|Methoxychlor was once used to treat crops in the United States.|
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Since methoxychlor was banned eleven years ago, people might think that it's no longer a danger. According to the mouse research, however, this assumption is wrong. The researchers believe that methoxychlor affects how genes are turned on and off and that this effect is somehow passed from one generation to the next.
Genetics is the study of genes and inheritance. Genes give us many of our characteristics. However, not all of our genes are active at any one time. Epigenetics is the study of how genes are turned on and off. The ability of a chemical exposure in a female of one generation to affect epigenetics in a subsequent generation is known as transgenerational epigenetic inheritance.
The researchers discovered that a female mouse's exposure to methoxychlor "at a range typical of high environmental exposures" increased the risk of specific health problems in her children, grandchildren and great-grandchildren. In addition, they found that the epigenomes in the sperm of the male great-grandchildren of the affected female were also altered. An epigenome is a collection of chemicals that affect genes.
The University of Washington scientists suggest that the increasing incidence of obesity today could be due to our ancestors' exposure to methoxychlor. Whether or not this is the case, the mouse discovery does suggest that we need to be careful about our chemical exposure not only for the sake of our own health but also for the sake of our descendants' health.