Abstract:
Harmfulness is how much a synthetic substance or a specific combination of substances can harm an organism. Toxicity can allude with the impact on an entire creature, like a organism, bacterium, or plant, just as the impact on a base of the living being, like a cell (cytotoxicity) or an organ like the liver (hepatotoxicity). Likewise, the word might be figuratively used to depict poisonous consequences for bigger and more perplexing gatherings, like the complex family or society on the loose. Now and then the word is pretty much inseparable from harming in regular utilization.

A central concept of toxicology is that the effects of a toxicant are dose-dependent; even water can lead to water intoxication when taken in too high a dose, whereas for even a very toxic substance such as snake venom there is a dose below which there is no detectable toxic effect. Considering the limitations of this dose-response concept, a novel Drug Toxicity Index (DTI) has been proposed recently. DTI redefines drug toxicity, identifies hepatotoxic drugs, gives mechanistic insights, predicts clinical outcomes and has potential as a screening tool. Toxicity is species-specific, making cross-species analysis problematic. Newer paradigms and metrics are evolving to bypass animal testing, while maintaining the concept of toxicity endpoints.

TYPES
There are generally three types of toxic entities; chemical, biological, physical:
 CHEMICAL TOXICANTS include inorganic substances such as,  lead , mercury, hydrofluoric acid  , and chlorine gas, and organic compounds such as methylalchohol , most medications, and toxins. While some weakly   radioactive substances, such as uranium, are also chemical toxicants, more strongly radioactive materials like radium are not, their harmful effects (radiation poisoning) being caused by the ionizing radiation produced by the substance rather than chemical interactions with the substance   itself.

DISEASE-CAUSING MICROORGANISMS and parasites are toxic in a broad sense but are generally called pathogens rather than toxicants. The biological toxicity 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 system, the inherent toxicity of the organism is balanced by the host's ability to fight back; the effective toxicity is then a combination of both parts of the relationship. In some cases, eg .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 fibers or finely divided silicon dioxide, all of which can ultimately be fatal if inhaled. Corrosive chemicals possess physical toxicity 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.

Submit manuscript  at  https://www.scholarscentral.org/submissions/toxicology-open-access.html  or send as an e-mail attachment to the Editorial Office at toxicol@peerjournal.org

Kind regards

Managing editor              

Catherine

Toxicology: Open Access