A study at Washington State University suggests a link between the insecticide DDT and obesity. Researchers exposed pregnant rats to DDT and studied how the chemical affected successive generations of their offspring. They found that the third generation of offspring — in other words, the great-grandchildren of the exposed rats — had much higher rates of obesity than their ancestors.
This field of study, called epigenetics, looks at how environmental factors can affect the way genes are expressed, and how those traits can be passed down from one generation to the next.
The WSU study comes as DDT bans are being lifted around the world so that the chemical can be used to curb malaria by killing mosquitoes that carry the disease.
Editor’s note: This post has been changed to reflect the correct rat lineage.