Takken van toxicologie:
Klinische = diagnose en therapie van vergiftigingen.Met klinische geneeskunde& klinisch-analytische chemie.
Forensische(juridische) = aan de hand van chemich-toxische bevindingen worden uitspraken gedaan in juridische zaken mbt.misbruik en verwaarlozing van gifstoffen
Occupational = Geeft adviesen mbt maximale blootstelling aan gifstoffen op het werkplek. Betrokken in biological monitoring. Dit houdt in dat interne blootstelling van de werknemers systematisch gemeten wordt .
Food toxicology = onderzoek en advisering over chemische stoffen in het voedsel. O.a Additieven.
Environmental = effects on populations & eco-systhems.
Risk = the probability that the adverse effect will occur.
Hazard = a potential danger of a compound or a process.
Risk Assesment = integrating hazard characteristics with actual exposure levels(exposure assesment). Evaluation of the health and environmental risks of chemicals.
Risk management = integrating risk assesment with social , economic and political aspects.
Hazard Indentification – Hazard characterisation - Risk assesment – Risk management.
Qualitative principles describing nature of the effect:
local effects = occur at the site of first contact. Produces by ingestion or inhalation.
Systemic effects = deleriant effects at a distant site due to absorbtion & distribution.
Target organs = where the major toxicity occurs. Often affected: CNS.
Bloed-lever-niern- longen-huid.
Spieren en botten zijn minst vaak aangetast als systemisch effect.
Primary lesion = reaction at molecular level. Symptomen van de vergiftiging zijn het resultaat van deze reacties.
Receptors = molecular structures affected by the substances.
Electrofiele agenten = reageren met alle nucleophiele groepen.DNA kan optreden als een toxicologische receptor.
Reversible/ irreversible = vermogen om te regenereren bepaalt dit. Carcinogene&teratogene effecten zijn niet omkeerbaar.
Variation in toxic response INTER-(between) species: lichaamsafmetingen,verschil in fysiologie, metabolisme toxine kan varieeren.
Variation in toxic response INTRA -(tussen) species: genetische polymorfismes, leeftijd, voeding&lifestyle, ziekses, gender.
Quantitative principles:derempelwaardes - tresholds
ED50=Mediaan effectieve dose. Afgeleid door interpolatie.
LD50=Statistisch afgeleide single-dose van de stof that can be expected to cause death in 50% of the animals tested.
NOAEL= No Observed Adverse Effect Level
LOAEL= Lowest Observed Adverse Effect Level
Algemene begrippen:
dose-response curve = illustrates dose-effect relationship. Respons of a population of organisms to a Toxic substance is more or less normally distributed in relation to the logarithm of the dose.
acute toxicity = exposure to a chemical for less than 24h
sub-acute = repeated exposure for 1 mnth or less.
Sub-chronic = 1-3 mths
chronic toxicity = more than 3 mnths
carcinogen = inducing cancer.
addition= if proportional summation of effects occurs.
Synergism/potentiation = if combined effect is stronger, then to be expected on the separate effects.
Antagonism/depotentiation = attenuation of the effect.
Haber's rule = effects of toxins depend on the product of concentration and the duration of exposure. Concentration- time curve.