Toxicology is the study of chemicals in or on an organism and how they are affected by these chemicals. It is very vital to know different levels of exposure to different things and to find out what is safe for humans and what is not. Their are many different ways these chemicals can get into the body. These chemicals are everywhere, small amounts do not usually harm people but large amounts can. A very strong chemical could injure you with just a small amount. One route of entry is
inhaling chemicals into the lungs. It is one of the more common routes of entry into the body in a lab setting. It is very dangerous when chemicals get into the lungs. To get to the lungs the chemical also passes through the mouth and throat. Once the chemical is in the lungs it gets into the mucus membrane and makes it difficult to breathe. Another route of exposure is absorption through the skin. Different types of chemicals can burn you if you touch them. A chemical could also give you a bad rash. You can protect yourself by wearing gloves when dealing with harmful chemicals to limit exposure to the skin. Many bottles with chemicals have if it is safe or not somewhere on the bottle. The last two exposures are injection and ingestion. In a hospital setting many types of needles are used, if you were to get poked by a used needle you are now at risk. The needled that poked you could contain a number of diseases which could now get passed on to you. Drug users who use needles are also at a very high risk of exposure when they use dirty or used needles. Ingestion would be eating something that is toxic or poisonous to humans. Many plants exist around the world and researching or knowing which ones are safe to eat are very important. One bite of a lethal plant could kill you.
Biotransformation is what the body does when a drug enters the body. The ideal goal is to get the chemical out of the body or to break it down. The body deals with the drug many different ways. One way is a phase 1 reaction. This reaction converts a drug to become more water soluble with active metabolites. Drugs that are metabolized like this have longer half lives. Phase 2 reactions also make the drug more water soluble but have inactive metabolites. Dose response is a very important aspect in toxicology. Dose response is the change in a organism based off of different levels they were exposed to. If the dose was large the organism is going to have more problems. This occurs after a certain exposure time, each chemical is different. Each chemical has a point where it becomes unsafe. Other factors also contribute to this including weight and height. If a larger person and a smaller person got exposed to the same amount of chemical, the smaller person is going to be affected more.
Ld50 is the median dose of exposure where half of those who were exposed died and the other half lived. This helps us understand what dose is lethal to humans.
