Smithsonian.com

courtesy of flickr user Kadath

It’s sad to say, but fireworks are not environmentally friendly. They use potassium perchlorate as an oxidizer (to provide oxygen so that the fireworks can burn). The perchlorate is a pollutant that has shown up in water supplies. In addition, those pretty colors often come from heavy metals, which can be toxic. Newer “green” fireworks replace the perchlorate with cleaner-burning nitrocellulose or nitrogen-rich materials, and the nitrogen-rich versions require less of the chemicals that produce the colors, including heavy metals. The downside is that these fireworks are more expensive.

There are other concerns, too. A Seattle man sued the city last month to stop their firework display, which takes place on the site of a former coal-to-gas plant. This clip from The Colbert Report explains it in more detail. (And see if you can spot the mention of our own Craig Welch, author of Smithsonian’s geoducks and spotted owls stories, who is one of the local reporters covering the story.)