Introduction:
The word ‘toxicology’ comes from Greek words ‘toxicon’ which means ‘poisons’. Thus, toxicology is study of poisons.
- Toxicology can be defined as the study of poisons and their harmful effects on living organism. It includes the sources of poisons, their identification, physicochemical properties, toxicity including median lethal dose, factors affecting toxicity, toxicokinetics, toxicodynamics, clinical signs of toxicity, postmortem changes, histopathology, diagnosis including differential diagnosis, analytical procedures and principle of treatment of condition that they cause.
- It also includes study of special effects of toxicants such as carcinogenesis, teratogenesis, mutagenesis, immunotoxicity, neurotoxicity, reproductive toxicity and ecotoxicity, etc.
Poisons: Any substance which when taken inwardly or applied in any kind of manner to body; depresses the health or destroys life.
Toxicity: It is the inherent capacity of substance to produce toxic effects or detrimental changes on the organisms.
Toxicosis:It is state resulting from exposure to a poison.
Toxins:Toxicants or poisonous substances liberated/ produced by living organisms and generally not well defined chemically. Depending on their origin toxin can are grouped as:
- Phytotoxins: Plant toxins
- Mycotoxins: Fungal toxins
- Zootoxins: Toxins of lower animals. Ex: bufotoxin, snake venom
- Bacterial toxins: liberated by bacterial cells. It is further of two types:
- Endotoxins: Found within or as part of bacterial cells
- Exotoxins: elaborated from bacterial cells.
Toxinology: Branch of toxicology that deals with the study of toxic effects of toxin.
Hazard or risk: It is likelihood of poisoning of a living organism after exposure to particular toxicant.
Toxicant: A poison that is made by humans or that is put into the environment by human activities.