Posted by: Bystander PJ31 OCT 2012
At this time of year, as we celebrate Hallowe’en, Bonfire Night and Diwali, we also pollute the atmosphere with firework displays. These can produce alarming levels of air pollution that break safety limits and lead to health problems such as asthma.
Pyrotechnic products contain a wide range of chemicals. They include propellants, oxidisers, colour-producing compounds and chlorine donors (used to strengthen flame colours).
The propellant fuel is usually black powder, containing sulphur, charcoal and potassium nitrate. Oxidisers include nitrates, chlorates and perchlorates.
Zinc is used for smoke effects and other metals provide the colours: strontium or lithium for red; calcium for orange; sodium for yellow; barium for green; copper for blue; caesium for indigo;potassium or rubidium for violet; and aluminium, beryllium, magnesium or titanium for white.
When fireworks burn or explode they shoot out noxious gases, such as oxides of nitrogen and sulphur, and tiny particles of solids, all in levels greater than those produced by traffic exhausts. From the largest cake fireworks down to the tiniest indoor sparklers, they all cause similar air pollution. And the bonfires on which we burn effigies of Guy Fawkes only add to the problem.
Researchers at King’s College London and the University of Birmingham have shown that firework events can lead to concentrations of particulate matter that exceed air pollution safety limits set by the EU. Their study, reported in Environmental Science & Technology in 2010, also identified worrying health risks. Because the particles are microscopic, they are inhaled deep into the lungs, where they can trigger respiratory and cardiovascular health problems.