Study Guides (238,098)
Canada (114,918)
Biology (1,063)
BIOL 354 (7)

BIOL 354 Midterm Review Notes

15 Pages
Unlock Document

University of Waterloo
BIOL 354
Vivian Dayeh

BIOL 354 Midterm Review NotesIntroToxicology study of harmful substances toxicantso Toxicant umbrella term for poisonous agent that produces harmful biological effects ex PAHs Toxin subset of toxicant harmful substance produced by an organism ex venom study of toxins is called toxinologyXenobiotic foreign substance to an organism can have positive or onegative effectsAnthropogenic caused or produced by humans describes unnatural ooriginFather of Toxicology Paracelsus o It is not the substance but the dose that makes the poisonEnvironmental ToxicologyEnvironmental toxicologyecotoxicology study of impacts of pollutants on oecosystems No exposureno effecto Toxicant must be released into environment Be exposed to target organism Be taken up by target organism Cause a response in target organism Environmental Toxicantso Radiation ex gamma radiation from nuclear plants Inorganic ex metalsmad hatters from mercury poisoning in hatmaking solutions Organic ex dioxins furanschimney sweeps had scrotal cancer because of PAHs in soot Pesticides ex insecticides Complex effluents liquid waste ex from minesHistorical need for ecotoxicologyo Changes in human behaviour shift from small communities to industrial civilization Pollution Paradigm shift the solution to pollution is dilution what is thrown away can come back to hurt youContaminants from Source to Receptor to ImpactContaminants move from high to low concentrationsoElements of a toxicity event ex snake biting a mouseo Generation of a contaminantno generation no problem Snake produces venom Release of contaminanttoxicant can be present but not released Snake holds venom therefore present until bite it is not released Movement of the contaminant to the receptorreceptorbiological organism Venom is released from fangs into bloodstream of mouseExposure at a high enough concentration for a long enough period of time Response Death Toxicants can enter environment from two sourceso Point source direct can see where it is entering from ex pipe into stream Nonpoint source indirect cant see where it is entering from ex auto exhaust ammonia run off from cow manureHaving exposure to a toxicant doesnt mean an organism will respond oDepends on Type of toxicant Type of organism Duration of exposureEx Warfarin is used as rat poison but also to help treat humans with blood clots The dose and the type of organism varies the response of the toxicantThe higher the dose the less time it takes to for a responseExposure routeso Oralmouth or dietdose Injectionintravenous subcutaneous intraperitonealTopicalonto surface of skinRespiratory inhalation via lungs or uptake via gillsconcentrationDose weight of toxicantweight of organismo units in Xgkg1 mgkg1 ppm 1 gkg1 ppbConcentration weight of toxicantvolume of air or watero units in XgL 1 mgL1 ppm 1 gL1 ppbBioassaysBioassays are used to measure toxicityo Determine the effects of a toxicant on an organism Lethality bioassay used to determine if chemical is toxic and how toxic it is relative to other chemicalsParts of a bioassayo Test organism Exposure timeDoseconcentration of the toxicantResponse based on degree of response death or no deatho Lethal results in death
More Less

Related notes for BIOL 354

Log In


Don't have an account?

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.