The Science Of Poisons

Toxicology is ‘the scientific study of the characteristics and effects of poisons’ and incorporates the disciplines of pharmacology, molecular biology and genetics. Paracelsus (1493-1541), a true pioneer of toxicology and medicine, described the main underlying principle of toxicology as, ‘All things are poison, and nothing is without poison – only the dose permits something not to be poisonous’. Unlike many explanations from the 16th century, this one is still relevant today. For example, once described as the ‘poison of kings’, it is a well-known fact that arsenic is exceptionally toxic. Yet, it is also used to treat certain leukaemias.

There are several exciting jobs available in the field of toxicology, including drug discovery, forensic toxicology and environmental toxicology. Toxicology has evolved enormously since the 16th century to become part of the global billion dollar pharmaceutical industry, which has undoubtedly changed the world we live in today. Unbelievably, it is estimated that a new drug will cost 1 billion dollars to develop from start to finish. But in an industry with an annual turnover of 600 billion dollars per annum, this is loose change.

The police rely heavily on the expert advice of toxicologists in a multitude of important cases. Harold Shipman, perhaps one of the most prolific serial killers in history, is suspected of killing over 200 people in his time as a medical doctor. He murdered his victims with overdoses of heroin and was convicted using toxicological evidence. Furthermore, toxicologists specialising in risk assessment and environmental toxicology were at the forefront of the Irish pork dioxin crisis in 2008, which resulted in 100 million Euros worth of contaminated pork being destroyed before it entered our food chain.

Several groups in the School of Biology focus on this area of science, conducting research on chemicals such as pesticides, environmental pollutants and venoms. Mark Burton, a PhD student in toxicology, is studying the evolution of insecticide resistance in a number of agricultural pests and disease vector insects such as mosquitoes. With world population expected to exceed 9 billion people by 2050, there is an increasing demand for food. In order to comfortably sustain the growing population, a 50-70% increase in food production is required, but limiting factors, such as pest insects, account for a 15% overall loss in yield.

The most widely used insecticides are derived from chrysanthemum daisies and despite popular belief, are completely safe for human usage; in fact, it is the only insecticide that can be safely applied to mosquito bed nets. Unfortunately, insects are slowly becoming resistant to pesticides, which is why this area of research is so important to the future of food production and the human race. David Richards, an MRes student, is interested in extracting ladybird toxins to see how they affect humans. If you thought ladybirds were just harmless, colourful insects, you’re mistaken. Particularly for children, the risk of ingesting even common ladybirds could prove very dangerous. The toxins work by preventing neuronal signals from reaching their target, such as the lungs, leading to potentially a very unpleasant death. Very little toxicological study has been carried out in this area in the past, and this researcher hopes to show the world just how dangerous these insects can be.

For more information on toxicology-based postgraduate courses at the University, visit their website at

Richard Wall


Leave a Reply