Smoke is a strange mixture of exotic pollutants and incomplete combustion products. Of course, some people smoke cigarettes for the pleasure of it. For most people smoke is unpleasant and should be avoided. Many people watch firework displays and go “wow” and the smoke from them adds a bit of the zest to the event. The metallic particles in the smoke emitted by fireworks pose a health risk, particularly to people who suffer from asthma. This is the conclusion of a study led by researchers from the Institute of Environmental Assessment and Water Research, published this week in the Journal of Hazardous Materials.