Chronic Poisoning

The chemical environment was recognized as a threat to health early in history. Well-documented outbreaks of occupational mercury and lead "poisonings" had been recorded and preventive measures implemented by 200 BC. In the Middle Ages, arsenic poisoning was used as a political weapon. In more recent times, industrial toxins, "accidental poisoning" in childhood, purposeful overdoses in adults, adverse reactions to drugs, medication mix-ups in hospitals, and environmental hazards increasingly have been recognized. The patient's metabolic and genetic variability determine the impact of a given molecule in hereditary disorders such as phenylketonuria, glucose-6-phosphate dehydrogenase deficiency, and others.