When some 18 girls in the upstate New York town of Le Roy developed unexplained tics and twitches starting in August 2011, many were quick to suspect that the cause was toxic substances in the environment. There had been a major chemical spill there in 1970. Erin Brockovich, of movie fame, started an investigation (as did EPA). But many of the potential chemical causes were ultimately discounted. Later hypotheses about the cause included sociological, psychological, and infectious factors. Today, many of the victims are doing better.

Susan Dominus reports for the New York Times Magazine March 7, 2012. [2]