Q: I’ve always wondered whether fireworks are polluting. Any idea?

A: Not sure why we have to send giant sparklers into the sky to mark any major event, but we do. And really, except for those who hate oohing crowds, own a dog that soils itself whenever the skies crack with thunder or had an uncle who lost an eye to a backyard light show gone awry, most people love a good dose of fireworks. The elbow-?knocking crowds that gather at Ontario Place for the Festival Of Fire this week prove that one.

Still, your suspicions are, you might say, bang on. Fireworks do come with ramifications beyond teen­agers ending up in the ER after pointing the bloody things at their friends. (Every year, a whopping 10,000 North Americans find themselves in hospitals thanks to fireworks accidents.)

Anyone with asthma knows all that smoke that follows the cavalcade of lights can be hard on the lungs. So what’s in that magic dust? It all depends on who’s making the fireworks, but they generally contain a witches’ brew of hazardous compounds. For one, they’re likely loaded with perchlorate. That’s the same stuff that’s used in rocket fuel, explosives, road flares and air bag inflation systems. It’s hazardous to human and aquatic health and messes with thyroid function. Problem is, fireworks are often fired over water (like Lake Ontario), and a 2002 study published in Environmental Science & Technology found that fireworks cause serious spikes in perchlorate contamination (up to 1,000 times background levels) for up to 80 days.

The whole perchlorate mess has put the squeeze on the military in particular to clean up its act somewhat. (Defence contractor Lockheed Martin was hit with a class action in 03 after the company leaked perchlorate into the water supply and residents argued it was giving them cancer). At the very least, the mili­tary is now working with low-?perchlorate, high-nitrogen technology for flares.

Beyond greening the army, high-?nitrogen tech is also greening the rock ’n’ roll side of pyrotechnics. Any KISS fan knows how hazy an arena can get when you set off a few dozen fireworks (entirely separate from the toke-induced haze), so most bands and smaller indoor events have switched to the high-?nitrogen type because they’re low-smoke.

Flying high on nitrogen-heavy fire­works also means you get to reduce the amount of heavy metals in­volved. (No, not the heavy metal coming from the stage area – I’m talking metals like copper that create pretty colours when they explode in the sky.) Though no one’s getting their hues from toxic mercury and lead any more, they just can’t seem to green the colour green itself, made with fairly hazardous bar­ium. At least the high-?nitrogen types need only a fraction of the metals to go rainbow-bright.

Unfortunately, these fancy new fireworks cost more, so you won’t often find them at large outdoor events like Ontario Place’s Festival Of Fire, though city of Toronto reps swear their Canada Day explosives were the low-?smoke variety.

Still, perchlorate isn’t the only pollutant involved in light shows. Another big part of the smoke is the “black powder” (aka gunpowder, a mix of saltpetre, charcoal and sulfur, if you must know) used to propel fireworks skyward since the Chinese invented them 1,000 years ago.

Pollution complaints from residents living near the nightly show at Disneyland in California pushed Disney to come out with black-powder-?free fireworks. Now Disney shoots its fairy dust to the sky with cleaner and quieter compressed air instead.

Of course, this technique is even more expensive, so you won’t find it anywhere in Toronto either.

Nevertheless, the people behind Festival Of Fire, Concept Fiatlux, say they’re taking steps to green their outdoor shows (and use high-nitrogen for their indoor ones). They stay away from plastic shells that send thousands of little fish-?choking bits into the water and onto the ground and use only 100 per cent biodegradable paper shells instead. They send collected debris and waste to Turtle Island for recycling.

They also try to buy high­er-quality fireworks from Italy and Spain instead of cheap Chinese imports (source of 98 per cent of the North America’s fireworks) – a good move considering the deadly fires at illegal fireworks sweatshops in China in recent years.

At the end of the sweaty summer day, nothing’s going to stop Cana­dians from kicking off our celebrations with a bang (and I won’t be a party pooper and tell you you can’t enjoy them), but don’t sink your bucks into putting on your own show. On top of showering your yard with toxins (including traces of persistent dioxins), the backyard variety come with an especially dangerous component: idiocy. Continent-?wide, a few thousand morons accidentally burn down their houses when fireworks go wrong. Last year, during Saint-Jean-Baptiste in Quebec, some family fireworks hit the roof of a half-?constructed house and ended up causing $1 million in damage to six houses-?in-?the-?works. That’s a lot of wasted wood and noxious insulation up in smoke for the sake of a little homegrown entertainment.