The study of the adverse effects that chemicals, physical agents, or biological substances have on living organisms is what we call toxicology. It is a multidisciplinary field that blends biology, chemistry, and medicine to protect public health and the environment.
Here are 10 fascinating facts about the “science of safety”:
- The Dose Makes the Poison: Coined by Paracelsus, the ‘Father of Toxicology’, this principle states that every substance is a poison if the dose is high enough. Even water can be lethal (water intoxication) if consumed in excessive quantities.
- Etymology of the Word: The term ‘toxicology’ originates from the ancient Greek word toxikon, referring to the poison used on arrows.
- Botulinum Toxin: Produced by the bacterium Clostridium botulinum, this is the most acutely lethal substance known. Yet, in minute, controlled doses, it is used medically and cosmetically as Botox.
- The King of Poisons: Arsenic earned this title because it was historically favoured by assassins. It is odourless and tasteless, and until the 19th century, its symptoms were often mistaken for natural illnesses like cholera.
- Mithridatism: Named after King Mithridates VI, who lived in fear of assassination, this is the practice of protecting oneself against a poison by gradually self-administering non-lethal amounts to build immunity.
- Forensic Origins: Matthieu Orfila, a Spanish physician, established the first systematic correlation between the chemical properties of poisons and the biological damage they cause, allowing toxicology to be used as evidence in court.
- The LD50 Scale: To measure toxicity, scientists use the ‘Lethal Dose 50%’ (LD50), which is the amount of a substance required to kill half the members of a tested population. However this is a very blunt tool, and the results are not truly reliable between species. For instance if we would have tested dogs for the toxicity of chocolate, the world would have been a less happy place to live in.
- Bioaccumulation: Some toxins, like mercury in fish, do not leave the body easily. They build up in the tissues of organisms over time—a process studied by the famous Leonardo da Vinci, for instance.
- The Silent Killer: Carbon monoxide is a common household toxicant. Because it is colourless, odourless, and tasteless, it is often undetected without a dedicated alarm.
- Individual Susceptibility: Toxicity is not universal. Factors like age, genetics, and even the time of day can change how a person’s body metabolises a toxin.