This research characterized the effects of water quality and organism age on the toxicity of nickel (Ni) to fathead minnows (Pimephales promelas) to facilitate the accurate development of site-specific water-quality criteria. Nickel sulfate hexahydrate (NiSO4 x 6H2O) was used as the Ni source for performing acute toxicity tests (median lethal concentration after 96-h exposure [96-h LC50]) with ...

Of three proposed acute toxicity models, the uptake-depuration (UD) model, the time-integrated concentration (TIC) model, and the concentration-time (CT) model are derived and verified with acute toxicity data to estimate the internal residues of waterborne metals in fish as a function of a few constants and variables. The main factors are the exposure time, the external exposure concentration,...

Background: Chlorpyrifos is an organophosphate pesticide that elicits broad-spectrum insecticidal activity against a number of important arthropod pests. Determining the insecticides’ toxicity to amphibians can give us a better understanding regarding the role of toxicants in amphibian declines. This information would be beneficial to assess their ecological relevance at environmental con...

the purpose of the present study was to determine the acute toxicity (lc 50 ) of hgcl 2 and cuso 4 in caspian roach ( rutilus caspicus ) and cuso 4 in caspian kutum ( rutilus kutum ). the caspian roach lc 50 values for hgcl 2 at 24, 48, 72, and 96-hrs of exposure, were 0.64, 0.61, 0.42, and 0.28 mg l -1 , respectively, and for cuso 4 were 11.55, 5.08, 2.49, and 1.47 mg l -1 , respectively. the ...

Neonicotinoids are subjected to vigilance because of environmental contaminations and deleterious effects on bees. Imidacloprid (IMI) is one of the most representative insecticides of this family. At chronic exposure, concentration-effect relationships are non linear. An insect model should allow a better description of this toxicity. We compared the lethal concentration 50% (LC50) of IMI for a...

The aim of this study was to investigate acute toxicity (96-hr LC50 and lethal concentrations) of waterborne metal mixture (Pb+Mn) for the fish, Catla catla, Labeo rohita, Cirrhina mrigala, Ctenopharyngodon idella and Hypophthalmichthys molitrix. The extent of metals bio- accumulation in fish body organs viz. gills, liver, kidney, fins, bones, muscle and skin at both 96-hr LC50 and lethal conce...

Assessment of contaminant impacts to federally identified endangered, threatened and candidate, and state-identified endangered species (collectively referred to as "listed" species) requires understanding of a species' sensitivities to particular chemicals. The most direct approach would be to determine the sensitivity of a listed species to a particular contaminant or perturbation. An indirec...

Hematological parameters are suitable biomarkers for evaluating the potential risk of the chemicals. The aim of this study was to investigate of acute crude oil exposure on basic physiological functions of Persian sturgeon, Acipenser persicus. 210 juvenile Persian sturgeon (9.4 ± 1g) were supplied by the Rajaei fish farm in Mazandaran Province, Iran.  Juveniles were exposed to the crude oil (15...

Essential oils of sixteen Chinese medicinal plants were screened for fumigant toxicity against Bemisia tabaci. The essential oil of Allium sativum exhibited the strongest fumigant activity against B. tabaci with an LC50 value of 0.11 μg/l followed by the essential oils of Agastache rugosa (LC50 = 7.08 μg/l), Illicium verum (LC50 = 8.61 μg/l), Chenopodium ambrosioides (LC50 = 8.80 μg/l), and Syz...