With the long Memorial Day weekend quickly approaching, I suspect many of you are looking forward to parades and celebrations in your communities capped by beautiful fireworks shows. Unfortunately, a new study has linked the use of fireworks to significantly higher levels of perchlorate, a chemical used in fireworks and rocket fuel, in nearby waters.

Scientists sampled water from Oklahoma's Wintersmith Lake days before and after fireworks events (three consecutive Independence Day celebrations from 2004-06 and a separate November 2005 event).

As you'd expect, percholate levels prior to the festivities were miniscule. A little more than a half-day after the fireworks shows, however, perchlorate levels in the lake exploded, anywhere from 24 times to as much as 1,028 times above normal. These great differences in concentrations were blamed on wind direction, quantity of the fireworks used and how efficiently percholate oxidized while the fireworks were burning.

Even worse, percholate levels peaked at the 24-hour mark after a fireworks display, and took as along as 80 days to gradually dissipate.

The lone sliver of good news to be found: After further experiments, researchers learned microbial fauna in the lake water helped to degrade percholate, but it's dependent on the naturally occuring concentration of nitrate (fauna typically eat nitrate before eliminating percholate) in water. On the other hand, sterilized lake water, devoid of nitrate, couldn't get rid of percholate, perhaps explaining why traces have been found in breast milk and cow's milk.