10 August 2009

Fireworks and balloons: harmless?

Fireworks may contain some bizarre ingredients, from aluminum to Vaseline and even the stuff of rat poison, according to a report.
Photo from the Straits Times blog.

The report also shares that in recent years, chemists have worked to develop more environmentally friendly fireworks, in part because one ingredient, perchlorate, was found in higher than normal concentrations in a lake where fireworks were shot off, and the chemical is known to cause thyroid problems in humans.

It's a good thing then, I suppose, that fireworks are let off only once a year, over the waters of the Marina which will become one of the reservoirs providing Singapore with drinking water. Well, twice if you include the rehearsal.

Helium balloons were also released at the National Day Parade. Sadly, balloon releases kill marine life, here's some examples.

Astonishingly, I learnt that DK had written to the NDP organising committee about negative impact of releasing balloons well BEFORE the event. Despite giving these reassurances to DK:
We are aware of your concerns and are working closely with National Environment Agency (NEA) on how we can balance pollution concerns viz-a-viz the artistic creativity the NDP 09 Show require for a meaningful and memorable celebration for Singapore.
They went ahead with the release! Read more about this on NDP Exco turns a deaf ear on environment hazard warning from Dee Kay Dot As Gee.

More media reports about fireworks:

From the Straits Times blog 9 Aug 09;
Melissa (Marina Bay Grandstand, 8:07pm): The grandstand is awash with a sea of red and white hearts. The Singapore Flyer too is glowing red and white. White lights, bringing out the patterns in the Flyer, blink to the music. Against the song "Home", it is a very heartwarming moment. The song ends with red heart-shaped helium balloons released into the sky, fading in the distance.
We saw showers of light
The Straits Times 10 Aug 09;
FOR the team behind the sights and sounds of the National Day Parade, hearing spectators cheer when fireworks rain gold from the night sky is a rush.
But when 27,000 people fall silent in awe, the tingles run up their spines even more. 'Twenty-seven thousand people being quiet is very powerful,' said Mr Brian Gothong Tan, the parade's visual effects director.

The crowd whooped and cheered the 21/2-minute fireworks finale, which lit up the sky at the end of the National Anthem. Patterns of hearts and starbursts in a kaleidoscope of colours filled the night sky like drops of fire.

An appreciative Shaun Wong, a 21-year-old student, said: 'The fireworks were awesome, and their synchronisation with the performance was much better than in previous years.'

Almost 800 rounds of fireworks were fired at 15 key moments in the show, the work of 30 civilian contractors working on a precise schedule, supported by 80 Singapore Armed Forces personnel.

Overseeing the fireworks display for a second time was Colonel Tham Tiem Foo, who called it a 'heavy responsibility'. 'Your hair stands when you see the fireworks, and the crowd cheers. It is an emotionally charged moment,' he said.

Retiree Kway Yew Tong, 70, who has seen four parades live, voted for this one as his favourite: 'The sense of history this year is very strong. This is very good for the younger generation.'

New fireworks for NDP
938LIVE, Today Online 6 Aug 09;
Two new fireworks effects will be seen at the National Day Parade this year. One is a red-coloured double heart, the other is a silver star, revealed the chairman of the Fireworks Committee, Lieutenant Colonel Tham Tiem Foo.

The fireworks will be fired from three barges anchored around Marina Bay. Spectators will only get to enjoy two-and-a-half minutes of the display.
The Strange Ingredients in Fireworks
livescience.com Yahoo News 2 Jul 09;
Fireworks for the 4th of July are all about light, color and sound. But inside, there are some bizarre ingredients, from aluminum to Vaseline and even the stuff of rat poison.

An ancient mix of black powder, essentially gunpowder little changed from its invention in China a millennia ago, gets each rocket in the air by creating pressure in gas trapped in a tube, or mortar.

Two fuses are lit at once: one to ignite the black powder, and another that burns slower, creating a well-timed explosion high in the sky.

The shells of commercial fireworks contain a powdery concoction of chemicals that produce the bangs and the whistles, as well as the pretty effects. Tubes, hollow spheres, and paper wrappings work as barriers to compartmentalize the effects. More complicated shells are divided into even more sections to control the timing of secondary explosions.

Big booms and whistles come from flash powder. Once used for flashes in photography, it is a combination of fuel-like metal and a chemical that feeds oxygen to fire up the fuel.

Different combinations of metals and oxides produce a whole array of sounds.

While ancient Greeks and Romans used bismuth in their beauty care products and coins, chemists add bismuth trioxide to the flash powder to get that crackling sound, dubbed "dragon eggs." Ear-splitting whistles take four ingredients, including a food preservative and Vaseline.

The variety of color in a fireworks show depends on the mix of metals.

* Copper produces blue sparks.
* A mix of strontium salts, lithium salts and other stuff makes red.
* Aluminum and titanium put the white stars in an aerial flag.
* Barium, also used in rat poison and glass making, makes green.
* Calcium burns orange and sodium, yellow.

In recent years, chemists have worked to develop more environmentally friendly fireworks, in part because one ingredient, perchlorate, was found in higher than normal concentrations in a lake where fireworks were shot off, and the chemical is known to cause thyroid problems in humans.

Meanwhile, to light up a red, white, and blue flag, chemists can lay out the emblem's design on wax paper. The pattern you see up in the air, whether it's a smiley face or a bow tie, mirrors the arrangement of the metals in the shell.

Because the flag, or any other pattern, shoots out from the shell as a two-dimensional image, people watching the show from different angles can't always tell what they're looking at. To make sure everyone has a good view, pyrotechnists tend to send duplicates into the sky at the same time.

You can see fireworks before you hear them because light travels faster than sound.

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