Hairspray.

CFC, a dangerous gas that is released into the air. It kills the ozone layer and therefore creates a chain reaction to skin diseases and such.
Sources include air-conditioners, spray-on deodorants and yes, Hairspray.
There are people out there who use up to one can of hairspray a day. Since we can't reach them, WE have to be the ones responsible. Unless you are Bill Kaulitz, please use hair gel, mouse, or styling spray.

This look isn't suitable for everyone anyways.