To evaluate the relative toxicity and the occurrence patterns of pesticide mixtures in streams draining agricultural watersheds, a 3-step approach was used. First, a landscape of interest was identified, defined, and isolated. Second, the relative toxicity of mixtures, on the basis of pesticide toxicity index scores, was compared with the relative toxicity of the highest individual pesticide, o...

Pesticide mixtures are common in streams with agricultural or urban influence in the watershed. The Pesticide Toxicity Index (PTI) is a screening tool to assess potential aquatic toxicity of complex pesticide mixtures by combining measures of pesticide exposure and acute toxicity in an additive toxic-unit model. The PTI is determined separately for fish, cladocerans, and benthic invertebrates. ...

BACKGROUND agricultural pesticide poisoning is a major public health problem in the developing world, killing at least 250,000-370,000 people each year. Targeted pesticide restrictions in Sri Lanka over the last 20 years have reduced pesticide deaths by 50% without decreasing agricultural output. However, regulatory decisions have thus far not been based on the human toxicity of formulated agri...

chlorpyrifos is one of the organophosphate pesticides that are commonly used to control insects in domestic activities and many agricultural farms that are located in close to water sources. hence, the present study, investigate the lethal toxicity of this pesticide. in this study, fish were treated in groups of 21 with different concentrations of chlorpyrifos (aria brand with active ingredient...

Pesticides, such as parathion, are metabolized by cytochrome p-450 system to paraoxon, which is a potent cholinesterase inhibitor. Paraoxonase (PON) catalyzes the hydrolysis of these toxic metabolites and protects against pesticide toxicity. A glutamine/arginine (Gln/Arg) polymorphism at amino acid position 192 of PON has been described. The Arg/Arg genotype is associated with higher serum para...

the use of adjuvants enhances the insecticide efficiency and increases the persistence of insecticides. in this study, the effect of adjuvants on the toxicity of chlorpyrifos and cyhalothrin formulations were investigated under laboratory and field conditions. the comparative toxicity of two chlorpyrifos [(48% emulsifiable concentrate (ec)] formulations (dursban and pyrifos el nasr), two cyhalo...

Pesticide applications to agricultural lands in California, USA, are reported to a central data base, while data on water and sediment quality are collected by a number of monitoring programs. Data from both sources are geo-referenced, allowing spatial analysis of relationships between pesticide application rates and the chemical and biological condition of water bodies. This study collected da...

background: diazinon is an organophosphorous pesticide which widely found in municipal, agricultural, and urban storm water discharges. the present study was conducted to achieve lethal concentration (lc50) and behavioral changes of rutilus rutilus caspius and hypophthal-micthys molitrix after exposure to lethal concentration of diazinon. methods: the experiment was carried out in static condit...

The toxicity of a nutrient-pesticide mixture in nonvegetated and vegetated sections of a constructed wetland (882 m² each) was assessed using Hyalella azteca 48-h aqueous whole-effluent toxicity bioassays. Both sections were amended with a mixture of sodium nitrate, triple superphosphate, diazinon, and permethrin simulating storm-event agricultural runoff. Aqueous samples were collected at infl...