| A | B |
|---|
| acids | H ion >OH ion concentration |
| acid deposition | precipitation and dry particle fallout that is more acidic than usual |
| acid precipitation | any precipitation that is 5.5 or less |
| acute | life-threatening reactions within a period of hours or days. |
| air pollutants | substances in the atmosphere that have harmful effects. |
| ambient standards | air pollutant levels that need to be achieved to protect environemntal and human health. |
| area sources | diffuse pollution sources |
| artifacts | human-made objects |
| bases | H ion < OH ion concentration |
| buffer | substance that has a large capacity to absorb H ions and hold pH relatively constant |
| carcinogenic | cancer-causing |
| catalytic converter | a device that removes toxic substances from internal combustion engines |
| chronic | gradual deterioration of a variety of physiological functions over a period of years. |
| industrial smog | an irritating grayish mixture of soot, sulfurous compounds and water vapor. |
| photochemical smog | air pollutant resulting from sunlight interacting with primary sources. |
| pH | concentration of H ions in solution. |
| point sources | direct pollution sources |
| primary standard | the highest level of pollutant that can be tolerated by humans without noticeable ill effects |
| primary pollutants | direct products of combustion and evaporation. |
| secondary pollutants | products from reactions between pollutants and atmospheric conditions. |
| temperature inversion | effect of certain weather conditions on smog levels |
| threshold level | pollutant level below which no ill effects are observed |
