Toxicology: General Information
In a general sense, toxicology can be defined as toxin science or the "science of poisons". The main divisions of the study of toxicology involves the source of toxins, physical, chemical, and biological properties of toxins, toxic doses, the changes that occur in living organisms, and their effects, treatment of toxic diseases, isolation of toxins, analysis of toxins, and regulations about toxins. Toxicology frequently deals with foreign substances that are apart from those necessary for the normal metabolism of a living organism. In recent years, these foreign substances have been called xenobiotics.
Toxicology also deals with substances that are necessary for the body, such as hormones, amino acids, vitamins, and exogenous substances, such as food additives, that have toxic effects at high levels. Many toxic events have occurred in recent years due to the increased use of industrial, agricultural, and household chemical substances, and with the use of nuclear energy. These chemical effects affect the whole biosphere, as well as human beings. The investigation of these chemical in biological systems and the environment, and the methodology are the subjects of science and chemistry, while their metabolism, effects, and changes at molecular level are the subjects of biochemistry. The investigation of the toxic effects that occur as the result of the usage of these chemicals are related to the sciences of medicine, agriculture, and food. Toxicology is a multi-disciplinary science with close relationships with other sciences such as: pharmacology, immunology, biology, pathology, chemistry, biochemistry, immunology, food, and public health.
Toxicology: History of
Toxin science is as old as the primitive societies. Toxins can be defined as substances that may cause adverse health effects under the conditions in which they are produced and used. Archaeological research has shown that ancient people knew about toxins of animal, plant, and mineral origin. Native Americans used the extracts of toxic plant seeds that involved toxic glycosides as weapons. At that stage of history, toxins were regarded as tools of war, used by people to defend themselves against enemies. The papyrus scrolls of Egypt, are known to be the oldest information sources about toxicology, Ebers papyrus written in 1552 BC, the oldest written medical record, involves more than 800 toxins, and explains the production of toxins such as belladonna, and opium alkaloids, lead, antimony, and copper.
Rational medicines, began in the times of the ancient Greeks, Hippocrates(460-315 BC) used toxins in the treatment of certain diseases, while adding new toxic substances in the area of medicine. He also established the basis of industrial hygiene and toxicology.
Paracelsus was regarded as a "Renaissance man" in the history of science and medicine. He is the creator of the basic scientific discipline of toxicology. He created the focus on the "toxicon", the toxic agent,, as a chemical entity, and emphasized, the study of the relation of chemical structure to toxicity. He declared that experimentation is essential in examination of the responses of living organisms to chemicals, and the therapeutic or toxic effects could be confirmed be regarding the doses of these chemicals. This was the first significant description of the dose-response relation, which is regarded as the building block of toxicology science.
Matthieu Joseph Bonaventura Orfila (1787-1853), a Spanish scientist, is known to be the establisher of modern toxicology. He was a medical doctor who specialized in chemistry and physiology after completing his education in medicine. He was the first person to find a systematic relationship between the chemical and biological effects of toxins. He distinguished toxicology as a distinct discipline, as a the study of poisons. His main contribution was discovering that toxins did not just accumulate in the stomach, but distributed to several organs throughout the body. In this way, Orfila established the basis of analytical toxicology, forensic toxicology, which are the main divisions of modern toxicology.
In the 20th century, developments occurred rapidly, and effects of several toxic substances, including their mechanisms, were investigated. The concept of antidote for specific toxic substances and treatments for toxic diseases were evolved. Developments that led to the discovery and understanding of toxic substances and the treatments for use by man included the discovery and study of DDT and organophosphate insecticides. The advancement in technology that occurred through the studies related to analytical sensitivity has created the necessity of regarding technology as a science and subdividing it into several branches,