22.1: Natural Poisons and Food Poisoning 22.2: Poisons and How They Act 22.3: More Chemistry of the Nervous System 22.4: The Lethal Dose 22.5: The Liver as a Detox Facility 22.6: Carcinogens and Teratogens 22.7: Hazardous Wastes What is Toxicology ? Toxicology is traditionally defined as "the science of poisons." Over time, our understanding of how various agents can cause harm to humans and other organisms has increased, resulting in a more descriptive definition of toxicology as "the study of the adverse effects of chemical, physical, or biological agents on living organisms and the ecosystem, including the prevention and amelioration of such adverse effects." These adverse effects can take many forms, ranging from immediate death to subtle changes not appreciated until months or years later. They may occur at various levels within the body, such as an organ , a type of cell , or a specific biochemical. Our understanding of how toxic agents damage the body has progressed along with medical knowledge. We now know that various observable changes in anatomic or bodily functions actually result from previously unrecognized changes in specific biochemicals in the body. A poison is any substance that is harmful to your body. You might swallow it, inhale it, inject it, or absorb it through your skin. Any substance can be poisonous if too much is taken. Poisons can include Prescription or over-the-counter medicines taken in doses that are too high Overdoses of illegal drugs Carbon monoxide from gas appliances Household products , such as laundry powder or furniture polish Pesticides Indoor or outdoor plants Metals such as lead and mercury The effects of poisoning range from short-term illness to brain damage, coma, and death. To prevent poisoning it is important to use and store products exactly as their labels say. Keep dangerous products where children can't get to them. Treatment for poisoning depends on the type of poison. Sources National Institute of Health (NIH) US National Library of Medicine