Americans and Canadians could be celebrating the Fourth of July and Canada Day in a fog of dioxins after their usual fireworks displays this weekend. Researchers at the Technical University of Braunschweig in Germany have found high levels of the toxic chemicals in fireworks. In the latest issue of Chemosphere (), they say that blue fireworks release the most dioxins. This is because the copper responsible for their colour catalyses the formation of the poisons when chlorinated chemicals in the fireworks burn.
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