Class Notes (836,052)
Canada (509,597)
EESA10H3 (506)
Lecture 9

EESA Notes Lecture 9

5 Pages
Unlock Document

Environmental Science
Jovan Stefanovic

Lecture 9ToxicologyDefinition o Study of poisons o the science which studies toxic substances or poisons that are substance which cause alteration or perturbation in the function of an organisms leading to harmful effects Truhaut 1974How harmful a substance is depends on the chemical characteristics of the substances o Some characteristics to consider areElectronegativityPolarityOxidation StateMolecular WeightDissociationSolubilitywater soluble toxins hard to enter human cells and fat soluble toxins can easily enter the human cell and bioaccumulateAssessing Chemical Hazards o Persistence of the chemical do they break down or remain in the same chemical configuration eg DDT o Bioaccumulation o Biomagnification o Chemical interactionAntagonistic effects two different chemicals taken up by the same given individuals and behave antagonistic towards each other however they are very toxic if taken up separately One chemical reduces the toxicity of the other if mixed or existing together For example Vitamins A and E may decrease chemical toxins that may induce cancerSynergistic effects one chemical enhances the toxicity of the other chemical present For example exposure to asbestos can lead to lung cancer by 20fold However smoking in the presence of asbestos increases the risk of lung cancer by 400foldo Multiple chemicalsfood additives pesticides air pollutioncomplicates the risk of getting harmed and diseased even more o When studying toxicology it is important to determine three thingsWho the receptor isAny organism that receives exposures to toxinsTo study the receptor we must understand the frequency of the exposure that person has undergoneAge is important ie a child elder are more vulnerableGeneral healthGenetic makeupWhat dose they receivedAmount of chemical a person takes upIngested greatest source of exposure85Inhalation air pollutants particles and volatiles 10Absorbed through the skin industrial 5
More Less

Related notes for EESA10H3

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.