Across
- 3. keeping track of something for a specific purpose
- 5. layer of ozone in the atmosphere 15 to 50 km above earths surface; protects the earth's surface from the sun's ultraviolet radiation
- 6. gases in earth's atmosphere that trap the heat that forms when radiant energy from the sun reaches earth's surface
- 8. greenhouse effect made greater by humman activities, such as burning fossil fuels and clearing land, that add greenhouse gases to the atmosphere
- 11. colourless and odourless gas; produced by incomplete combustion of chemicals containing carbon
- 12. amount of a substance that causes 50% of a group of test animals to die if they are given a specified dose of the substance all at once
- 16. how poisonous a substance is
- 17. consentration of acid that can dramatically lower the ph of the water in a pound, slough, lake, or river for a short period of time
- 19. Fog or haze intensified by smoke or other atmospheric pollutants
Down
- 1. forms when sulfur combines with oxygen in the air; major air pollutant that forms both smog and acid rain; major source: industrial processes
- 2. at groung level it's a pollutant produced as a result of industrial processes and the use of motor vehicles; high in the atmosphere, it forms a layer protecting earth from the sun's ultraviolet radiation
- 4. species used to monitor the health of an environment or ecosystem
- 7. metals that have density of 5 or higher (e.g.,copper, zinc, lead, mercury, cadminum, nickel) heavy metals are one type of substance monitored to determine water quality
- 9. major air pollutant; forms when nitrogen combines with oxygen as a result of fuel combustion; gives smog its characteristic brown colour; malor source: motor vehicles
- 10. increased average temperatures worldwide caused by the enhanced greenhouse effect
- 13. poisonous
- 14. chemical used to kill pests
- 15. animals without backbones
- 18. measurement used to describe very small concentration of chemicals