There are generally five types of toxic entities; chemical, biological, physical, radiation and behavioural<unk> : * Disease-causing microorganisms and parasites are toxic in a broad sense but are generally called pathogens rather than toxicants. The biological<unk>  of pathogens can be difficult to measure because the "threshold dose" may be a single organism. Theoretically one virus, bacterium or worm can reproduce to cause a serious infection. However, in a host with an intact immune system, the inherent<unk>  of the organism is balanced by the host's ability to fight back; the effective<unk>  is then a combination of both parts of the relationship. In some cases, e.g. cholera, the disease is chiefly caused by a nonliving substance secreted by the organism, rather than the organism itself. Such nonliving biological toxicants are generally called toxins if produced by a microorganism, plant, or fungus, and venoms if produced by an animal. * Physical toxicants are substances that, due to their physical nature, interfere with biological processes. Examples include coal dust, asbestos fibres or finely divided silicon dioxide, all of which can ultimately be fatal if inhaled. Corrosive chemicals possess physical<unk>  because they destroy tissues, but they're not directly poisonous unless they interfere directly with biological activity. Water can act as a physical toxicant if taken in extremely high doses because the concentration of vital ions decreases dramatically if there's too much water in the body. Asphyxiant gases can be considered physical toxicants because they act by displacing oxygen in the environment but they are inert, not chemically toxic gases. * Radiation can have a toxic effect on organisms. * Behavioral<unk>  refers to the undesirable effects of essentially therapeutic levels of medication clinically indicated for a given disorder (DiMascio, Soltys, & Shader, 1970). These undesirable effects may include anticholinergic effects, alpha-adrenergic blockade, and dopaminergic effects, among others.
Toxicity
Neurotoxicity
Cardiotoxicity
Phototoxicity
Ototoxicity
Side effect
Acute toxicity
Hepatotoxicity