Ecotoxicological effects of the diphenyl ether herbicide fomesafen, applied alone or in combination with the adjuvant Agral 90 (mixture of polyethoxylated derivatives of nonylphenol), were assessed on planktonic communities in 18-m3 outdoor mesocosms during a nine-month study. Four mesocosms were treated with fomesafen only (nominal concentration: 40 microg/L), four were treated with the mixtur...

BACKGROUND Both coplanar and noncoplanar polychlorinated biphenyls (PCBs) exhibit neurotoxic effects in animal studies, but individual congeners do not always produce the same effects as PCB mixtures. Humans genetically have > 60-fold differences in hepatic cytochrome P450 1A2 (CYP1A2)-uninduced basal levels and > 12-fold variability in aryl hydrocarbon receptor (AHR)affinity; because CYP1A2 is...

Faba bean plants (Vicia faba) showed remarkable resistant to wilt disease caused by Fusarium solani pv. Phaseoli when watered with a mixture of heavy metal at a concentration 10mg/L. However the use of Zn, Pb alone slightly increases the susceptibility of bean plants to Fusarium wilt. Plants exposed to Cd or Cu treatment accelerate the symptoms appearance in infected plant. The toxicity of a si...

The approaches to assessing the joint action of components of a mixture are based in large measure on the conceptual groundwork laid by Bliss (1939) and Finney (1971), and are mathematical rather than biological in nature. The approaches commonly known as dose addition and response addition, discussed in the following sections, are non-interactive forms of joint action that assume the chemicals...

Twenty-five pesticides used in the production of rice and soybeans in Texas were tested in the laboratory to determine their toxicity to the eggs of Psorophora columbiae. A reduction in hatching rate occurred when eggs were treated with a herbicide formulation containing thiobencarb and with one containing a tank mixture of propanil and molinate. A carbaryl formulation induced hatching of eggs ...

Mixtures of metals are often present in surface waters, leading to toxicity that is difficult to predict. To provide data for development of multimetal toxicity models, Daphnia magna neonates were exposed to individual metals (Cd, Cu, Ni, Zn) and to binary combinations of those metals in standard 48-h lethality tests conducted in US Environmental Protection Agency moderately hard reconstituted ...

Mixtures of organochlorine compounds have the potential for additive or interactive toxicity to organisms exposed in the stream. This study uses a variety of methods to identify mixtures and a modified concentration-addition approach to estimate their potential toxicity at 845 stream sites across the United States sampled between 1992 and 2001 for organochlorine pesticides and polychlorinated b...

The toxicity of cadmium and zinc at concentrations ranging from 0.1 to 100 microg/l was investigated against the activity of Diplostomum spathaceum (Rudolphi, 1819) cercariae. Over a 24 h exposure period a significant reduction in cercarial activity occurred in solutions of cadmium, zinc, and a mixture of cadmium and zinc at all concentrations. Reduced cercarial activity also occurred in all to...

The identification of toxic A species and/or the process of their formation is crucial for understanding the mechanism(s) of A neurotoxicity in Alzheimer disease and also for the development of effective diagnostic and therapeutic interventions. To elucidate the structural basis of A toxicity, we developed different procedures to isolate A species of defined size and morphology distribution, an...

Higher efficacy of mixture of insecticides with synergists piperonyl butoxide (PB) was reported in controlling in the Dooars population of Helopeltis theivora Waterhouse. Therefore, the use of synergists as one of the countermeasures against the insecticide resistance problem of H. theivora is recommended. The combination of deltamethrin +PB (piperonyl butoxide), quinalphos +PB and imidacloprid...