| A | B |
|---|
| Acid Precipitation | Highly acidic rain, sleet, or snow that results from the release of oxides of sulfur and nitrogen into the air from burning fossil fuels. |
| Acid Shock | Sudden influx of acidic water caused by melting acidic snows that rush into lakes and streams, killing large numbers of fish and amphibians and affecting the offspring of others. |
| Air Pollution | Conditions in which the air contains substances harmful to living things. |
| Primary Pollutant | Pollutant put directly into the air by human activity, such as soot from smoke. |
| Secondary Pollutant | Pollutant that forms when a primary pollutant or a naturally occurring substance, such as water, comes into contact with other primary pollutants and a chemical reaction takes place. |
| Sick-building Syndrome | Condition of buildings with particularly poor air quality; frequently caused by sealed windows and poor air circulation. |
| Smog | Air pollution over urban areas that reduces visibility; combination of the words smoke and fog. |
| Thermal Inversion | Atmospheric condition in which the air above is warmer than the air below, sometimes trapping pollutants near the Earth's surface. |
