Peak flow measurements among visitors to a public health exhibition.

The results of measurements of peak flow made on 2,891 office workers and others attending a public health exhibition in the City of London have been analysed. After standardizing for height, peak flow was found to increase with age into the third decade before declining again, and there was evidence of a more rapid decline among continuing smokers than among those who had never smoked or had given up. Possible effects of exposure to air pollution were considered in terms of residential histories: mean peak flows for subjects born in London were