Declare Your Independence from Toxic Fireworks Pollution

http://environment.about.com/od/healthenvironment/a/toxicfireworks.htm

Summary:
Perhaps is should come as no surprise that the fireworks displays that go on around the U.S every Fourth of July are still typically propelled by the ignition of gunpowder, a technological innovation that pre dates the American Revolution itself. And the fall out from these exhibitions includes a variety of toxic pollution that rain down on neighborhoods from coast to coast, often in violation of federal Clean Air Act standards.

Brief Response:
Depending on the effect sought fireworks produce smoke and dust that contain various heavy metals, sulfur and other noxious chemicals. Barium, for instance, is used to produce brilliant green colors in fireworks displays, despite being poisonous and radioactive