Showing papers in "Bulletin of Environmental Contamination and Toxicology in 2002"

Toxicity of Stormwater Runoff After Dormant Spray Application of Diazinon and Esfenvalerate (Asana®) in a French Prune Orchard, Glenn County, California, USA

Abstract: Organophosphate pesticides (OPs), in particular diazinon and chlorpyrifos, have frequently been detected in toxic concentrations in waterways draining agricultural and urban areas in California’s Sacramento and San Joaquin River watersheds (US Geological Survey 1997, Werner et al. 2000). Toxicity has in part been linked to stormwater runoff of OP pesticides applied during the dormant season on stonefruit and almond orchards (Foe and Sheipline 1993; Kuivila and Foe 1995). State Water Quality Plans have now been implemented by regulatory agencies to prevent movement of OPs into surface water, and growers have reduced the application of OPs. Simultaneously, the use of so-called reduced-risk alternatives, such as pyrethroid insecticides and Bacillus thuringiensis bloom sprays, has increased dramatically (Epstein et al. 2000).

Toxicity of ionic and nonionic surfactants to six macrobes found in Agra, India.

Abstract: Surfactants or surface active agents are substances that when dissolved in a liquid especially water can reduce its surface tension and thus can allow it to foam or penetrate solids. Surface active means they tend to adsorb on surfaces. They are helpful in wetting. Commercial surfactants are synthetic organic chemicals used in large amounts in detergents, soaps, shampoos, fabric softeners, mining and oil field chenricals, leather and food additives, food emulsifiers, pesticides, herbicides, defoliants, insecticides, antiseptics, disinfectants etc. They are present in several combinations such as detergents and household cleaning products. Granular and liquid detergents are complex mixtures containing as many as 20-30 constituents including 4-5 surfactants, dyes, enzymes, builders and stabilizers. Dispersants that are added to oil spills may contain as much as 75% surfactant (Crossland et al. 1992). Thus, they find applications in almost every chemical industry. They are also used for environmental protection. Surfactant enhanced subsurface remediation is being evaluated as an innovative technology for expediting grow1dwater remediation. Surfactants generally consist of polar or hydrophilic groups, like-COO--, -S03-, NH4+, soluble in water and oily or lipophilic groups soluble in lipids. They are of four types: anionic, nonionic, cationic and zwitterionic. Alkyl sulphates (AS), linear alkylbenzene sulphonates (LAS), alkyl ethoxy sulphates (AES), alkyl ethoxylates (AE), alkyl phenol ethoxylates (APE) and quaternary amm onium compounds are commonly used commercial surfactants.