Pollution of the planet
Pollution on the planet
I find it interesting how easy it is to pollute and how difficult it is to clean up the planet, or even a room.
http://www.msn.com/en-ca/news/photos/world-environment-day-humanitys-impact-on-our-planet/ss-BBkISaS?ocid=TSHDHP&fullscreen=true#image=1