09. Atmospheric Pollution and Air Quality Free Online FlashCards

What is air pollution?

Air pollution is the presence of solid particles, liquid droplets, or gases at concentrations that harm organisms, ecosystems, materials, visibility, or climate.

How do primary and secondary pollutants differ?

A primary pollutant is emitted directly from a source, whereas a secondary pollutant forms in the atmosphere through chemical reactions.

Where does most air pollution occur?

The troposphere is the lowest atmospheric layer, where humans live and where nearly all weather and most air pollution occur.

Why is PM₂.₅ a health concern?

PM₂.₅ consists of particles 2.5 micrometers or smaller. These fine particles can penetrate deeply into the lungs and may enter the bloodstream.

How does a temperature inversion increase pollution?

A temperature inversion places warmer air above cooler surface air, preventing vertical mixing and trapping pollutants near the ground.

What causes photochemical smog?

Photochemical smog forms when nitrogen oxides and VOCs react in sunlight, producing ground-level ozone and other pollutants.

How do stratospheric and tropospheric ozone differ?

Stratospheric ozone absorbs harmful ultraviolet radiation and protects life, while tropospheric ozone irritates the respiratory system and acts as an air pollutant.

Which pollutants primarily cause acid deposition?

The main precursor pollutants are sulfur dioxide (SO₂) and nitrogen oxides (NOₓ), which can form sulfuric and nitric acids in the atmosphere.

What are major ecological effects of acid deposition?

Acid deposition can lower the pH of waters, leach calcium and magnesium from soils, mobilize toxic aluminum, and reduce biodiversity in sensitive ecosystems.

Why is indoor carbon monoxide dangerous?

Carbon monoxide is a colorless, odorless gas from incomplete combustion. It binds to hemoglobin and reduces the blood’s oxygen-carrying capacity.

What is radon and why is it hazardous indoors?

Radon is a radioactive gas produced naturally from uranium in soil and rock. It can enter buildings through cracks and is a major cause of lung cancer among nonsmokers.

What is the preferred indoor-air pollution control strategy?

Source control is the most effective first step: eliminate or reduce pollution at its origin before relying on ventilation, filtration, or cleanup.