Across
- 3. the presence in or introduction into the environment of a substance or thing that has harmful or poisonous effects
- 7. envelope of gases surrounding the earth or another planet
- 9. - reuse (discarded objects or material) in such a way as to create a product of higher quality or value than the original.
- 10. a place to dispose of refuse and other waste material
- 13. - relating to or derived from living matter.
- 16. something that has been emitted—released or discharged
- 17. protect (something, especially an environmentally or culturally important place or thing) from harm or destruction.
- 19. able to be maintained at a certain rate or level.
Down
- 1. the branch of biology that deals with the relations of organisms to one another and to their physical surroundings
- 2. will replenish
- 4. - highly reactive gas composed of three oxygen atoms
- 5. -convert (waste) into reusable material
- 6. biological community of interacting organisms and their physical environment
- 8. - natural home or environment of an animal, plant, or other organism
- 11. maintain (something) in its original or existing state.
- 12. trash, such as paper, cans, and bottles, that is left lying in an open or public place.
- 14. closely and neatly packed together: dense
- 15. relating to or determined by the sun
- 18. the circumstances, objects, or conditions by which one is surrounded.