UNIT 3 Topics 4-6 Flashcards
(27 cards)
What are pollutants?
Any material that causes harm to a living organism.
What is pollution?
Any alteration of the environment producing a condition harmful to living organisms.
What does ppm stand for/ what is it?
ppm: Parts Per Million, it is just a way to explain how toxic something is in a cretin quantity.
what is toxicity?
it is the ability of a chemical to harm an organism.
what is acute and chronic toxicity?
acute- serious symptoms after one exposure, immediate.
chronic- symptoms occur after large build up of chemical in body and over time. hard to research because amount of chemical is hard to establish.
What does LD 50 mean?
it stands for Lethal Dose 50%. which refers to the amout of chemical that will kill 50% of the population that it is applied too.
What does the term acceptable risk mean?
it is the term we use to explain how not all humans react in the same way to toxic chemicals because of the body and how we consume them, not all lab animals react in the same manner, be careful.
What is thalidomide and what did it do/ affect?
it is a developed drug for pregnant mothers to reduce morning sickness in the 1950/60’s which taken at the small dose of 0.5 ppm can produce children with missing limbs and birth defects.
What are persistent and non-persistent pollutants?
persistent- wastes which breakdown slowly or not at all. (pesticides, petroleum products)
non-persistent- wastes which are broken down by natural means through chemical/ bacterial reactions. (fertilizers or sewage)
What are phosphates and nitrates and what are the factors which affect oxygen levels?
they are chemicals which are found in fertilizers that promote plant growth. they are also found in water at 0.1-0.3 ppm. Excess amounts of the two create algae bloom and decomposition leads to low oxygen levels which leads to death/ injury to aquatic animals. their 4 affects on oxygen are:
- the oxygen content in water
- the turbidity(undissolved solids suspended in water and block sunlight which lovers plants photosynthesize rate)
- increased temperature decreases oxygen levels because of evaporation.
- agitation of water because when water is churning oxygen is incorporated into the water.
what are biological indicators and what are the best indicators?
bio logical indicators are living organisms which produce physical changes when there is a presence of pollutants in the environment and the best indicators are macro-invertebrates. (they detect the pollutants)
what are point and non-point sources of pollution?
point- pollutants enter the environment from a specific location. (smokestack or drainage pipe)
non-point- sources which are separated by time and location from the area polluted or dispersed over a large area. (construction sites and fertilized fields.
What is air pollution?
human activities are the leading cause of airborne pollution. all the ways which these pollutants enter the air are blown to the higher latitudes of the earth(north pole) and concentrate there due to ind patterns.
what does NIMBY stand for, and what does it mean?
Not in my backyard, its an expression that summarizes the growing waste production problem and where it will be stored.
what are some examples of natural and man made pollutants?
natural: forest fires and volcanic eruptions.
man made: burring of fossil fuels and using CFC’S
What are CFC’s and what does it stand for?
IT stands for Chlorofluorocarbons and they are a human made pollutant that was used to make Styrofoam, coolants in refrigerators and used in aerosol cans. in 1985 a zone hole was found caused by them.
How is the ozone layer broken down?
from the chemical reaction between the UV light and the CFC molecules which are the reactants. those two then form the product which is chloride ions that are a catalyst to break down the ozone layer.
What do phosphates and nitrates to do affect water pollution or surface water pollution? and how can we control it?
the two chemicals create algae bloom which results in decomposition decreasing the quality of water, so in order to control this laws are in order to take the chemicals out. (water treatment system and bio remediation)
What ways can we treat sewage or polluted water?
by using two methods:
the water treatment system-
primary: physical means of sieving and settling in tanks.
secondary: biological bacterial decomposition using tanks which pump air bubbles through water.
tertiary: uses chemicals(chlorine) to remove nitrates and phosphates.
bio remediation- the process of using living organisms to fix problems or clean polluted substances. they use their plant parts and soak it up.
What is ground water and how to we control its pollution?
ground water is the water which filters down from the surface of the earth down into the soil which makes it way down into bodies of water. it is contained in aquifers which we can drink, until it is polluted, when it is polluted it is impossible to be cleaned up. so laws to help it.
What does biodegradable mean?
a substance which can be broken down by bacteria and fungi into carbon and dioxide and water in a limited amount of time.
What are hazardous wastes?
Any discarded waste known to be poisonous, toxic, corrosive, flammable or explosive. many are found in home cleaning products.
what is managements r’s?
reduce: cut down or use less of the material to make less waste
reuse: to use a material more then once like pass it down through generations
recycle: to re-make a material into a new material by meting it down.
what are the two different types of land fill construction?
sanitary: a land fill which allows all waste but toxic material and is covered each night to reduce litter blowing away. pipes to bring up leach-ate. is lined on the bottom with a clay liner and some with a plastic liner.
secure: used for hazardous or toxic wastes only. they use a clay liner, overlay with gravel, black plastic liner and have drain pipes for leach-ate but it cannot be used ever again.
