Lecture VIIILecture IX

AP Environmental ScienceBy Dr. Woodward

The AP Environmental Science Exam covers a one-semester introductory college course in environmental science with laboratory.

The questions included in Section I are designed to cover the breadth of students' knowledge and understanding of environmental science.

There are four questions in Section II. One is a data-set question, which requires students to analyze and interpret a given set of data. One is a document-based question in which students answer questions related to a given document (such as a pamphlet, advertisement, or newspaper article) and apply their knowledge of environmental science to contexts that are current, relevant, and authentic.

Two are synthesis questions, which are in-depth, often multi-part essays.

AP Environmental Exam

T h e Exam The AP Environmental Science Exam is 3 hours long and is divided equally in time between a multiple-choice section and a free-response section. The multiple-choice section, which constitutes 60 percent of the final grade, consists of 100 multiple-

choice questions that are designed to cover the breadth of the students’ knowledge and understanding of environmental science. Thought-provoking problems and questions based on fundamental ideas from environmental science are included along with questions based on the recall of basic facts and major concepts. The number of multiple-choice questions taken from each major topic area is reflected in the percentage of the course as designated in the topic outline (see pages 6–9). The free-response section emphasizes the application of principles in greater depth. In this section, students must organize answers to broad questions, thereby demonstrating reasoning and analytical skills, as well as the ability to synthesize material from several sources into cogent and coherent essays. Four free-response questions are included in this section, which constitutes 40

percent of the final grade: 1 data-set question, 1 document- based question, and 2 synthesis and evaluation

AP Environmental Exam

Today’s Agenda:Journal Question: What is a heavy metal?*Lecture VIII “Hazardous Chemicals & Heavy

Metals”Exam I this Friday

Lecture VIII:

1. A chemical that presents a certain hazard or risk is known as a hazardous material (HAZMAT)

2. The EPA categorizes substances on the basis of the following criteria:(1) Ignitability(2) Corrosivity(3) Reactivity (4) Toxicity

The Nature of Chemical Hazards

A. Substances that catch fire readily.(1) Gasoline, Alcohol

Ignitability

A. Substances that corrode storage tanks and equipment.(1) Acids

Corrosivity

A. Substances that are chemically unstable and that may explode or create toxic fumes when mixed with water. (1) Explosives, elemental phosphate, and concentrated sulfuric acid

Reactivity

A. Substances that are injurious to health when they are ingested or inhaled.(1) Chlorine, Ammonia, Pesticides, Formaldehyde

Toxicity

A. Containers in which HAZMAT’s are stored and vehicles that carry HAZMAT’s are required to display place cards that identify hazards.

HAZMAT Notification

A. All toxic chemicals, by definition, are hazards that pose risk to humans.

The Threat of Toxic Chemicals

A. These chemicals do not readily degrade in the environment.(1) Heavy Metals & Their Compounds(2) Synthetic Organics

Two Major Classes of Chemicals

A. The most dangerous heavy metals are lead, mercury, arsenic, cadmium, tin, chromium, zinc, and copper.

Heavy Metals

B. These metals are used widely in industry, particularly in metal working or metal-plating shops and in such products as batteries and electronics. (1) Can also be paint pigments, glazes, inks and dyes.

Heavy Metals

C. Case Study: Mercury in Fish (1) Federal Study Shows Mercury in

Fish Widespread (2010)a. Mercury contaminated fish in

300 streams tested across the country.b. Only 1/4 of these fish had levels

of mercury that exceed the EPA’s safe level

Heavy Metals

D. Heavy metals are extremely toxic because, as ions or in certain compounds, they are soluble in water and may be readily absorbed into the body.(1) They can combine and inhibit the functioning of particular vital enzymes.

Heavy Metals

E. Even very small amounts can have severe physiological or neurological consequences.(1) Lead poisoning can cause mental retardation and insanity.(2) Mercury poisoning can cause crippling birth defects.

Heavy Metals

Heavy Metal poisoning

Lead Poisoning

A. Petroleum-derived and synthetic organic compounds are the chemical basis for all:(1) Plastics(2) Synthetic Fibers(3) Synthetic Rubber(4) Solvents*(5) Pesticides(6) Hundreds of other products!!!

Synthetic Organics

B. Because of their chemical structure, many synthetic organics are resistant to biodegradation.

Synthetic Organics

C. They are toxic because they are often readily absorbed into the body, where the interfere with particular enzymes.(1) When they accumulate in the body, the effect may be acute poisoning and death.

Synthetic Organics

DDT is the first and most widely used of the synthetic organic pesticides

Pesticides: DDT

Acid Rain Effects:

Journal Question: Give an example of the two major classes of harmful chemicals.

*1. Lecture IX: Acids & Freshwater Lakes-AP Exam Essay Component-

2. Study for Exam I

Lecture IX: Acid in Freshwater Lakes

Echo Park, Los Angeles 9/28/2011

In 1868, the lake was formed to provide a source of drinking water or drinking water storage.

Echo Park

Echo Park Eutrophication 2011

It was found that in 2006 the lake that once provided drinking water now contains… Copper, Ammonia, Algae, Lead, PCB’s and low levels of oxygen (DO) that we briefly discussed during our last lecture on pollutants.

-The sludge at the bottom of the lake will be hauled off to landfills.

-The draining of this lake began this September, which is now!

Echo Park Lake (9/28/2011)

Revised Echo Park Lake 2011

Echo Park, Los Angeles (2011)

1. As pH levels decline, the biodiversity decreases.

2. As acidity decreases, the biodiversity increases.

3. As pH values increase, the biodiversity increases.

-Fresh water fish cannot live in an acidic environment-

Problems with Lake Acidification

1. Toxic (heavy, harmful) metals (such as Al, Pb, Cd, Cu, Fe, methyl mercury) are released into solution lower the pH levels.

Mercury inhibits the production of myelina. Myelin surrounds nerves.b. Symptoms effect the nervous system.

Chemical, Physiological, and Ecological Factors Effected by Lake Acidification

2. Increased nitrogen levels stimulate plant growth resulting in an algal blooms.

Chemical, Physiological, and Ecological Factors Effected by Lake Acidification

3. There is increased death and decomposition resulting in lower dissolved oxygen (DO) levels.

Chemical, Physiological, and Ecological Factors Effected by Lake Acidification

4. Reduced photosynthesis (due to plant death) leads to reduced levels of dissolved oxygen (DO).

Chemical, Physiological, and Ecological Factors Effected by Lake Acidification

5. *Acids interfere with enzyme activity.6. Acids also cause tissue damage.7. Eggs unlikely to survive in an acidic

environment.8. Acids cause bone decalcification and

interferes with calcium uptake.9. Disrupts muscle contraction (Calcium is

an important component in muscle contraction)

Chemical, Physiological, and Ecological Factors Effected by Lake Acidification

Recall: A lake is a fresh water ecosystem.1. Sulfur dioxide (S02)in the atmosphere

reacts with atmospheric gases (oxygen and water vapor) to produce sulfuric acid (acid deposition) –Acid Rain

Causes of Lake Acidification

Recall: A pH below 7 is acidic, above 7 is basic.

2. Organic acids and metallic cations in leachate flow into a lake from leaking sanitary landfills.

Causes of Lake Acidification

Leachate is the mixture of water and materials (i.e. chemicals) that are leaching.

Leaching is the process in which the materials in or on the soil gradually dissolve and are carried by water seeping through the soil.

Leachate

Leaching may eventually remove valuable nutrients from the soil, or it may carry buried wastes into groundwater, thereby contaminating it.

Leaching

3. Hydrochloric or sulfuric acid industrial wastes are discharged into a watershed (point source pollution)

Causes of Lake Acidification

4. NO2 in the atmosphere reacts with atmospheric gases (oxygen and water vapor) to produce nitric acid (acid deposition) –Acid Rain-

Causes of Lake Acidification

Sources of Acid Rain: Elevated levels of Hydrogen Ions

Potential ways to avoid or remediated lake acidification. As it relates to -Sulfur Dioxide-

1. Reduce fossil fuel use.2. Install air pollution device.3. *Develop and use alternative (non-

fossil fuel) energy sources.

Prevent Lake Acidification

As it relates to leaching:1. Monitor, collect and chemically treat

leachate. 2. *Construct and operate sanitary

landfills following strict guidelines.

Prevent Lake Acidification

As it relates to industrial wastes and a point source pollutant.

1. Solution: Stop the dumping of acidic industrial wastes into lakes.

Prevent Lake Acidification

As it relates to Nitrogen Oxides(1) Reduce the use of nitrogen fertilizer

because it is a source of Nitrogen Oxides that are vaporized into the atmosphere or released through biological activity.

(2) *Develop and use alternative (non-fossil fuel) energy sources.

(3) Burn coal more cleanly and efficiently.

Prevent Lake Acidification

Adding lime into the lake will act as a neutralizing agent.

Preventing Lake Acidification

Applicable to all solutions: Pass laws regarding lower emission

levels and enforce fines for non-compliance.

Prevent Lake Acidification

Dissolved oxygen: Oxygen gas molecules O2 dissolved in water. (1) Fish and other aquatic organisms depend on dissolved oxygen for respiration. (2) The concentration of dissolved oxygen (DO) is a measure of water quality.

Dissolved Oxygen (DO)

a. Coalb. Sunc. Aluminumd. Treese. Clay___ A potentially renewable resource.___ A nonrenewable resource and a fossil fuel.___ A nonrenewable resource and a metallic mineral.___ A nonrenewable resource and a nonmetallic

mineral.___ A renewable resource, human action has little to

do with the life-span of this resource.

What do you think?

A potentially renewable resource. (D) TreesA nonrenewable resource and a fossil fuel.

(A) CoalA nonrenewable resource and a metallic

mineral. (C) Aluminum A nonrenewable resource and a nonmetallic

mineral. (E) Clay A renewable resource, human action has

little to do with the life-span of this resource.

(B) Sun

What do you think?

2010 AP® ENVIRONMENTAL SCIENCE FREE-RESPONSE QUESTIONSVisit the College Board on the Web: www.collegeboard.com.ENVIRONMENTAL SCIENCESECTION IITime—90 minutes4 QuestionsDirections: Answer all four questions, which are weighted equally; the suggested time is about 22 minutes foranswering each question. Write all your answers on the pages following the questions in the pink booklet. Where calculations are required, clearly show how you arrived at your answer. Where explanation or discussion is required, support your answers with relevant information and/or specific examples.1. Read the following article from the Fremont Gazette and answer the questions that follow.(a) Choose any ONE of the three pollutants mentioned above and respond to each of the following.(i) Describe one specific source, other than the local chemical plants, for the toxic pollutant you chose.(ii) Describe how the pollutant you chose enters the human body and one specific effect it can have on human health.(iii) Describe TWO specific steps, other than an outright ban, that a city or nation can take to reduce the threat posed by this pollutant.

(b) Give one reason why Dr. Egguen is correct in asserting that children are particularly susceptible to toxicpollutants.(c) An important contributor to global climate change is the release of CO2 from the rapidly increasing numberof coal-burning power plants in China. Assume that the coal burned at these plants to provide the power to manufacture a single MP3 player releases 40 kg of CO2 and that it costs $0.75 to capture 1 kg of CO2 andkeep it from entering the atmosphere. Determine the cost, in dollars, to capture the total amount of CO2 released from manufacturing one MP3 player.(d) Coal-burning power plants also release other pollutants, including nitrogen oxides (NOx ), sulfur oxides(SOx ), and particulates. Select one of these pollutants and identify one technology that can be used to remove it from the waste stream of coal-burning power plants.(e) Discuss TWO reasons why a multinational company would choose to build a manufacturing facility in Indiaand/or China rather than in the United States or Europe.