Fireworks get their splendor from a variety of chemicals, such as potassium chlorate, potassium perchlorate, potassium nitrate, sodium benzoate, sodium oxalate, ammonium perchlorate, strontium nitrate, strontium carbonate, sulfur, charcoal, copper oxide, polyvinyl chloride, iron, titanium, shellac, dextrine, phenolic resin, and aluminum. Many of these are toxic to birds, wildlife and humans. Fireworks often contain carcinogenic or hormone-disrupting substances that can seep into soil and water, not to mention the lung-clogging smoke they release and plastic debris they scatter.

Many of the chemicals in fireworks are also persistent in the environment, meaning they stubbornly sit there instead of breaking down. That’s how mercury from coal emissions winds up in fish, and it’s how DDT thinned bald eagles’ eggshells in the ’70s.

Perchlorate, a propellant used in fireworks, is often found in surface and groundwater and is harming aquatic creatures and contaminating drinking water. Over 286 million Americans get their drinking water from a community water system with 68% of those using surface water and 32% using groundwater. The Environmental Protection Agency determined in 2011 that the perchlorate required regulation, but later determined to not regulate the contaminant. (Read More)

In 2014, the EPA oversaw the removal of contaminates from soil and groundwater at a Superfund site where high concentrations of perchlorate were found. The site has been used to store, test and manufacture fireworks, munitions, and pyrotechnics. The area’s groundwater was so contaminated, it resulted in the closure of nearby public drinking water supply wells. 

While there isn’t much data that proves fireworks are polluting nearby bodies of water, there is little doubt that the chemicals contained in those fireworks are hazardous to health and the environment.