Nitrogen dioxide kills cilia, the microscopic hairs that line the nostrils and windpipe, according to research presented last week. This finding supports the argument that the gas - a component of car exhaust fumes - is responsible for increasing numbers of hay fever sufferers.
Cilia play a crucial role in the nose and airways. They beat backwards and forwards, carrying mucus and foreign bodies out of the body through the nostrils or mouth.
Robert Davies and colleagues from St Bartholomew's Hospital in London cultured epithelial cells to which the cilia are attached and exposed the cells to low concentrations of nitrogen dioxide in air. After 15 minutes' exposure to 0.4 parts per million of nitrogen dioxide, many of the cilia are damaged, says Davies. At 2 ppm all the cells are killed.
If cilia and the cells in the nose are killed by nitrogen dioxide, Davies argues that allergens from ...
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