Environmental toxicology
What is NOAEL ?
No Observed Adverse Effects Levels
What is ADI and how can we calculate it?
Acceptable Daily Intake. ADI = (NOAEL / uncertainty factor) x (safety factor)
What is EDI and how to calculate?
Estimated daily intake. EDI = Intake of one type of food x [chemical in that food]
Which one should be higher and why? ADI or EDI?
ADI higher because you have to eat less or equal to acceptable daily intake
What is a toxic substance?
is a substance that causes an adverse effect when is administrated to an organism at a *given dose* ! dose makes the poison
Tell me which chemicals arr synthesised by humans and those of natural origin.
humans: pesticides and industrial app (PCBs)
natural: biotoxins, geographical sources (lead from shot)
What is ED50 and LD50?
they refer to a dose-response relationship. ED50 is the concentration for 59% of population showing effects and LD50 is the necessary comcentration for having 50% of dead population.
what is bioaccumulation?
when harmful substances (pesticides, metals..) build up in the body of living organism over time. Absorbed faster than excreted out of the body.
what is biomagnification?
harmful substances become more concentrated as it moves up the food chain
Tell me things about DDT
is an organoclhorine insecticide that persist in environment and in the body for a long time (long half life). It helped to stop hunger by killing insects and increase crop productivity but it's harmful for animals. It's banned