ISP217 Exam 3

Question 1

pH

Answer 1

High = less acidity
Low = more acidity(as acid increases, [H+] of water increases and decreases the pH)
Caused by H+

Question 2

Unpolluted Rain Water

Answer 2

Is CO2 + H2O, so made slightly acidic by carbon dioxide (carbonic acid).

Question 3

Bog

Answer 3

Naturally acidic, low ANC (acid neutralizing capacity), sandy soils, surface mat of Sphagnum moss
–Like a cola in that it is high in H+ ions (very very acidic, low pH)

Question 4

Natural Sources of Acidity

Answer 4

• Dissolved CO2 (Carbonic acid)
• Organic acids (decay of refractory detritus) [leaves etc in water]
• Gases from natural combustion (forest fires, volcanoes)

Question 5

Anthropogenic Sources of Acidity

Answer 5

-Gases from combustion of fossil fuels:
—Sulfur dioxide (SO2) in the fuel as an impurity (natural gas, oil, coal) –power utilities
—Nitrogen oxides (NOx) comes from the air as N2, higher temp = more NOx – transportation
Acid Mine drainage - pyrite

Question 6

Spatial Distribution of Acid Deposition

Answer 6

Tall smokestacks led to air pollutants being transported long distances.
(remember wind blowing and the Coriolis effect)
Ohio Valley went straight to the Adirondacks

Question 7

Acidic Water Flow

Answer 7

Minerals dissolve
Weathering (leaching) - leads to releasing limestone bicarbonate into water, increasing ANC
Most sensitive areas of the world are also those that receive the most acid deposition

Question 8

Limestone in watershed

Answer 8

Well-buffered freshwater system, and hard water

Question 9

pH and Aquatic Species Diversity

Answer 9

Below 5 on pH scale is too low for fish

Question 10

Reversing Acidification

Answer 10

Clean Air Act great success in reducing SO2
But did not affect NOx because of increase in vehicles/milage/and lack of reduction of how much Nox per vehicle-mile large trucks may produce.

Question 11

Arguments against regulating SO2 and NOx emissions

Answer 11

1. Acidification is a natural process
2. Acidification is not reversible
3. It’s too expensive

Question 12

Toxin

Answer 12

A chemical that has direct negative effects on the survival or health of an individual organism
or
poisonous chemical.

Question 13

Types of Toxins

Answer 13

1. toxic elements (heavy metals) - “all natural”
2. man-made organic compounds
3. natural organic compounds (phytoplankton toxins)

Question 14

LD50

Answer 14

Is a measure of acute toxicity.

Question 15

Dose

Answer 15

Amount ingested

Usually expressed per unit body weight of the organism.

Question 16

TC50

Answer 16

Concentration at which 50% show some toxic effect.

Question 17

LC50

Answer 17

Concentration at which 50% of the population die.

Question 18

Botulism Toxin

Answer 18

Comes from mice and is most toxic substance on Earth.

Lethal dose is 0.0001mg.

Question 19

Chronic Toxicity

Answer 19

Fish consumption
Acute toxicity may not be a reliable indicator of chronic toxicity
Chronic toxicity is more difficult and expensive to measure than acute toxicity.

Question 20

Persistence

Answer 20

Toxic elements (heavy metals) have infinite persistence.
Man-made organic compounds.
Depends on:
Reactivity (more inert = more persistent)
Solubility (less soluble in water = more persistent)

Question 21

Bioaccumulation

Answer 21

Concentration of toxin is high in the organisms that in water.

Question 22

Bioconcentration

Answer 22

Simple chemical partitioning between the aquatic medium (water) and the body fluids of the organism.
Primary mechanism of bioaccumulation in most aquatic organisms.

Question 23

Bioconcentration Factor (BF)

Answer 23

Concentration in fish / Concentration in water
Negatively related to water solubility
Less soluble in water = higher BF and more soluble in lipids.

Question 24

Biomagnification

Answer 24

Concentration of toxin within organisms increases up the food chain.
High factors result from:
high persistence (low reactivity, low water solubility)
high uptake rate (rapidly assimilated)
low excretion rate (slowly metabolized)

Question 25

Toxic elements (heavy metals)

Answer 25

More soluble at low pH Bind to sediments Element cycles (inorganic - organic forms) Humans re-distribute (do not produce, just redistribute) Type 1: potentially toxic at any dose (lead, mercury, cadmium, arsenic) Type 2: essential nutrients at low doses, toxic at high doses (copper, zinc, chromium, selenium)

Question 26

Lead (Pb)

Answer 26

The most important heavy-metal pollutant. Binds to sediments in aquatic systems Human intake (atmosphere, food, drinking water) Inorganic lead: stored in bones Organic lead: stored in fatty tissue (bioconcentration) Causes: irreversible brain damage, learning disorders in children, anemia, poison waterfowl, scavengers

Question 27

Mercury (Hg)

Answer 27

Only metal liquid at room temperature. Vaporize and inhale Element cycles (inorganic - organic) Methyl (organic) Hg - most dangerous form Causes: irreversible brain damage, birth defects.

Question 28

DDT, DDD

Answer 28

``` Chlorinated aromatic hydrocarbons insecticides insecticidal properties discovered by Muller Killing the eagles banned in 1972 ```

Question 29

PCBs

Answer 29

Chlorinated aromatic hydrocarbons non-reactive (stable, inert) fluids Resist breakdowns electrical transformers (insulator, coolant) Causes: tumor growth, birth defects (humans) Banned in 1977

Question 30

Ocean Gyre

Answer 30

Flow of currents around the periphery of an ocean cause by atmospheric circulation (drives ocean surface currents) and wind (pulling water due to friction).

Question 31

Watts/Meter2

Answer 31

Unit, energy that hits a given area per unit time.

Question 32

Uneven Heat Distribution

Answer 32

Most sun radiation absorbed by tropical ocean, atmosphere absorbs very little. More energy absorption near the equator. leads to: warmer waters near the equator and uneven heat distribution that drives the winds.

Question 33

Monsoon

Answer 33

Pattern of win circulation that changes with seasons. Bring rains that dramatically flood areas. Affects whole countries Caused by uneven heat distribution In summer: land is hotter than ocean, air rises over land (low pressure) wind flows from ocean to land brings moisture and rain. In winter: land is cooler than ocean, air rises over ocean (low pressure), wind flows from land to ocean.

Question 34

Sea Breeze, Lake Breeze = "Mini-Monsoon"

Answer 34

Same process as monsoon, but can occur near large or small bodies of water (small lakes, great lake shoreline, ocean shoreline). - smaller scale Day: sun heats land faster than water, air rises on land and is lower pressure than over water, wind moves from over water to land. Night: opposite.

Question 35

El Niño (La Niña)

Answer 35

An oscillation of the ocean-atmosphere system in the tropical Pacific having important consequences for weather around the globe. (la niña is opposite). Occurs every 2-7 yrs. (can be strong or weak).

Question 36

Walker circulation

Answer 36

Wind circulation pattern between South America and Asia that pushes warm surface waters to west (.5 meter higher in west), cool lower water rises up to replace it in east (upwelling). Warmer water in wet causes heavy rain, east cooler and dry

Question 37

Lake Effect Snow

Answer 37

1. Cold air mass from polar regions of Canada 2. Blows over Great Lakes 3. Warmer lake water heats air, moister air rises 4. This air mass blows over land 5. Friction slows the air over land as it snows. Need: large fetch and large difference in air and water temperature for a lot of snow.