Pharmaceutical Toxicology is a discipline, overlapping with biology, chemistry, pharmacology, medicine, and nursing that involve the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating exposures to toxins and toxicants. The relationship between dose and its effects on the exposed organism is of high significance in toxicology. Factors that influence chemical toxicity includes the dosage (and whether it is acute or chronic), route of exposure, species, age, sex, and environment. The Toxicologists are experts on poisons and poisoning.