ESS Topic 8.3 Urban air pollution - SL and HL (new syllabus)

Urban air pollution (8.3.1)

Harmful substances released into the atmosphere in cities from human activities. Smog blanketing Mexico City reducing visibility to less than 5 kilometers.

Nitrogen oxides (8.3.1)

A group of gases containing nitrogen and oxygen produced mainly from combustion. Vehicle engines produce nitrogen dioxide that contributes to brown haze.

Sulfur dioxide (8.3.1)

A gas produced by burning fuels containing this element. Coal-fired power plants in India release emissions causing respiratory problems.

Carbon monoxide (8.3.1)

A colorless, odorless toxic gas produced by incomplete combustion. Car exhaust in gridlocked traffic releases this substance endangering health.

Particulate matter (8.3.1)

Tiny solid or liquid particles suspended in air. Desert dust, construction debris, and vehicle emissions create this type of contamination.

PM2.5 (8.3.1)

Fine particles with diameter of 2.5 micrometers or less. Smoke from Delhi's burning crop stubble produces dangerous concentrations.

PM10 (8.3.1)

Larger particles with diameter of 10 micrometers or less. Road dust and construction sites produce these suspended solids.

Primary pollutant (8.3.2)

A contaminant that is directly active at the point of emission. Sulfur dioxide released directly from factory smokestacks.

Secondary pollutant (8.3.2)

A contaminant formed by chemical reactions in the atmosphere. Ozone forms when sunlight reacts with nitrogen oxides and volatile compounds.

Anthropogenic (8.3.2)

Originating from human activities. Coal burning for electricity is a human-caused source of contamination.

Fossil fuel combustion (8.3.3)

The burning of coal, oil, or natural gas for energy. Beijing's coal-heated homes contribute to winter contamination.

Tropospheric ozone (8.3.3)

Ground-level ozone that acts as a contaminant. High concentrations in Los Angeles cause breathing difficulties during summer.

Photochemical smog (8.3.3)

A mixture of primary and secondary contaminants forming in sunlight. Los Angeles experiences this hazy mixture when sunlight reacts with vehicle emissions.

Volatile organic compounds (8.3.3)

Carbon-containing gases that easily evaporate and contribute to haze formation. Paint fumes and gasoline vapors release these substances into the atmosphere.

Catalytic converter (8.3.4)

A device reducing harmful emissions from vehicle exhausts. Modern cars use these devices to reduce nitrogen oxide emissions.

Acid rain (8.3.5)

Precipitation containing elevated levels of nitric and sulfuric compounds. Norwegian lakes acidified by contamination from UK factories 1,000 kilometers away.

Leaching (8.3.6)

The removal of nutrients from soil by water. Acidic precipitation causes calcium and magnesium to wash from forest soils.

Aluminum solubilization (8.3.6)

The release of toxic aluminum from soil into water when pH drops. Acidic precipitation mobilizes this metal in Swedish lakes killing fish.