Persistence environmental fate

Characteristics (physical appearance/odor, stability, persistency, environmental fate)... 

Toxins can be persistent or non-persistent. Generally, Toxins are non-persistent. Environmental Fate ... 

Environmental Fate. A portion of releases to land and water will quickly evaporate, although some degradation by microorganisms will occur. Xylene are moderately mobile in soils and may leach into groundwater, where they may persist for many years. Xylenes are VOCs. As such, xylene will react with other atmospheric components, contributing to the formation of ground-level ozone and other air pollutants. 

The CESARS database contains comprehensive environmental and health information on chemicals. It provides detailed descriptions of chemical toxicity to humans, mammals, aquatic and plant life, as well as data on physical chemical properties, and environmental fate and persistence. Each record consists of chemical identification information and provides descriptive data on up to 23 topic areas, ranging from chemical properties to toxicity to environmental transport and fate. Records are in English. Available online through CCINFOline from the Canadian Centre For Occupational Health and Safety (CCOHS) and Chemical Information System (CIS) on CD-ROM through CCIN-FOdisc. 

Physical and Chemical Properties. The physical/chemical properties of endosulfan are sufficiently well characterized to enable assessment of the environmental fate of the compound (Budavari 1996 Coleman and Dolinger 1982 EPA 1982c, 1987b Hansch and Leo 1995 HSDB 1999 Metcalf 1995 NIOSH 1997 Sitfig 1980 Suntio et al. 1988 Tomlin 1994). The relative persistence of the two isomers and the potential for conversion from one isomer to another may also deserve further study. 

The environmental fate and behavior of compounds depends on their physical, chemical, and biochemical properties. Individual OPs differ considerably from one another in their properties and, consequently, in their environmental behavior and the way they are used as pesticides. Pesticide chemists and formulators have been able to exploit the properties of individual OPs in order to achieve more effective and more environment-friendly pest control, for example, in the development of compounds like chlorfenviphos, which has enough stability and a sufficiently low vapor pressure to be effective as an insecticidal seed dressing, but, like other OPs, is readily biodegradable thus, it was introduced as a more environment-friendly alternative to persistent OCs as a seed dressing. 

Environmental fate Persistence - P Soil or sediment >1 80 Soil, sediment >50 to Soil, sediment 30 to Soil, sediment <30 days... 

Environmental Fate. Hydrogen sulfide is known to easily evaporate into the air (EPA 1993 Layton and Cederwall 1986 Leahey and Schroeder 1986), although its solubility in water may also cause it to persist in unperturbed, anoxic sediments. Additional information on the transport, transformation, and persistence of the compound in soils and groundwater, particularly at hazardous waste sites, would be useful in identifying the most important routes of human exposure to hydrogen sulfide. 

The environmental fate of chemicals describes the processes by which chemicals move and are transformed into the environment. Environmental fate processes that should be addressed include persistence in air, water and soil reactivity and degradation migration in groundwater removal from effluents by standard waste-water treatment methods and bioaccumulation in aquatic or terrestrial organisms. 

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