environmental toxicology exam 1 material

definition of anthropogenic

human origin, doesnt exist in nature

Difference between pollutant and contaminant

pollutant: came from human, not natural - PFAS from teflon coatings

contaminant: came from nature, naturally occuring - lead and cadmium residue in chocolate

what is a biomarker

biological response to a toxic compound

• mark of toxic event in organism

what is a xenobiotic

anthropogenic products, do not play a functional biochemical role

what is an individual in an ecosystem

1 organism of 1 species

what is a population in an ecosystem

all members of a specific species

what is a community in an ecosystem

multiple populations in one space

what is abiotic environment

a non living component of any environment

affects organisms

what is a biotic environment

organisms in populations and communities

organisms affect

what are abiotic factors

climate

• temperature, precipitation

elements

• stoichiometry of C/N/P

• nutrients

geology

• near water/desert?

• sandstone? slate?

whaat are ecosystem processes

the physical, chemical, and biological actions or events that link organisms and their environment

1) production

2) decomposition

3) cycling and fluxes

4) resilience

what is primary production

deals with autotrophs who make their own food

what is gross primary production

total plant biomass created in a given time period, usually a year

what is net primary production

total plant biomass created iin a given time period, minus what is consumed by heterotrophs (snails, cows, squirrels)

what is secondary production

biomass made by heterotrophs

• how much did the organism grow from consumption?

what are cycles and fluxes

stoichiometry (ratio)

sources: more of something

sinks: less of something

• tree= source, organisms= sink

what is recalcitrant mobility

not bioavailable.

either currently in use by an organism or locked in a difficult form

what is labile mobility

bioavailable

either a loose molecule in the environment (soil,water,air)

or a discarded organismal unit (feces,cropse)

what is transformation mobility

coversion of one from to another (nitrogen cycle)

what is resilience

niche redundancy

how many different organisms occupy the same functional niche

what are ecosystem services

many and varied benefits that humans freely gain from the natural environment and from properly functioning ecosystems

• supporting, provisioning, regulating, cultural

what are supporting ecosystem services

basal functions (foundational functions) on which all others depend

without supporting ecosystem services none of the other ones can occur

what are regulating ecosystem services

benefits obtained from regulation of ecosystem processes

indirect benefits humans do not put extra effort into

• pollination, carbon sequestration, purification of water and air

what are provisioning ecosystem services

involved human labor, put effort into obtaining

tangible prodcuts that humans obtain from ecosystems

• food, raw materials, genetic resources, medicinal, energy

what are cultural ecosystem services

nonmaterial benefits people obtain from ecosystems

• cultural (books, painting), spritual and historical, recreational experiences

what are ecosystem functions/services

functions: processes

services: what we get from them

what are lipophillic (hydrophobic) molecules

fat loving molecules

• non polar

• larger

• lots of carbons

what are lipophobic (hydrophilic)

fat fearing molecules

• polar

• smaller

• less carbons, more NOS

charcateristics of metal ions

1) good conductor of electricity

2)present on earth since its formation (not anthropogenic)

3) often enter ecotox world through mining activities

4) form cov bonds and can transfer electrons

what is a anthropogenic enrichment factor

described the level of human contribution

why are metals non biodegradable

theyre able to move freely from association to association

they differ in toxicity

what is eutrophication

over enrichment of nutrients in environments

• lots of algae

  • when algae dies —> pulls O2 from H2O

  • causes fish to die —> pulls more O2

what enzyme changes Fe3+ back to Fe2+ after O2 leaves

methemoglobin reductase

what does nitrate (NO3) break down to in the body and why is it bad

breaks down to nitrite (NO2)

• “stickier” to hemoglobin

• NO2 keeps the heme as Fe3+

• cant be reduced and can’t pick up more O2

  • why babies turn blue

how can you come across extra NO2 in your body

• extrememly rural areas that rely on well water

• crops rely on fertilizer (N/P heavy)

  • runs into ground, well water is ground water

  • nitrate interferes withe hemoglobin

what are greenhouse gases and why are thye bad?

CO2, CH4, O3, CFC (chloroflurocarbons)

• O3, CFC lead to destruction of atmosphere

• leads to global warming, ozone destruction, smog, ocean acidification

what are the main air pollutants and where do they come from

• NOx, SOx

• come from fossil fuel and gas emissions

  • gas stove —> higher level of NOx and SOx in the house

  • 
    

• Acid rain —> aquatic and soil degragation

  • nitric and sulfuric acid

what are types of pesticides

• herbicide

• insecticide

• rodenticide

what are types of industrial processes

• direct use

• waste/byproduct

• safety

what are organochlorides

organic molecules containing chlorine

• chlordane, aldrin, dieldrin

  • aldrin and dieldrin use Na+ channels in neurons

what are cyclodienes

• classic organochlorines

• lipphilic

• persistent, dont break down easily

• very neurotoxic, but we dont know the mechanism to it

what is the structure of dis molecule

chlordane

what is the structure of dis molecule

aldrin

what is the structure of dis molecule

dieldrin

what are polychlorophenols

chlorine + wood phenols

acidic

water soluble

chemically reactive

what are polychlorinated biphenyls (PCBS)

two phenyls with many chlorines

they are anthropogenic

bioaccumulate in tissues due to the lipophilic abilities of them

what is DDT

dichloro diphenyl trichloroethane

doesnt break down very well metabolically

banned in 1972

what do organophosphorus do

stop enzymes nerve signals

inhibity acetylcholinesterase

neurotoxic

volatile and lipophilic (can bioaccumulate in tissues)

short lived in environement

non systemic - dont travel very far in body

if you survive can metabolically break down

what are carbamates

derived from carbamic acid

inhibit acetylcholinesterase

lipophobic-ish (depends on R-groups)

typically used to target mollusks and insects

what are pyrethroids

non-anthropogenic derived from mums

inhibit insect muscle action

photodegraded - if deep in soil can persist for some time

generally not toxic to humans (very toxic to cats)

usually used for vector insects

mosquitos and ticks are growing resistance

what are neonicotinoids

can be sprayed

compete with acetylcholine for receptor - neurotoxic

somewhat polar, some lipophilia

insects more sensitive that vertebrates

usually used as an insecticide for biting and sucking insects that attack plants

systemic - applied one place but incorporated throughout

what are phenoxy herbicides

share same pathway as plant growth signals

lipophilic

control dicot (eg.soy) weeds in monocot (eg.corn)

mimics growth hormone auxin - dicots grow to death

• agent orange

  • mutagen, apoptosis trigger

  • used in vietnam to get rid of jungle

what are phenoxy herbicides

DEET (diethyltouluamide)

original use was a pesticide

topical repellent

targets insect olfactry neuron receptors

• mosquitos are attracted to CO2 and butric acid, DEET makes these scents unrecognizable

low rate of bioaccumulation

toxic for river fish and zooplankton

why is white nose syndrome in bats bad?

invasive cold loving fungus species

• fewer bats —> more insect pests —> higher pesticide use —> higher infant mortality

what are rodenticides

blood thinner and rat poison

antagonist to vitamin K

many rats have resistance

accumulate in liver

also biomagnified harming birds who eat rats

what are the three main types of rodenticides

bromadiolone

• anticoagulant

• super warfarin, internal hemorrhaging

diphacinone

• anticoagulant

• longer active half-life than warfarin

bromethalin

• not an anticoagulant

• lowers ATP synthesis and shuts down Na/K pump

• leads to a buildup of CSF, causing high intracranial pressure

  • damaged neurons, causes paralysis, convulsions, and death

    

what are detergents

typically act as surfactant

either polar or totally nonpolar

form micelles around nonpolar or polar substances

can use internally to get drugs into cells

can be endocrine disruptors

• binds to a hormone receptor but doeesnt inhibit the response

• can also mimic hormones to over produce a response

  

what are PFAS

per or polyfluoroalkyl substances

• synthetic organo-fluoride chemical compounds that have multiple fluorine atoms attached to an alkyl chain

• CnH2n+1

• should have atleast one fully fluorinated methyl group

large family of chemical compounds that dont break down in environment

resistance to heat oil and water

most common PFAS

1) PFOS - perfluorooctanesulfonic acid

• firefighting foam, fabric treatments, semiconductors

• problematic

2) PFOA - perfluorooctanoic acid

• firefighting foam, surfactant (forms micelles), insulation, waxed surfaces

when does a pollutant become toxic

when a threshold is exceeded

how can substances be transported in the ATMOSPHERE

as gases or particles

• ozone, smog, fossil fuels, CFC, Diesel fuel

what are greenhouse gases

gasses from fossil fuels

CO2 from combustion

cows emit lots of methane

• methane is better at trapping heat in the atmosphere

acid rain!!!! NOx and SOx

what are ozone and smog

come from fossil fuel emissions, smoke, and particulates

how is ozone formed

CO2 and NOx are ionized by sunlight

why is ozone bad in the troposphere

aggravates asthma allergies and lung irritation

why are chlorofluorocarbons present in the stratosphere

they were used in fridges freexers and air conditioners

ended up concentrated over the south and broke a hole into the atmosphere

montreal protocol 1987

why is diesel fuel bad for the atmosphere

has many metals

• antimony, chromium, cobalt, selenium, mercury, lead

along with other compounds

• sulfur, dioxins, cyanide, polycyclic organics

what are the health effects diesel fuel poses

cancer, heart and lung disease, mental function, headache, dizziness, nausea, coughing, tightness of chest

how are pollutants transported in the terrestrial

• landfills, fertilizer, chemical sprays

wash down to waterbodies

aerosolized back into the air

how are metals polluting the terestrial

mining activities

• smelting, high conc, acid waste (gold extraction)

Burning fuel

• sulfur and metal dispersal (diesel trucks)

Ecosystem effects

• soils, biodiversity

mitigation and rehabilitation

• spreading sewage, filtering emissions, change compostion (gasoline, birdshot), soil remediation

how much of freshwater are rivers, lakes, and wetlands

0.8%

what is residence time

how long water stays in a comparment

how much of freshwater is frozen

87.2%

how much of freshwater is ground water

12%

used for drinking water and irrigation

what does size as discharge mean

volume of water passing through a point in a period of time

what does oligotrophic mean

low in nutrients

fewer species

generally younger colder and deeper

what does eutrophic mean

high in nutrients

more species

generally older warmer and shallow

what does eutrophication mean

process by which addition of nutrients takes ecosystem past stable points

• oligotrophic —> eutrophic

what is mesotropic

moderate levels of nutrients

moderate levels of species

moderately older, warmer and shallower

what is a point source

single thing/event that you are able to point to

• discharge pollution from a specific location/structure

  • drain pipes, ditches, sewer output

what is a nonpoint source

multiple things/events that you cannot point to

• diffuse, non specific source of pollution

  • fields. lawns, golf courses, highways (the cars)

harder to regulate - more sources

what does organic pollution include

pathogens and waste

pesticides and industrial substanes

what is biological oxygen demand

the amount of dissolved oxygen consumed by aquatic organisms

• sewage inputs spike biological oxygen demand and decrease available dissolved O2

what do aerobic organisms require

require oxygen

what do inorganic pollutants include

metals, salts, and acids

where do acids and bases come from

byproduct of industrial processes and mining

acid rain deposition

where do salts come from

result of a neutralization reaction

excess road salt

• cause developmental problems in people and kill wildlife

details of Gold King Mine

opened in 1887, closed in 1923

exposed metal sulfide minerals such a pyrite to water and air

• created sulfuric acid soup

in 2014, AMD began draining

in 2015 landslide buried pipes, uncovering led to repture of the pipes

• happened for days on end

how can organic chemicals get into the earth

improper disposal of industrial and household wastes

pesticide runoff from farms fields roadsides golf courses lawns (non point)

what is sediment

natura;, carries nutrients in the water, makes fertile soil on shore

what can sediment be bad

internal shading, abrasive (scores algae and invertebrates), prevents fish nesting, clogs industrial equipment

what is thermal pollution

effulent from industrial cooling structures (data centers)

decreases dissolved O2, can kill aquatic life

think of it like a fever in humans - too hot —> death

Jackson MS no water example

predominantly POC town

reduced tax base, prompted slow decline of city services

• lead pipes, bad pressure, many failures

2022 crisis

• Jul 29, boil water advisory following rain/flooding

• Aug 27, storm flooding causes pumps to fail - no water

• Sep 10, water pumps restored, boil water advisory still in place

how can directional currents play a role in transporting pollutants in aquatics

• dead zones, algal blooms, toxic chemicals, heavy metals, oil, sediment, garbage

directional currents can sweep these all up and take them from place to place

how does ocean acidification play a role in transporting pollutants in aquatics

• excess CO2 shifts Ca(CO3)2 towards acid dissociation preventing Ca(CO3)2 formation

happens due to CO2

seaweed can help with this in colder places!

what is a partition coefficient

measure of the differnce in solubility of the compound between two phases

what does Log Kow provide

index of hydrophobicity

• conc. in octanol/conc. in water

what does a Log Kow of 1 mean

equal concentrations in octanol and water

what does a Log Kow of less than 1 mean

its lipophobic

• the higher concentration will be in water

what does a Log Kow of greater than 1 mean

its lipophillic

• higher concentration will be in octanol