detected in many countries in sewage treatment plant (STP) effluents, surface waters, seawaters, groundwater and some drinking waters. For some pharmaceuticals effects on aquatic organisms have been investigated in acute toxicity assays. The chronic toxicity and potential subtle effects are only marginally known, however. Here, we critic...

The flexible excitation system (FES) is a kind of novel with two channels for damping control. Besides the basic functions traditional systems, systems can provide reactive power support terminal voltage, and large-capacity FES improve voltage stability power-angle synchronous generator units. However, increase in capacity complication control objectives, difficulty controller design will be in...