Module 42
What is air pollution?
Air pollution is the presence of harmful substances in the atmosphere that can damage human health, ecosystems, or materials.
What is photochemical smog and when does it typically form?
Photochemical smog is a type of air pollution formed by sunlight-driven reactions between NOx and VOCs; it is most common in warm, sunny cities.
List two common indoor air pollutants.
Radon gas and formaldehyde.
What is the purpose of the Clean Air Act?
It sets national air quality standards to limit harmful pollutants and protect public health and the environment.
What causes acid rain?
Sulfur dioxide and nitrogen oxides react with water vapor in the atmosphere to form sulfuric and nitric acids.
Name two primary pollutants and explain their sources.Carbon monoxide (from vehicle exhaust) and sulfur dioxide (from burning coal in power plants).
Carbon monoxide (from vehicle exhaust) and sulfur dioxide (from burning coal in power plants).
Explain how thermal inversions worsen air pollution in urban areas.
A thermal inversion traps cooler air near the surface under a layer of warmer air, preventing pollutants from dispersing and causing smog to accumulate.
Why is indoor air pollution often more dangerous than outdoor air pollution?
Because people spend more time indoors, where pollutants can accumulate in enclosed spaces without proper ventilation.
What is a catalytic converter and how does it reduce air pollution?
It is a device in car exhaust systems that reduces NOx, CO, and hydrocarbons by converting them into less harmful gases like N₂, CO₂, and H₂O.
What are two environmental effects of acid rain?
Acidification of lakes and streams, and damage to forest ecosystems by leaching nutrients from soil.
How do primary pollutants differ from secondary pollutants?
Primary pollutants are emitted directly into the atmosphere, while secondary pollutants form when primary pollutants react in the air.
Describe the environmental and health impacts of increased atmospheric CO₂.
CO₂ contributes to global warming and climate change, which can disrupt ecosystems, melt glaciers, and increase respiratory issues due to heat stress.
What health issues are associated with exposure to asbestos?
Asbestos exposure can lead to lung cancer, mesothelioma, and asbestosis, especially in people exposed over long periods.
Name two strategies used to reduce industrial emissions.
Installing scrubbers in smokestacks and using electrostatic precipitators to remove particulate matter.
How does acid rain affect human-made structures?
It corrodes buildings, especially those made of limestone or marble, and damages infrastructure over time.
Describe how nitrogen oxides (NOx) contribute to air pollution.
NOx contributes to the formation of ground-level ozone and photochemical smog, and it can also lead to acid rain.
Compare the effects of fine versus coarse particulate matter on human health.
Fine particles (PM2.5) can penetrate deep into the lungs and even enter the bloodstream, causing heart and lung diseases, while coarse particles (PM10) typically cause respiratory irritation.
How does radon gas enter homes, and why is it dangerous?
Radon seeps in through cracks in foundations from underlying rocks; it is radioactive and increases the risk of lung cancer.
Explain how cap-and-trade systems work to reduce emissions.
Governments set a limit on total emissions and issue permits; companies can trade these, creating an economic incentive to pollute less.
What are some sources and health effects of noise pollution?
Traffic, construction, and industrial activity can cause hearing loss, stress, and sleep disruption.
Evaluate the role of human activity versus natural sources in global air pollution levels.
While natural events like wildfires or volcanic eruptions release pollutants, human activities such as fossil fuel combustion and industrial processes are the dominant sources of persistent and concentrated air pollution.
Analyze how geographic and meteorological factors influence smog formation and persistence.
Factors like topography (e.g., valleys), low wind speeds, and high temperatures can trap pollutants and intensify smog, especially in cities surrounded by mountains.
Assess how socioeconomic factors affect exposure to indoor air pollutants.
Low-income households may lack access to proper ventilation, rely on biomass for cooking, or live in older buildings with asbestos and lead paint, increasing health risks disproportionately.
Evaluate the effectiveness and challenges of international efforts to reduce air pollution.
Agreements like the Kyoto Protocol and Paris Agreement promote cooperation, but enforcement, unequal contributions, and political resistance limit success.
Propose and defend a plan to reduce the impacts of acid rain in a region heavily reliant on coal-fired power.
Implementing scrubber technology, transitioning to renewable energy, enforcing emission regulations, and public education campaigns can collectively reduce SO₂/NOx emissions and mitigate acid rain.