Human Impacts on the Environment

4. a natural substance that is not replenished with the speed at which it is consumed
6. pollution that comes from multiple sources
8. wastewater and excrement from underground drainage
10. the process by which fertile land becomes dry and infertile
14. growth whose rate becomes ever more rapid in proportion to the growing total number or size
15. the action of clearing a wide area of trees
17. the production and discharge of something, especially gas or radiation
18. particulate matter that is carried by water or wind and deposited on the surface of the land or the bottom of a body of water
19. rain or any other form of precipitation that has an unusual pH below 7
20. a resource of which there is an endless supply because it can be replenished

1. any single identifiable source of pollution
2. the presence in or introduction into the environment of a substance or thing that has harmful or poisonous effects
3. the process of being worn away by wind or water or other natural agents or the gradual destruction or diminution of something
5. a colorless unstable toxic gas with a pungent odor and powerful oxidizing properties and formed from oxygen by electrical discharges or ultraviolet light
7. the condition of being populated with excessively large numbers
9. the number of live births per thousand of population per year
10. the ratio of deaths to the population of a particular area or during a particular period of time
11. the degradation of water quality by any process that changes water temperature
12. materials or substances such as minerals, forests, water, and fertile land that occur in nature and can be used for economic gain
13. a careful preservation and protection of something
16. able to be maintained at a certain rate or level