Across
- 6. a pollution created by substanses of natural origin such as volcanic ash,sea salt particles,photochemically formed ozone and products of forest fibers
- 8. a gas that contributes to the greenhouse effect by absorbing infrared radeation
- 9. the degree to which the ambient air is pollution free
- 10. a agency of the united states frederl goverment whoses mission is to protect human and enviromental health
- 11. fog or haze combinded with smoke and other atmospheric pollutants
Down
- 1. any substance in air that could harm animals,humans,vegetation,and/or materials such pollutants may be present as solid particals
- 2. a gradual increase in the overall temperture in the earth's atmosphere generally attributed to the greenhouse effect caused by the fuel that cars burn
- 3. two distinc but related phenomena observed since the late 1970s
- 4. when pollutant emittid by cars,power plants and other sources react chemically in the presence of sunlight
- 5. the trapping of the sun's warmth in a planet's lower atmosphere
- 7. a rain or other form of precipatation that is unuseally acidic