toxicitást

Toxicitást (Hungarian for toxicity, in the accusative form) refers to the harmful effects substances can have on living organisms. It is a central concept in toxicology, the study of adverse effects caused by chemicals, drugs, and other agents.

Toxic effects depend on dose, duration of exposure, route of exposure, and the characteristics of the organism. Key distinctions include acute toxicity, which results from short-term exposure, and chronic toxicity, which arises from longer-term exposure. Effects can be systemic or organ-specific, and may include damage to the liver, kidneys, nervous system, or other tissues. Some substances may be mutagenic, carcinogenic, or affect reproduction.

Measurements and endpoints are used to describe toxicity. Common metrics include LD50 (the dose that kills 50% of a test population), NOAEL (no observed adverse effect level), and LOAEL (lowest observed adverse effect level). Regulatory frameworks emphasize hazard identification, dose–response assessment, exposure assessment, and risk characterization to inform safety decisions.

Toxicokinetics and toxicodynamics describe how a substance moves through and acts in the body. Factors influencing toxicity include age, genetics, health status, nutrition, co-exposures, and interactions with other chemicals. Dose, timing, and individual susceptibility all shape outcomes.

Assessment and safety rely on classifications and regulatory guidance. Safety data sheets (SDS), hazard labeling, and regulatory agencies guide handling, exposure limits, and risk communication. Internationally, frameworks such as REACH in the European Union and similar programs in other regions govern chemical safety and risk management.

Examples of toxicitást concerns include industrial chemicals, pharmaceuticals, pesticides, and environmental pollutants. Ongoing research in toxicology uses computational models, high-throughput screening, and alternative testing methods to improve hazard prediction and reduce animal testing.