Air Quality, Mercury Pollution, Smog, and Ozone Depletion

Vocabulary flashcards covering mercury pollution, smog formation, ozone depletion, policy responses, and related health/environmental effects.

Heavy metal pollution

Contamination of air, water, or soil by toxic metals such as mercury, lead, and cadmium.

Mercury (Hg)

A toxic heavy metal released naturally (volcanoes, wildfires) and humanly (fossil-fuel combustion, smelting, incineration).

Inorganic mercury

Mercury salts; less toxic and less bioaccumulative than organic forms.

Methylmercury

The most toxic organic form of mercury; bioaccumulates and is poorly excreted.

Sulfate-reducing bacteria

Microbes that convert inorganic mercury into methylmercury, enabling entry into food webs.

Bioaccumulation

Uptake of pollutants faster than an organism can eliminate them, causing buildup in tissues over time.

Biomagnification

Increase in pollutant concentration at each successive trophic level of a food chain.

Minamata Disease

Severe mercury poisoning first observed in Minamata, Japan; caused neurological damage from contaminated seafood.

Fish advisory

Public guidance limiting fish consumption due to mercury or other contaminants.

Smokestack scrubber

Pollution-control device that removes gases or particulates (e.g., SO2, mercury) from industrial exhaust.

Photochemical smog

Brown haze formed when sunlight reacts with NO, CO, and VOCs, creating ozone and NO2.

Industrial smog

Gray pollution of soot, SO2, CO, and particulates typically from coal burning and industry.

Primary pollutant

Substance emitted directly into the air (e.g., NO, CO, VOCs) before undergoing chemical change.

Secondary pollutant

Substance formed in the atmosphere via reactions of primary pollutants (e.g., ozone, NO2).

Catalytic converter

Vehicle device using platinum, palladium, rhodium to convert NO, CO, VOCs to less toxic gases.

Aerosol (stratospheric)

Tiny particles (smoke, H2SO4) in the stratosphere that reflect sunlight and cool Earth temporarily.

Tropospheric ozone

Ground-level ozone; an air pollutant harmful to health and vegetation.

Stratospheric ozone

Ozone layer 10–50 km up that absorbs harmful UV radiation, protecting life on Earth.

Chlorofluorocarbons (CFCs)

Inert, long-lived compounds once used as refrigerants and propellants; release Cl atoms that destroy ozone.

Ozone depletion

Reduction of stratospheric ozone due to catalytic destruction by chlorine and bromine radicals.

Ozone hole

Region over Antarctica where total ozone falls below 220 Dobson Units each spring.

Dobson Unit (DU)

Measurement of total atmospheric ozone; 1 DU corresponds to a 0.01 mm layer at 0 °C and 1 atm.

Montreal Protocol

1987 international treaty phasing out ozone-depleting substances like CFCs; hailed as an environmental success.

Basal cell carcinoma

Common skin cancer whose incidence rises 2–5 % for each 1 % drop in ozone.

Cataract

Clouding of the eye lens; risk increases with higher UV exposure due to ozone loss.

Phytoplankton

Microscopic marine plants sensitive to UV-B; ozone depletion reduces their productivity.

Hydrochlorofluorocarbons (HCFCs)

Transitional CFC substitutes with shorter atmospheric lifetimes and lower ozone-depleting potential.

Indoor air pollution

Contamination inside buildings from tobacco smoke, VOCs, radon, combustion by-products, and biological agents.

Volatile Organic Compounds (VOCs)

Carbon-containing gases emitted by paints, solvents, fuels, and plants; precursors to ozone and smog.

Radon

Radioactive gas from soil and rock; major indoor air hazard linked to lung cancer.

Clean Air Act

U.S. federal law (1963, 1970, 1990) setting standards and regulations to improve air quality.

National Ambient Air Quality Standards (NAAQS)

EPA limits on outdoor concentrations of six common pollutants to protect public health and welfare.

Cap-and-trade (SO₂)

Market system established in the 1990 Clean Air Act amendment to cost-effectively cut sulfur dioxide emissions.

Geneva Convention on Long-Range Transboundary Air Pollution

1983 agreement for international cooperation to reduce cross-border air pollutants such as SO₂, NOx, VOCs, and heavy metals.