toxicology UMN Midterm 2 Flashcards
How does mercury enter the food chain
bacteria converts it to organic mercury which bioaccumulates in the aquatic food chain
When the Minnesota Pollution Control Agency examined air pollution related health issues by the characteristics of Twin Cities zip codes, they found that health issues…
were more common in areas with higher proportions of BIPOC residents
T/F: measures to improve air quality have been detrimental to the US economy
FALSE
atrazine
chlorinated herbicide that is used to selectively control annual grasses and weeds before they emerge
who is the primary consumer of atrazine and what does it do for that country
The US - it boosts the largest economy in the world (for corn)
atrazine is the most common contaminant of what
ground, surface, drinking water
atrazine can be associated with tumors in what
rodents
pest
organisms that occur where they are not wanted or that cause damage to crops/humans/animals
pesticide
any substance intended for preventing, destroying, repelling or mitigating pests
where are pesticides applied
herbicides, fungicides, various substances to control pests
environmental toxicology
study of effects of environmental contaminants on organisms or ecosystems of concern
are all chemicals bad (if not list some that are good)
no. hydrogen and oxygen are vital for water and air
precautionary principle
when an activity raises threat to human heath, precautionary measures should be taken EVEN IF THERE IS A CAUSE AND EFFECT RELATIONSHIP THAT ISNT FULLY ESTABLISHED
biomagnification vs bioaccumulation
biomag - increase in pollutant concentration through the food chain (bottom of food chain to top)
bioacc - increase in pollutant concentration in one organism over a lifetime (left of food chain to right)
types of toxicants
carcinogens
mutagens
teratogens
neurotoxins
endocrine disruptors
allergens
what is carcinogens
substance that causes cancer
what is cancer
uncontrolled cell division
toxic definition
containing or being poisonous material especially when capable of causing death or serious debilitation of an organism
mutagens (and examples)
substance that causes change in genetic code. UV light, radiation, PAHs
Can a toxin fit into more than 1 class
Yes, some carcinogens can be mutagens and vise versa
over ___% of human cancers carry loss of function mutations
50
teratogen (and examples)
a substance that causes developmental deformities (alcohol, lead, warfarin, PAHs
what are PAHs
Polycyclic aromatic hydrocarbons: chemicals that occur naturally in oil, coal and gas
concept of critical window in teratogens
a period during development when an organisms phenotype is responsive to factors.Highly sensitive during the Embryonic Period
endocrine disruptor (and examples)
a chemical that affects endocrine signaling by mimicking hormones, interfering with hormone receptors or by changing the amount of hormone secreted (PCBs, pharmaceuticals, DDT, BPA)
what is DDT
synthetic organic compound used as in insecticide to persist in the environment and become concentrated in animals at the head of the food chain
what is the endocrine system
series of glands that secrete hormones that regulate many aspects of bodily function
Allergens (and examples)
Something that causes an allergic reaction affecting people different (Dander, pollen, sulphites)
case study: steps for assessing concern (5 steps)
- is the source reliable
- check references provided by the source
- what is/are the specific substances of concern and why
- check additional reputable sources (such as EPA, MPCA, non-profits, scientific lit)
- After checking what patterns do you find
Air Pollution
- Outdoor air pollution: particle pollution, ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides and lead
- Indoor air pollution
- Ozone layer
- Acid deposition
Clean air act of 1963
- addressed 6 critical air pollutants (particulate matter, ground level ozone, CO, SO, NO, lead), vehicle air pollution, acid rain, protecting strato ozone, regulating greenhouse gases
Acid deposition and Cap and Trade
- established Cap and Trade system for SO
- set limit for SO that could be emitted by power plants
- electric plants issued permits for allowance of emissions
Stratospheric ozone and air pollution
- CFC’s components of Freon
- used in aerosol cans
- very stable but in high UV become reactive in ozone
- hole in ozone layer formed
what did the montral protocol do
reduced CFC production by 95%
stratospheric ozone remained ___ and ozone hole slowly ____
stable, closed
every __ spent to reduce emissions from ____ results in ___ of benefits to _____
- $1 from mobile sources under the clean air act
- $9 to public health, the environment, productivity and consumer savings
air pollution is still the leading cause of what
death worldwide and in the US
acute vs chronic effect of containment
acute: one that occurs rapidly after exposure to a large amount of that substance
chronic: difficult to measure (alcohol, cigs, radiaiton exposure)
lethal doses
determined for substances from info gathering from records of homicides, poisonings and animal testing
lethal doe 50%
dose lethal to 50% animal testing
what are environmental contaminants
- contamination of items with harmful substances can affect anyone
- found in environment with higher amounts than natural
- exposed by residential, commercial, and industrial sources
common containments
arsenic, mercury, Bisphenol A, phthalates, lead, formaldehyde, radiation, radon
arsenic
naturally occuring element present through water, soil, air, dust, food (big problem in drinking water).
- can bind to soil and remain for years
bisphenol A
chemical synthesized in large quantitties for production of plastics and resins
- many applications
- source of exposure is diet
phthalates
chem used to soften and increase flexibility of plastic and vinyl
- used in hundreds of consumer products
exposure comes from water/food with plastic
lead
metal that occurs naturally in rocks/soil or burning in fossil fuels, has no taste/smell and us used in batteries, medical devices ect
- can harmfully affect every organ in your body and you can get lead poisoning
formaldehyde
colorless, flammable gas/liquid that has a pungent odor
- naturally produced in the body and is exposed by containing or breathing it
radiation
energy given off by atoms and is all around us
- exposed by soil, rocks and the sun
acid rain
when higher than normal amounts of nitric and sulfuric acid occurs in the atmosphere, the result is precipitation with pH lower than 5.6
what does acid rain result from
- natural sources like volcanoes and decaying vegatation
- man-made sources like emissions from SO or NO from fossil fuel combustion
impacts of acid rain
- leaching of soil nutrients that harm plants and soil
- release of substances toxic to trees and other plants
- corrosion of metals, paint, stone, cultural objects
- not being able to see
UV types (A B and C)
A: least energetic and harmful but can cause damage to living cells
B: most harmful form of radiation that reaches the surface
C: most harmful/energetic but does not make it to earths surface
primary and secondary air pollutants
primary: those released directly from the source into the air
secondary: produced through reactions between primary and normal compounds
PM (particulate material)
solid particles and liquid droplets made up of a variety of components that are suspended in the air.
- size is linked to potential for causing health problems
smog
mixture of air pollutants that form over urban areas as a result of fossil fuel combustion
two types of smog
industrial: produced by burning fossil fuels which produces co, carbon monoxides, sulfur and mercury
photochemical smog: formed when sunlight drives chem reactions
POPs - persistent organic pollutants
group of organic chemicals widely used as pesticides or chemicals that pose risk to human health and the ecosystem
3 ways they are produced and released by human activity
persistent: chems that last a long time in the environment. some may resist breakdown for years
bioaccumulative: can accumulate in animals and humans in fatty tissues and food they consume
toxic: can cause a wide range of effects in humans, wildlife and fishb
grasshopper effect
POPs make their way into the environment (wind, land, water, evaporation) on a daily basis through cycle of long-range air transport that
In the US, a primary solution to environmental mercury contamination is
reduction in coal burning for power generation
following the precautionary principle, should substances similar to BPA be approved
it should not be approved until safety has been well studied
where is atrazine found
found in runoff water from fields, ground water, rivers and well water
what does atrazine interfere with
electron transport in photosynthesis
