Arsenical

Arsenical

Arsenicals are a class of chemical compounds that contain the element arsenic. These compounds have been used historically in various applications, including medicine, agriculture, and industry. Arsenicals can be organic or inorganic, with varying degrees of toxicity.

History

Arsenicals have been known and used since ancient times. The ancient Greeks and Romans used arsenic compounds for medicinal purposes and as poisons. In the 19th and early 20th centuries, arsenicals were widely used in medicine to treat diseases such as syphilis and trypanosomiasis. One of the most famous arsenical drugs was Salvarsan, developed by Paul Ehrlich in 1909.

Types of Arsenicals

Arsenicals can be broadly classified into two categories: organic and inorganic.

Inorganic Arsenicals

Inorganic arsenicals include compounds such as arsenic trioxide, arsenic pentoxide, and arsenic acid. These compounds are highly toxic and have been used as pesticides, herbicides, and wood preservatives.

Organic Arsenicals

Organic arsenicals contain carbon-arsenic bonds and include compounds such as arsenobetaine and arsenocholine. These compounds are generally less toxic than inorganic arsenicals and are found in some marine organisms.

Uses

Arsenicals have been used in various fields:

Medicine

In the past, arsenicals were used to treat diseases such as syphilis, trypanosomiasis, and leukemia. However, due to their toxicity, their use has declined with the development of safer alternatives.

Agriculture

Arsenicals have been used as pesticides and herbicides. Compounds such as lead arsenate and calcium arsenate were commonly used to control insect pests and weeds.

Industry

In industry, arsenicals are used in the production of semiconductors, glass, and alloys. Arsenic trioxide is used in the manufacturing of optical glass and as a decolorizing agent.

Toxicity

Arsenicals are known for their toxicity. Exposure to arsenic compounds can lead to various health issues, including skin lesions, cancer, and cardiovascular disease. Chronic exposure to arsenic-contaminated water is a significant public health concern in some regions.

Regulation

Due to their toxicity, the use of arsenicals is regulated in many countries. Agencies such as the Environmental Protection Agency (EPA) and the World Health Organization (WHO) have set guidelines for acceptable levels of arsenic in drinking water and food.

Related Pages

• Arsenic
• Salvarsan
• Paul Ehrlich
• Syphilis
• Trypanosomiasis
• Lead arsenate
• Calcium arsenate
• Environmental Protection Agency
• World Health Organization