Culprit for Epidemics of Autism, Obesity: Fungicide? New study suggests chemicals' effects linger for generations By Evann Gastaldo, Newser Staff Posted May 22, 2012 12:14 PM CDT 28 comments Comments Picture taken on April 22, 2008 of a crop duster plane spraying fungicide in Tagum in Davao del Norte province, located in the southern Philippine island of Mindanao. (Getty Images) (Newser) – Can the recent increase in autism, obesity, and anxiety disorders be traced back to chemical exposure? That's what a new study involving pregnant rats suggests, AFP reports. Pregnant rats who were exposed to the common fungicide vinclozolin had descendants who, three generations later, weighed more, were less sociable, and displayed more anxiety and stress than descendants of rats who had not been exposed. That's significant because, the lead author explains, "We are now in the third human generation since the start of the chemical revolution, since humans have been exposed to these kinds of toxins." "The ancestral exposure of your great-grandmother alters your brain development to then respond to stress differently," the co-author adds. "We did not know a stress response could be programmed by your ancestors' environmental exposures." Only male descendants were tested; the studies involving females are still ongoing. The co-author acknowledges that the amount of chemical exposure was "higher than what you would expect in the environment, but there is not a whole lot known about environmental levels of this particular compound."