We gaze in awe at these dazzling displays of color and design that ignite the sky. One moment they’re there, and the next…they’ve completely disappeared into the night.
Or have they?
Not really. But these colorful explosions disappear so quickly, it’s easy for us to overlook their environmental impact.
What exactly are the effects of these spectacular pyrotechnics on our environment?
Not surprisingly, they propel a cocktail of chemicals into the atmosphere, some of which can harm both people and the environment in high doses. The vivid colors in the displays are produced by metallic compounds such as barium or aluminium. And these metals have varying degrees of toxicity. (See sidebar.)
But the main problem with traditional fireworks is that they contain certain oxidizers called “perchlorates.” These are needed to produce the explosion. (In fact, these compounds are so highly reactive they’re used by NASA to boost space shuttles off the launch pad.)
But, alas, what goes up must come down. When perchlorates come down, they can dissolve in water, contaminating rivers, lakes and drinking water. And they’ve been linked to hyperthyroidism in humans.
Perchlorate advocates state that the substance should all be incinerated in the sky before any can fall down to contaminate the earth. But according to EPA spokesman Skip Anderson, “Studies suggest that some perchlorate in fireworks is not combusted and therefore can wind up in the environment.”
Then there’s the issue of smoke and particulate matter. Studies have indicated that air-quality monitors spike for about three hours after a fireworks display, until the particulates drift away or settle out. Which means that fireworks can lead to significant air pollution problems.
For example, fireworks during India’s annual Diwali festival (the Hindu “festival of lights”) have been known to cause air pollution much worse than even Beijing on a bad day. In 2016, a public health alarm was issued in Delhi, after a toxic haze blanketed the city for days following the Diwali fireworks. As a result, India’s Supreme Court banned the sale of fireworks during the 2017 Diwali.
So far, the challenge to scientists has been to find replacements for perchlorates and barium that are still explosive and water resistant. They’ve met with some success.
For instance, new pyrotechnic formulas have been developed that replace perchlorate with nitrogen-rich materials or nitrocellulose that burn cleaner and produce less smoke. These formulas also use fewer color-producing chemicals, dramatically reducing the amount of heavy metals used.
Some of these eco-friendly alternatives have already been used at circuses, rock concerts and other events, but few have been used at large outdoor displays. The problem is, they’re much more expensive (at least, for now). So the challenge remains to make the greener alternatives cost-competitive with conventional fireworks, while still maintaining their dazzle and glow.
In the meantime, places like Sydney, Australia, are going the extra mile. Famous for its New Year’s fireworks display (the first on the planet to be ignited at midnight), the city has developed a program that is 100 percent carbon neutral. Here’s how:
Finally, for any residual pollution resulting from the display, the city purchases carbon offsets, to ensure the event is carbon neutral.
To eliminate fireworks from our celebrations seems a bit extreme (perhaps even unpatriotic). But maybe we can at least mitigate their effects. If you’re interested in limiting the environmental impact of fireworks this year, here are a few suggestions: