The search for environmental effects on children's health

The report by Divan et al linking early exposures to cell phones with behavioral problems in young children, published in this issue of EPIDEMIOLOGY, provides an opportunity to consider pursuit of high-risk hypotheses that could open new areas of understanding in contrast with the more common assessment of lower-risk leads. Other key considerations for epidemiologists are the requirements for selecting plausible risk factors while remaining alert to serendipitous discovery, for validating proxy measures of complex disease outcomes and exposures, and for pursuing replication of unexpected results in independent settings. In the face of unexpected findings, research consortia provide opportunities for pursuing exploratory and follow-up studies of high-risk hypotheses.