Arsenic-containing compounds, herbicide

The oxide is obtained from the sulfide by roasting it in air. The stable form of arsenic is the gray or metallic form although other forms are known. Yellow arsenic is obtained by cooling the vapor rapidly, and an orthorhombic form is obtained when the vapor is condensed in the presence of mercury. Arsenic is used in the production of a variety of insecticides and herbicides, and in alloys with copper and lead. Some arsenic compounds are important medicinal compounds and a number of pigments contain arsenic compounds. The surface tension of lead is increased by dissolving a small amount of arsenic in it. This allows droplets of molten lead to assume a spherical shape, and this fact is utilized in the production of lead shot. 

Some inorganic arsenic compounds are also used as herbicides. These inorganic arsenicals are general protoplasmic poisons and are therefore hazardous to both plant and animal life. Affected dogs almost always vomit, have severe abdominal pain, and develop bloody diarrhea. The vomitus may contain mucous shreds and blood from erosion of the gastric and intestinal epithelium. 

Pesticides used around the house and garden include insecticides, herbicides, rodenticides, fungicides, and fumigants. Toxic chemicals contained in pesticides include organochlorine and organophosphate compounds, carbamates, and arsenicals. The solvents used as carriers for these include aliphatic and aromatic hydrocarbons, alcohols, and glycol ethers. I34l... 

Herbicides are used to kill plants. Sodium chlorate, NaC103 and sodium arsenite, Na3As03, were commonly used as weed killers in the first half of the twentieth century, but inorganic arsenic compounds, in particular, are toxic to mammals. Organic herbicides are now used. They are much more toxic to certain types of plants than to others, so they can be used as selective weedkillers. Atrazine, which is a member of a class of herbicides called the triazines, is widely used to kill weeds in cornfields. The triazines contain six-membered rings with alternating carbon and nitrogen atoms. The effects of atrazine on human health are not yet clear. 

Arsenic, most commonly used as arsenic (III), is involved in processes associated with glass works copper, zinc and lead smelters the production of pesticides and herbicides and semiconductors (Hartwig et al. 1997). Although the commercial use and production of substances containing arsenic have decreased over the past few decades (Hartwig et al. 1997)> it is still an occupational hazard. In March of 1998, the German employers insurance company reported 34 total accepted cases of diseases, including cancer, related to arsenic or its compounds from 1994 to 1996 (Arbeitsmed Sozialmed Umweltmed 1998). 

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