By Catherine Zandonella, M.P.H.
My mother-in-law notes that my two precious darling children are, at times, a bit unruly. I fully accept that the cause of their boisterousness is my parenting style. Nevertheless, I am intrigued by a recent scientific study suggesting that chemicals in our environment can influence the brain development and behavior of future generations.
The study found that pregnant rats exposed to a fungicide called vinclozolin could pass down changes in certain brain genes to their third generation of offspring-their grandchildren. Some of the altered genes are suspected of contributing to conditions such as schizophrenia, depression, post-traumatic stress disorder, anxiety and Alzheimer’s.
The researchers, led by Michael Skinner, a molecular and cell biologist at Washington State University, published their findings November 18, 2008 in the journal PLoS ONE. They found that those third-generation rats had altered behaviors, and that the changes in behavior and gene activity differed between males and females. Males became more hyperactive, while females became more anxious.
The chemical vinclozolin is a fungicide used on fruits and vegetables, and is a known endocrine disruptor. You may run into it as an ingredient in Scotts Vorlan EG, which is used to treat flowers and fruit trees. Skinner and his team suspect that the hormone-like action of vinclozolin disrupts the turning on and off of genes in both the reproductive cells of the embryonic rats being exposed and their pregnant mothers. These gene changes are called epigenetic because they involve the molecules that govern the turning on and off of gene activity rather than alterations of the DNA itself.
These changes in gene expression can then be passed on to offspring. Previously Skinner’s team found that vinclozolin enhanced susceptibility to disease among members of the third generation, but this was the first study to look at brain gene activity and behavior.
Skinner cautions that the study as it was designed cannot prove that the gene changes directly caused the rats anxiety-like behaviors. The rats’ parents were exposed to vinclozolin while in the womb, and may have treated their offspring differently, giving them less affection, for example, than unexposed rats give their young.
Nevertheless, the fact that exposure to synthetic chemical compounds can cause changes in behavior that we might pass on to our children and even grandchildren suggests that we should avoid purchasing or using harmful chemicals in cleaning products, lawn and garden applications, and other products at home and in the workplace. For my part, I hope my children are rowdy because they’re young, and not because of any chemicals that their grandmother may have encountered.