Forensic toxicology is a branch of the field of chemistry which focuses on the study of toxins and their applications to forensics. Forensic toxicologists can examine samples of tissue and fluids from the human body to look for toxins, and they can also check for the presence of toxins in animals and the natural environment. They may be involved in a variety of criminal cases, ranging from suspected poisonings of racehorses to investigations of accusations of chemical pollution.
Like other chemists, forensic toxicologists can use a number of tools to analyze samples to see what they contain. An added layer of complexity is involved with forensic toxicology, because plants and animals metabolize toxins when they are ingested, and it is unusual to find a toxin in its original form in the body. Sometimes, forensic toxicologists look primarily for traces which indicate that a chemical was once present in the body, rather than trying to identify the chemical itself, because the chemical may be long gone.
Humans have been studying poisons and their effects for thousands of years, concerned with many of the same issues involved in modern forensic toxicology, such as how toxins are derived, what they do to the body, and how the body attempts to metabolize or eliminate them. Understanding this information can help analysts look for specific toxins.
Toxicology screens, which are routinely run on deceased individuals, are performed by a forensic toxicologist who looks for unusual chemicals or materials in the body. Sometimes, a toxicology screen reveals an unusual spike of a substance which is not necessarily toxic, but could provide information about the crime. Forensic toxicology can also involve the examination of animal remains, along with evidence found at a scene which could indicate the presence of toxins. For example, people might find dead plants near a waterway, and ask a forensic toxicologist to examine the plants and the nearby water to see if there are toxins in the water which are causing the plants to die.
In order to become a forensic toxicologist, someone must generally become a forensic chemist, and focus specifically on toxins during his or her study. Some colleges specifically offer degrees in forensic toxicology to their students. Typically a bachelor's degree in chemistry is required to work as a forensic chemist or toxicologist, along with additional training and work experience in forensics. Initially, graduates may work under the supervision of someone with more experience while they learn the nature of their work, eventually being allowed to work independently on assigned tasks.