1. Discuss on the different subfields of toxicology. There are many subfields of toxicology. One of them is mechanistic toxicology. It is the study on how a chemical causes toxic effects. The investigation in mechanistic toxicology involves the absorption, distribution and excretion. The work can be in academic settings or private industries. Another subfield of toxicology is the descriptive toxicology. It is about the evaluation of toxicity of drugs, foods and other products. The work can be in pharmaceutical or academic setting. Another subfield of toxicology is the clinical toxicology. Clinical toxicologists are usually physicians or veterinarians interested in the prevention, diagnosis, and treatment of poisoning cases. They have specialized training in emergency medicine and poison management. Another subfield of toxicology is the forensic toxicology. It is the study of the application of toxicology to the law. Forensic toxicologist uses chemical analysis to determine the cause and circumstances of death in a post-mortem investigation. Another subfield of toxicology is the environmental toxicology. It is the study of the effects of pollutants on organisms, populations, ecosystems and the biosphere. Another subfield of toxicology is the regulatory toxicology. In this subfield, regulatory toxicologist use scientific data to decide how to protect humans and animals from excessive risk. This type of toxicologist is employed by government bureaus such as FDA and EPA. 2. Describe the fundamental rules of toxicology 1. Exposure must first occur for the chemical to present a risk. 2. The magnitude of risk is proportional to both the potency of the chemical and the extent of exposure. 3. "The dose makes the poison". The amount of chemical at the target site determines toxicity. 3. Find common toxicology-associated terminology and define them. Poison: Any agent capable of producing a deleterious response in a biologic system. Exposure: The condition of being subjected to something, as to infectious agents, extreme of weather or radiation, which may have a harmful effect. Toxicity: The adverse effects that a chemical may produce. Dose: The amount of a chemical that gains access to the body. Hazard: The likelihood that the toxicity will be expressed.