Studied by 1 personlithosphere
the crust of the Earth; soil, rocks, all other surface materials
hydrosphere
all of the water on the earth (liquid, frozen, and vapor)
atmosphere
air above surface of earth
biosphere
all biological matter on Earth (living and dead)
geosphere
non-biological spheres of the environment (lithosphere, hydrosphere, and atmosphere)
residence time
The average amount of time that an \n atom or a molecule remains in a \n compartment before it is removed in \n some way
% oxygen in the atmosphere
21%
% nitrogen in the atmosphere
78%
residence time of oxygen in the atmosphere
5000 years
residence time of nitrogen in the environment
10 million years
nitrogen fixation
process of converting free nitrogen in the air into chemically combined nitrogen
% CO2 in the atmosphere
0.039%
Hazardous chemical are:
Flammable
Explosive
Corrosive
Toxic
Allergenic
Toxin/poison
substance that causes injury, illness, or death of a living organism
Toxicology
study of poisons, their effects, detection, identification, and antidotes
biotoxins
toxic substances produced by organisms for defense or other reasons
“Silent Spring”
written by Rachel Carson; brought attention to widespread use of pesticides; partially led to ban of DDT in US
environmental toxicology
study of toxins in the environment
environmental health toxicology
study of the effect of toxins on human health
ecotoxicology
study of the effects of toxins on an ecosystem in the environment
threshold dose
a dose below which a toxin shows no observable effect
LD50
the dose at which 50% of the individuals die (mg toxin/kg body mass)
acute toxicity
manifests its effect in a relatively short period of time
type of toxicology results from relatively brief periods of exposure to a toxin
chronic toxicity
manifests itself over a longer period of time
type of toxicology results from long periods of exposure to a toxin
No Observed Effect Level (NOEL)
the highest dose at which no effect is observed (lies slightly above the threshold dose)
Carbon dioxide dissolves in water to form…
carbonic acid
Continuous processes operating with little change for long periods of time are called…
sustainable
Limestone is a very compressed form of…
calcium carbonate
Nitrogen fixation is the process that converts…
Atmospheric nitrogen gas to useful compounds of nitrogen
Photosynthesis is the process by which…
Water and carbon dioxide are converted to carbohydrates and oxygen
Respiration is the…
Breakdown of carbohydrates with oxygen to form water and carbon dioxide
Is nitrogen gas reactive?
no, highly unreactive
is oxygen gas reactive?
yes, highly reactive
The compartments of our planet are
Hydrosphere, lithosphere, atmosphere, and biosphere
The only significant way oxygen (O2) enters the atmosphere is through…
photosynthesis
Which of the following cycles does not have an atmospheric component?
phosphorus
Which of the following produces useful nitrogen compounds to fertilize crops?
Nitrogen fixation through lightning discharges
Nitrogen fixation with nitrogen-fixing bacteria such as Rhizobium
Fertilizers produced by the Hager Process from elemental nitrogen and hydrogen
Poisons that show up in the environment due to the activities of our society are known as
environmental toxins
Substances which in low concentrations can cause death in test animals are known as
toxins
Toxins in the environment are generally broken down by
Water, light, and microorganisms
The sulfur cycle is similar to the
phosphorus cycle
Note
Flashcard