Toxicology can be defined as the branch of science which deals with the properties, lethal dose, effects, signs and symptoms, diagnosis, treatment and the postmortem findings in the cases of poisoning. Toxicology is also known as the study of the adverse effects of Xenobiotics.
The term “Xenobiotics” is derived from the Greek word “Xeno” which means ‘Foreign’ and “bios” meaning ‘life’.
Toxicology is a wide field and therefore, has several branches or types of toxicology. Those branches or types include Analytical Toxicology, Environmental Toxicology, Industrial Toxicology, Forensic Toxicology, Clinical Toxicology, Veterinary Toxicology, etc.
Forensic Toxicology is the branch of Forensic science in which a Forensic Toxicologist applies the knowledge in determining the medical evidence to establish the extent of poison used or involved in the death of a person. It is determined by examining different tissues of the body.
Some common terms used in Forensic Toxicology
- Poison:- Any substance whether liquid, liquid or gaseous is inhaled, ingested or administered causes substantial damage to any organ of the body, then that substance is termed as Poison.
- Toxicity:- Toxicity refers to the degree/extent to which any substance causes damage to the body.
- Dose:- It is the amount of substance/chemical entering the body. It is usually calculated as mg of substance/kg of body (mg/kg).
- Drug:- According to WHO Drug is any substance or product that is used or proposed to be used to modify or explore physiological systems or pathological states for the benefit of the recipient.”
- Toxicosis:- Toxicosis can be defined as any condition or disease caused by the administration of poison.
- Toxicant:- Any substance which causes a harmful effect when it comes in contact with a living organism in high concentrations.
- Toxin:- It is any toxicant which is produced within an organism or by an organism. For example:- Pyrethrins.
History of Forensic Toxicology
History of Forensic Toxicology dates back to ancient times, however, most of the work has either been lost or not found. Although, it can be termed as the oldest practical sciences due to the need of the people to avoid dangerous and poisonous substances. In those times, poisoning was caused by either carelessness, lack of information, ignorance or deliberate activities.
The earliest published attempt to classify attempt dates back to 50 AD of Dioscorides, a greek employee in the Roman empire. Between the time of Galen (131-200 AD) and Paracelsus (1493-1541), a few advancements were made in the field of Toxicology and medicine.
However, it was the work of Paracelsus which laid the foundation of Toxicology. He was termed as the Father of Toxicology for his contributions. He was a physician, an alchemist who set the basics for Pharmacology, Therapeutics and toxicology. He investigated about the dose and its response.
His famous statement stated that “All substances are poisons, there is none which is not a poison. Only the dose of the substance differentiates between poison and remedy”.
In other instance of history, an event occurred where King Mithridates used to examine poisons on the criminals and drink a cocktail of poison himself to prevent himself from being poisoned.
In the 18th century, another development was made by Ramazini. He published a book on Diseases of workers in 1700 due to which he was being recognised as the father of occupational medicine.
Other developments included the role of Soot in scrotal cancer in chimney sweeps in 1775 by Percival Pott which was overshadowed by the correlation of nasal cancer and snuff use in 1761 by Hill.
Until 1700, convictions were based on the circumstantial evidence rather than the identification of the actual toxicant used. In 1781, Joseph Plenic stated that identification of the poison in the body’s organs in the only true sign of poisoning.
19th century saw an uplift in Forensic Toxicology as many developments followed. 1n 1814, Mathieu Orfila (1787-1853) published the first complete work on poisons and legal medicine titled “Traite Des Poisons”. His contribution led to his recognition as the Father of Modern Toxicology.
In 1836, Marsh developed a test for the detection of Arsenic in tissues which was successfully tested and used to convict the criminal through legal proceedings by Mathieu Orfila in 1839.
With new developments in the instruments and tests for detecting poisons, toxicology was beneficial in the legal proceedings to bring light to justice and truth. In the modern era, the advancements have been widened which has made it even more valuable to the world.
Read also: Introduction to Criminal Profiling
Role of Forensic Toxicologist
A Forensic Toxicologist plays a vital role in establishing whether any poison or drug was the cause of death of a person. In ancient times, poisoning was considered a safe passage for the criminals to commit a crime. However, recent developments and researches have assured that poisoning will not go undetected and the guilty must be found.
Poisons are frequently used in suicide and homicides and in some cases one may take it accidentally. Forensic Toxicologist work on various samples of tissues and bodily fluids responsible to detect the drugs or poisons in the body. Forensic Pathologist or the crime scene investigators send the various samples to the Forensic Toxicology lab for the testing of samples.
The samples may be of any kind and a Forensic Toxicologist must have proper knowledge about different kind of poisons so that they can be detected. They must have patience and skills to operate in high-pressure conditions because in a single day a Forensic Toxicologist receive a lot of cases and there is a responsibility to test all those samples in the given period of time.
There are different tests and instruments available to detect and determine the dose of a poison, drug or alcohol. Apart from being skilful, a Forensic Toxicologist must be healthy and strong as sometimes, he/she may have to be present in difficult conditions in front of decayed, foul, nasty kind of smells and may have to stand for long times which could be very distressing.
Above all, a Forensic Toxicologist must be confident as he/she are expert witnesses of the case and may have to testify in the court in front of a magistrate and explain his testimony in the best possible and easy way that the court is able to understand his opinion regarding the case.
Case study of Forensic Toxicology
In 1878 May, Reverend George Vosburgh a young pastor in the city of Jersey was arrested on charges of poisoning his wife named Harriet. He was alleged to have been giving her overdoses of tartar emetic.
In the winter, of 1877-78 their marriage was failing because Mr Vosburgh was angry that his wife hadn’t given her any children. She had undergone two abortions without his consent and accepted a ring from a barperson and the quarrels between both of them started increasing.
Mrs Vosburgh suddenly fell ill which made her brother James suspicious that Mr Vosburgh might be serving her poison while attending to her needs on the bed. On the basis of the suspicion, James took samples of her sister’s servings given by Mr Vosburgh and her urine and took them to Bellevue Medical college’s chemistry laboratory.
In the tests conducted Antimony was found in every sample. Due to these results, a trial was set before the jury. During the trial, the professor brought his apparatus and performed various tests in the courtroom. Doremus’s demonstration on the witness stand was novel and impressive which was featured in newspapers. For some time, it seemed to shake the jury and the public.
However, the defence attacked the prosecution and called them disputed experts by attacking the chain of custody and constructing alternating events for what had occurred. James also wasn’t able to prove where his samples came from. Also, Mrs Vosburgh had recovered sitting beside her husband during the trial and refusing to testify.
The jury found Reverand not guilty. After his acquittal, Vosburgh resumed his work and separated from his wife. After a few months, additional evidence was brought in front of the press which indicated that he used to treat his wife badly and attempted poisoning. After all this, public support for him faded away and he was forced to resign from his post.