Two strikes and you're out?

The Southern Californian Childrens' Health Study (CHS) has made major contributions to our understanding of the effects of pollution on the lung health of children, and all but the most one-eyed adult physician have come to acknowledge the lifelong health effects of impaired lung growth in childhood. In this issue, the CHS suggests that both regional and near-roadway pollution affected spirometric indices in children (see page 540, hot topic). Of course these studies are complex and subject to differing interpretation, as an accompanying editorial points out (see page 503). In the ideal study, exposures would be measured on an individual rather than a community basis. However, a favourite dictum of the late, very great David Denison (Obituary, see page 591) was, ‘if you cannot measure something very accurately, measure it a large number of times’, and certainly the CHS is an impressively huge study. In the meantime, it is difficult to think of a mechanism whereby living close to a busy road is a GOOD THING. What …