poison

Poison is a substance that can cause harm to living organisms when introduced, absorbed, or ingested in sufficient quantity. Toxic effects depend on the dose, duration of exposure, route of exposure, and the individual’s age, health, and genetics. Substances may be poisonous even at small amounts if exposure is repeated or if they act on sensitive organs.

Poisons can be chemical (such as heavy metals, pesticides, and solvents), biological toxins (like botulinum toxin or ricin), venoms from snakes or insects, or radiological materials. Exposure pathways include ingestion, inhalation, skin or eye contact, and injection. The dose–response relationship means higher doses generally produce more severe effects; many poisons also have thresholds or time-dependent toxicity. The LD50, the dose that kills 50% of a test population in acute exposure, is a traditional measure of toxicity.

Toxic effects vary by mechanism and target system. Some poisons interfere with cellular respiration or enzyme function, others disrupt the nervous, cardiovascular, or hepatic systems. The body’s detoxification processes, primarily in the liver and kidneys, can modify or neutralize toxins, sometimes creating harmful metabolites. In some cases, antidotes or specific medical interventions are available, while others require supportive care.

Medical management emphasizes preventing further exposure, decontamination when appropriate, and supportive care. Antidotes exist for certain substances, such as naloxone for opioids or specific antidotes for cholinergic poisonings and certain toxins. Poison control centers provide guidance, and treatment may involve monitoring for delayed effects.

Prevention and regulation focus on safe storage and labeling of toxic substances, workplace safety, environmental controls, and public education to reduce accidental and intentional poisonings.