Across
- 3. Precipitation with low pH levels
- 6. Smog formed by sunlight acting on pollutants
- 10. Poisonous gas from incomplete combustion
- 12. Major greenhouse gas
- 14. Ground-level pollutant harmful to respiratory health
- 15. Potent greenhouse gases
- 16. Gas from burning fossil fuels
- 19. Device reducing vehicle emissions
- 20. Carcinogenic compound found in emissions
Down
- 1. Gases trapping heat in the atmosphere
- 2. Pollutant from vehicle emissions
- 4. Tiny solid or liquid particles in the air
- 5. Hazardous material used in insulation
- 7. Pollutant from agriculture and waste
- 8. Toxic metal from old paint and gasoline
- 9. Radioactive gas from natural sources
- 11. Highly toxic pollutants from waste burning
- 13. Mixture of smoke and fog
- 17. Emission from building materials and furniture
- 18. Vapor from coal burning and industrial processes