#AP Environmental Science: Smog - Your Ultimate Study Guide

Hey there, future AP Environmental Science rockstar! Let's break down smog into bite-sized pieces so you're totally prepped for the exam. Think of this as your late-night study buddy, here to make sure everything clicks. Let's dive in!

#What is Smog? 🌫️

Smog is basically a mashup of smoke and fog. It's a type of air pollution that looks like a haze or fog. There are two main types:

• Industrial Smog (aka gray/sulfurous smog)
• Photochemical Smog (aka brown smog)

#Industrial Smog (Gray/Sulfurous Smog)

• What is it? Smog from industrial emissions, especially from burning coal.
• Main Pollutant: Sulfur dioxide ($SO_2$).
• Appearance: Thick, yellowish haze.
• Where? Areas with heavy industrial activity (power plants, factories).

#Photochemical Smog (Brown Smog)

• What is it? Smog formed when sunlight reacts with pollutants.
• Main Pollutants: Nitrogen oxides ($NO_x$) and Volatile Organic Compounds (VOCs).
• Appearance: Brownish-gray haze.
• Where? Urban areas with lots of traffic and industrial activity.

#Key Vocabulary 📚

• Gray Smog: Industrial smog, mainly from sulfur dioxide.
• Sulfurous Smog: Another name for gray smog.
• Brown Smog: Photochemical smog, with nitrogen compounds giving it a brownish color.
• Photochemical Smog: Smog formed by sunlight reacting with pollutants.
• VOCs: Volatile Organic Compounds, released from vehicles, industrial processes, and even trees.
• Tropospheric Ozone ($O_3$): Ozone in the lower atmosphere; a key component of photochemical smog.

#How Does Smog Form? 🏭☀️

#Photochemical Smog Formation (Brown Smog)

1. Nitrogen Dioxide ($NO_2$) from various sources

   • Sunlight breaks $NO_2$ into NO + O
   • O + $O_2$ (with sunlight) → $O_3$ (tropospheric ozone)

   

2. Nighttime Reaction:

   • $O_3$ + NO → $NO_2$ + $O_2$

   

3. VOCs Enter the Scene:

   • VOCs react with NO, forming photochemical oxidants.
   • These oxidants disrupt the breakdown of $O_3$.
   • $O_3$ + Photochemical Oxidants = Photochemical Smog

#Industrial Smog Formation (Gray Smog)

• Pollutants like $SO_2$, particulate matter, and $NO_x$ are released from burning fossil fuels and industrial processes.
• These pollutants react to form sulfuric acid, particulate matter, and nitrogen dioxide.
• This mix creates the thick, yellowish haze of industrial smog.

#Health Concerns ⚠️

#Photochemical Smog

• Respiratory Issues: Ozone and particulate matter irritate the respiratory system, causing coughing, wheezing, and shortness of breath. Can worsen asthma.
• Cardiovascular Issues: Increased risk of heart attacks and strokes.
• Plant Damage: Reduces crop yields and quality.

#Industrial Smog

• Similar respiratory and cardiovascular problems as photochemical smog.
• Can cause acid rain due to sulfur dioxide emissions.

#Protective Measures

• People in heavily affected areas often wear surgical masks to reduce health impacts.

#Final Exam Focus 🎯

#High-Priority Topics

• Formation of Photochemical Smog: Understand the reactions involving $NO_x$, VOCs, and sunlight.
• Health Impacts: Be ready to discuss respiratory and cardiovascular effects.
• Sources of Pollutants: Know the anthropogenic and natural sources of VOCs and $NO_x$.
• Differences Between Smog Types: Clearly distinguish between industrial and photochemical smog.

#Common Question Types

• Multiple Choice: Identifying pollutants, understanding smog formation, and health impacts.
• FRQs: Analyzing real-world scenarios, proposing solutions, and connecting smog to other environmental issues.

#Last-Minute Tips

• Time Management: Quickly identify the main points of each question, and don't get bogged down in details.
• Common Pitfalls: Be careful not to mix up different types of pollution or their effects.
• Strategies: Use diagrams and flowcharts to map out the formation of smog. Use mnemonics to recall key concepts.

Air pollution, including smog, is a significant part of the AP Environmental Science curriculum. Expect it to appear in multiple sections of the exam.

#

Practice Question

#Multiple Choice Questions

1. Which of the following is a primary component of photochemical smog? (a) Sulfur dioxide (b) Carbon monoxide (c) Tropospheric ozone (d) Methane

2. Which of the following is a major source of VOCs? (a) Coal-fired power plants (b) Nuclear power plants (c) Vehicle emissions (d) Landfills

3. Industrial smog is primarily associated with which of the following? (a) High concentrations of ozone (b) Emissions of sulfur dioxide (c) High levels of VOCs (d) High levels of carbon dioxide

#Free Response Question

Scenario: A large city experiences a significant increase in photochemical smog during the summer months. The city council is seeking recommendations to mitigate this issue.

(a) Describe the chemical reactions involved in the formation of photochemical smog. (3 points) (b) Identify TWO anthropogenic sources of pollutants that contribute to photochemical smog. (2 points) (c) Explain TWO specific health effects associated with exposure to photochemical smog. (2 points) (d) Propose TWO realistic strategies that the city council could implement to reduce photochemical smog levels. (2 points) (e) For each proposed strategy, describe ONE potential challenge in implementing it. (2 points)

Scoring Breakdown:

(a) 1 point for each of the following (max 3 points): - Nitrogen dioxide ($NO_2$) breaks down into nitrogen oxide (NO) and oxygen (O) in the presence of sunlight. - The free oxygen (O) combines with atmospheric oxygen ($O_2$) to form ozone ($O_3$). - VOCs react with NO to form photochemical oxidants, which disrupt the breakdown of ozone.

(b) 1 point for each correct source (max 2 points): - Vehicle emissions - Industrial processes

(c) 1 point for each correct health effect (max 2 points): - Respiratory problems (e.g., coughing, wheezing, shortness of breath) - Cardiovascular issues (e.g., increased risk of heart attacks and strokes)

(d) 1 point for each reasonable strategy (max 2 points): - Promote the use of public transportation or electric vehicles. - Implement stricter emissions standards for industries.

(e) 1 point for each challenge (max 2 points): - Public resistance to changing transportation habits. - Economic costs for industries to adopt new technologies.

You got this! Remember to stay calm, use your knowledge, and trust your preparation. You're going to do great!