Across
- 3. A person or thing that is regarded as dangerous or likely to inflict pain or misery
- 6. Water falling from the sky that contains a high concentration of pollutants
- 7. Dense forest found in tropical areas of heavy rainfall
- 11. The process by which land changes into desert
- 14. A mixture of smoke, fog, and chemical fumes
- 15. To keep something from decay, dissolution or danger
- 16. Liquid discharged as waste, as from an industrial plant or sewage works
Down
- 1. Chemical that is sprayed on crops to prevent insects from destroying them
- 2. A system involving the interactions between a community of living organisms
- 4. The spontaneous emission of radiation from atomic nuclei
- 5. Rain, snow, sleet, dew, etc, formed by condensation of water vapour in the atmosphere
- 8. Able to decay naturally and harmlessly
- 9. A mixture of decaying organic matter such as leaves, wood and manure
- 10. Part of the earth's atmosphere and surface in which animals and plants can live
- 12. Something that has a benefitial effect on environment
- 13. A substance that has been linked to causing one or more types of cancer