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some parts of the endocrine system?
thyroid, pituitary gland, pancreas, ovary, testes
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EDCs
endocrine disrupting compounds
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Two different classifications of EDCs?
those that occur naturally, and those that occur synthetically
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EDCs exert their effects by...
- 1. mimicking or antagonizing the effects of hormones
- 2. altering the pattern of synthesis + metabolism of hormones
- 3. modifying hormone receptor levels
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Endocrine disruption?
EDCs indirectly interact with the endocrine systems that control bodily functions, resulting in excessive amounts or suppression of hormones
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Number of chemicals/heavy metals that are reported of having endocrine disrupting actions?
~38 000
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Number of chemicals that according to the ESEPA need to be tested to see if they effect the endocrine system?
87 000
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3 kinds of potential endocrine disrupting pharmaceuticals?
- steroidal pharmaceutical substances
- personal care products
- nonsteroidal pharmaceutical substances
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Atrazine
herbicide, also a potent endocrine disrupter that's active at low ecologically relevent concentrations
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BPA
bisphenol A, the substance that leaked out of the rat cages in that lab, caused abmormalities in chromosomes/meiosis
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Pollutants ______ song complexity and the _____ of the brain area HVC in a songbird
increase, volume
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Lake that suffered a major spill of which pesticides in 1980?
- Lake Apopka (Florida), dicofol and DDT
- - had affects on alligators
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tributylin (TBT)
- component of anti-fouling paints
- - causes "imposex" in a range of male gastropods
- - endocrine disruption believed to involve suppression of enzyme aromatase (converts androgens to estrogens)
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imposex
conditions in which male sex organs (penis and vans deferens) are superimposed in a female gastropod, effectively preventing the animal from reproducing
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Feminization
- domestic and industrial effluents may cause feminization in fish
- - incl. high levels of vitellogenin in blood of male fish
- - occurance of oocytes in testes of presumed male fish
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Vitellogenin
a protein synthesized in blood of male fish under estrogenic stimulation and secreted into the blood stream for incorporation, as the precursor for some of the yolk proteins, into developing oocytes
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Seems that the most pervasive estrogens in the aquatic environment are _________________
steroids derived from human excretion
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Intersex
condition where an individual is intermediate in sexual characteristics b/w a normal male and a normal female
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Intersex fish: chronic exposure of fish to very low concentrations of the __________________ stimulated vitellogenesis, also sex reversals in males to phenotypic females
synthetic steroid ethinyl estradiol (1.5ng/L)
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exposure to low concentrations of the androgenic steroid __________ has a masculinizing effect _____________
methyltestosterone, (suppression of vitellogenesis, sex reversal of female to males)
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17a-ethinylestradiol (EE2)
- used in birth control pills
- found downstream of sewage treatment plants
- more persistent than other estrogens
- induces vitellogenin production in male fish at low ng/L
- acutely toxic to aquatic organisms at mg/L
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Symptoms of male and female fish from ELA when EE2 added to lake?
- Males: display intersex, primary-stage oocytes among remnants of testicular tissue
- Females: ovaries had atretic follicles
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Minamata Disease?
- Chisso Corporation Factory in Minamata, Japan
- opened in 1932
- pumped 500 tons of effluent per hour into Minamata Bay
- people ate the fish out of the bay, got mercury poisoning aka "Minamata Disease"
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two biggest industries that contribute to atmospheric mercury?
coal burning, gold mining (in poor regions mercury still used for gold panning, gold sticks to the mercury)
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Three basic forms of mercury:
- 1. Hg(0)
- 2. Hg(II)
- 3. MeHg
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Hg(0)
- Elemental mercury, most prominent in atmosphere
- reduced form, quite volatile (can be gaseous)
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Hg(II)
- Ionic mercury, oxidized
- comes out of atmosphere in rain
- primarily found in plants, soils, lakes
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MeHg
Methylmercury, bioaccumulates and biomagnifies
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2 basic mercury processes of importance
- 1. microbial methylation of Hg(II) to methylmercury
- - done primarily by sulphate-reducing bacteria in anaerobic environments like lake sediments or saturated wetland peat
- 2. photoreduction of Hg(II) or methylmercury into Hg(0)
- - sort of a good process, done primarily by UV radiation
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Marketing limits for Hg consumption advisories
Canada: 0.5ppm Hg (or 0.5 micrograms Hg per g food)
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Recommended daily intake level of Hg for pregnant women or children under 12?
0.2 micrograms per kg of bodyweight
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consumption of __________ is the primary route of methylmercury exposure in humans
contaminated fish
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METAALICUS
Mercury Experiment to Assess Atmospheric Loading in Canada and the US
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spike mercury
all the mercury experimentally loaded onto the watershed, including the isotope and its impurities
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ambient mercury
all mercury that is not spike mercury
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Half-life (in days) of mercury on forest canopy vegetation
- Conifer: 183 days
- Deciduous: 108 days (shorter bc leaves break down more readily)
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demethylation
destruction of methylmercury
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Climate phenomenons that have a low confidence that there is a human contribution to observed changes?
Intensity and/or duration of drought, increase of tropical cyclone activity
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General trend of changes in annual precipitation over land
wet areas getting wetter, dry areas getting drier
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Trends: Northern hemisphere spring snow cover..
declining
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Trends: arctic summer sea ice extent..
declining
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Trends: change in global average upper ocean heat content..
increasing/warming
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Trends: global average sea level change..
rising, due to thermoexpansion of water and melting glaciers/icecaps
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Trends: surface ocean CO2 and pH..
- CO2 rising, pH lowering
- - as atmospheric CO2 increases, it diffuses into the ocean and ocean CO2 levels rise, then the ocean becomes more acidic
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Radiative forcing (RF)
- measurement of the capacity of a gas or other forcing agents to affect that energy balance, thereby contributing to climate change
- - shows how different chemicals/things we know affect climate change are changing the radiative forcing of the earth
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Main radiative forcing agents:
- Well-mixed greenhouse gases
- - CO2
- - CH4
- - halocarbons
- -N2O
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Aerosols and precursors
- mineral dust, sulphate, nitrate, organic carbon, black carbon
- do negative radiative forcing
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Three large-scale indicators of climate change in the atmosphere, cryosphere, and ocean
- 1. change in continental land surface air temps
- 2. Arctic and Antarctic September sea ice extent
- 3. Upper Ocean heat content in the major ocean basins
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in the IPCC report, difference between RCP2.6 and RCP8.5
RCP2.6 means human activity levels if we "get our act together", RCP8.5 represents if we continue with business as usual
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Climate change drivers
- natural fluctuations in solar output (SWR)
- aerosols (SWR)
- clouds (SWR, LWR)
- ozone (SWR, LWR)
- greenhouse gases and large aerosols (LWR)
- surface albedo changes (SWR)
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a light surface albedo of ice and snow will _________
reflect light away
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surfaces with a dark albedo like the ocean will ___________
absorb heat and light
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_________, the active weather layer of the atmosphere, is _________
troposphere, warming
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more than ____ of the excess energy absorbed by the climate system has been stored in the _______
90%, oceans
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Main contributors to rising sea levels
- thermoexpansion of water
- melting glaciers and icesheets
- changes in storage and usage of water on land
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salt water has a _______ heat capacity than fresh water
lower, so the higher the salinity of the water, the faster it will warm
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atmosphere can hold ____ more water vapour for each _________ of warming
- 7%, degree celcius
- therefore the warmer the air, the moister
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Increased CO2 levels in the ocean means:
- acidified ocean
- shifts the bicarbonate cycle
- decreases pH over time
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Bicarbonate cycle
when atmospheric CO2 exchanges across the air-sea interface, it reacts w/ seawater through a series of 4 chemical reactions that increase the concentrations of the carbon species: dissolved carbon dioxide, carbonic acid (H2CO3), and bicarbonate (HCO3-)
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The 4 reactions in the bicarbonate cycle:
- CO2 <-> CO2
- CO2 + H2O <-> H2CO3
- H2CO3 <-> H+ + HCO3-
- HCO3- <-> H+ + CO3-
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Time series of changes in large-scale ocean climate properties? (4)
- - carbon (increasing)
- - global mean sea level (increasing)
- - upper ocean heat content (increasing)
- - high salinity minus low salinity (increasing)
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in the past _____, ________ trend of average annual extent of sea ice in the arctic of ________
34 years, downward, 3.8% per decade
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______ shows ____ of _____ per decade of average annual extent of sea ice
Antarctic, decrease, 1.5%
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Equilibrium line altitude (ELA)
- for a given climate, the ELA has a specific altitude (ELA1), due to temperature increases ELA shifts to a new altitude (ELA2)
- after the glaciers readjust to the new ELA, some glaciers have shrunk and some have completely disappeared
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Changes in the cryosphere: frozen ground
increasing permafrost temps up to 2°C, increase in active layer thickness
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changes in the cryosphere: snow cover
decreases throughout the year, largest decreases (53%) in June
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changes in the cryosphere: lake and river ice
- contracting winter ice duration, delays in autumn freezeup
- - evidence of recent acceleration of both across the NH
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changes in the cryosphere: glaciers
melting to glaciers major contributer to sea level rising
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changes in the cryosphere: sea ice
- arctic sea ice extent declines at rate of 3.8% per decade
- extent of thick multiyear ice in arctic declined at rate of 13.5%/decade
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changes in the cryosphere: ice shelves and ice tongues
continuing collapse and retreat of ice shelves along Antarctic peninsula
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changes in the cryosphere: ice sheets
Greenland and Antarctic ice sheets lost mass and contributed to sea level change over the last 20 yrs
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main natural processes that remove CO2 from the atmosphere:
- Land uptake (photosynthesis- respiration)
- ocean invasion: seawater buffer
- reaction w/ calcium carbonate
- silicate weathering
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lots of nitrogen produced through the making of ________
fertilizer (Haber Bosch process)
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What happens to CO2 after its emitted into the atmosphere?
- rapidly distributed b/w atmosphere, upper ocean, and vegetation
- carbon continues to be moved b/w the different reserviors of the global carbon cycle (soils, deeper ocean, rocks)
- depending on how much CO2 is released, bw 15% and 40% will remain in the atmosphere for up to 2000yrs
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Scattering aerosols:
cooling
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Absorbing aerosols:
warming
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_____ can act as _______ upon which liquid droplets form
aerosols, cloud-condensing nuclei
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Contribution of water vapour to the greenhouse effect relative to that of CO2 considered to be __________
2 to 3 times greater
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Black carbon
from fossil fuels and biofuels, if you deposit it on snow packs it changes the albedo really quickly so there's more melting going on compared to if there were no emissions of black carbon
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Big 3 RF'ers
CO2, CH4, halocarbons
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