Sunday, March 19, 2017

Toxicology



Toxicology is defined as the branch of science concerned with the nature, effects, and detection of poisons. In other words it is the study of the dangerous effects of chemicals on living organisms. Chemicals may start to damage or harm the body or other living organisms when it enters or comes in contact with the body. This can happen numerous ways- inhalation (breathing), skin or eye contact, swallowing (ingestion or eating), or injection. The most typical way chemicals enter the body is through breathing contaminated air. Once a chemical is in the body it spreads through the blood stream and can damage organs. Chemicals can also be inhaled in multiple ways. The most common are through gases and vapors, mists, dust, fumes and smoke. Toxicologists also realize that even low-dose exposures that may seem minor or insignificant but may have biological meaning or lead to an adverse health effect if the exposure is continuous or happens during a critical window of development.

Biotransformation is the chemical modification made by an organism on a chemical compound. The body typically deals with a foreign compound by making it more water-soluble, to increase the rate of its excretion through the urine. There are many different processes that can occur; the pathways of drug metabolism can be divided into. Biotransformation falls under two phases- reaction I and reaction II. Reaction I includes oxidative, reductive and hydrolytic reactions which are either introduced or unmasked so the drug molecule becomes more water-soluble and can be excreted. Reaction II involves covalent attachment of small polar endogenous molecule such as glurcuronic acid, sulfate, or glycine and have a larger molecular weight. 

LD50 stands for the lethal dose of an ingested substance. It kills fifty percent of a test sample and it is expressed in milligrams of substance per kilogram of the body weight. Different chemicals cause different toxic effects, which makes comparing the toxicity or one with another is a difficult task. For instance some chemicals might damage an organ more than another, or not at all. The most efficient way to do a lethality test is to measure how much of a chemical is required to cause death. 

Toxicology has multiple factors that influence how it works and takes action on organisms. Some of these influences include it's form and innate natural chemical activity, the dosage and how frequent that dosage is, the route in which the chemical enters the body, the life-stage of the person being contaminated, gender, it's ability to be absorbed, and lastly, metabolism. It is important for people to be aware of toxic chemicals that they may be coming in contact with, especially in the work place. Drinking, filtered purified water, wearing protecting gear such as work clothes, gloves and eye wear, washing hands, and knowing the exposure times are just a few tips to prevent injury or health problems. toxicologist is a scientist or medical personnel who specializes in the study of symptoms, mechanisms, treatments and detection of venoms and toxins; especially the poisoning of people. 



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