Quantitative study of adverse effects of chemicals on living systems: dose–response, mechanisms of injury, xenobiotic metabolism, risk assessment. Substrate of regulatory science (EPA, EFSA, FDA safety files).
toxicology
Dose–response curve
Relation between administered dose and biological effect; typically sigmoidal E = E_max · C^n/(EC₅₀^n + C^n) (Hill).…
LD₅₀ / LC₅₀
Dose (or environmental concentration) killing 50% of a test population. Standard (if blunt) acute-toxicity ranking: LD₅₀ < 5 mg/kg…
Xenobiotic metabolism
Phase I oxidation/reduction/hydrolysis (CYP450 family) introduces polar groups; Phase II conjugation with glucuronide, sulfate, GSH,…
Carcinogen
Agent causing or promoting cancer. IARC 1 (known human: benzene, asbestos, formaldehyde), 2A (probable), 2B (possible), 3 (inadequate), 4…
Endocrine disruptor
Chemical interfering with hormone signalling (agonist, antagonist, biosynthesis/clearance modulator). BPA, phthalates, PCBs, PFAS.…
Hepatotoxicity
Liver injury from intrinsic (dose-dependent, predictable: acetaminophen) or idiosyncratic (host-dependent, unpredictable: flucloxacillin)…
NOAEL / benchmark dose
Highest tested dose producing no statistically or biologically significant adverse effect (NOAEL). Modern refinement: benchmark-dose BMD,…
Risk assessment framework
Four-step NRC (1983): hazard identification, dose–response assessment, exposure assessment, risk characterisation. Produces margin of…