what is toxicology ?

TOXICOLOGY
Toxicology is a science that deals with the study of the adverse effects of chemical on living organisms.The word is derived from two words , Toxicon meaning poison and logos meaning discourse.Therefore , Toxicology involves the study of poisons.That is their biological activity and effects,procedures for detecting their presence and the treatment of the poisoned patient.Poison are substances(chemical/drugs)that cause harmful,dangerous of fatal symptoms in animals and human beings.The word poison is mostly used for legal purposes.Many drugs in large doses act as poisons.For example barbiturates can cause toxic effects in large doses.Other common agents having toxic or fatal effects include insecticides and pesticides heavy metals , industrial products(acids and alkalies)or Environmental pollutants present in air , water or food.
DEVLOPMENT OF TOXICOLOGY
The awareness of toxic effects of drugs and their legal aspects is recent , the knowledge of toxic effects of animal venoms and poisonous arrow for hunting and warfare has been reported even in prehistoric times.Hindu mythology and vedic literature give the description of use of metals, opium preparation and other toxic substances.
Paracelsus(16th century)the greek physician made the first scientific observation that “All substance are poisons, there is none that is not a poison.The rifht dose differentiatesa poison and a remedy”.This classic observation holds good even today and perhaps forms the basic of modern toxicology.Claude Bernard (1813 - 1878) who studied the physiology of arrow poison(Tubocurarine)gave the impetus to the devlopment of toxicology in Europe during 19th century.
Devlopment of antidotes for arsenic war gas (BAL,British anti Lewisite) used in the second world war,discovery of presticides,insecticides(DDT,Dichloro-Diphenyl-Trichloroethane),other organophosphorous compounds and more particularly,the thalidomid tragedy have changed the face of toxicology in the last 50years.
SCOPE OF TOXICOLOGY
It is a brsnch of pharmacology,toxicology has devloped in to full discipline in itself.The following scopes are
TOXICOLOGIST:- A specialist who is a trained pharmacologist involved in the study of poisons,adverse or toxic effects of drugs.
DESCRIPYIVE TOXICOLOGIST:- Investigates or evaluates risks of chemical exposure to man and environment.
REGULATORY TOXICOLOGIST:- Determines or sets regulatory control for drugs and chemical for their toxic doses or levls. He works under the regulatory control of the druf regulatory aythorities.
FORENSIC TOXICOLOGIST:- It is concerned with the medicolegal aspects of the use of chemical and drugs that are harmful to man and animals.His functions combine both analytical chemistry and fundamental toxicology.He assists in postmortem, investigations,helps in establishing the cause of death.He gives medicolegal opinion in the case of death due to poison of toxicity.
CLINICAL TOXICOLOGIST:- Focuses on dieases that are caused by or uniquely associated with toxic substances.A clinical toxicologist is a well trained physician who differentiates,diagonoses and treat patients who are poisoned by drugs and other toxic chemical or substances.
The following is the sequences of toxicology, and a toxicologist encompases all these aspects.
Therapeutic dose à Side effects à Adverse effects
Toxic dose à Toxic effects.