Given the current consumer activist frenzy over biotech foods, it seems strange to think that yesterday’s biggest concern about food was pesticide residues. Most prominently, about ten years ago, the growth regulator, Alar, was on top of the list of environmental health hazards. Despite claims from some groups, the scientific consensus was that Alar residue on apples has never caused disease or death in humans. The main lesson about the Alar scare in my opinion is that it pays to be skeptical ab…