6. Epidemiology

6.1 Exposure windows and potential effects on offspring

The period of exposure is crucial. Developing organisms are more vulnerable (prenatal, perinatal, puberty, etc.). Hormonal activity is permanent during foetal and juvenile life, to ensure the organism's development. In adults, hormones act intermittently according to need, making them less vulnerable to PEs.

The "window of exposure" corresponds to a stage in the development of primordial germ cells during which DNA methylation undergoes profound changes, being demethylated and then remethylated in a sex-specific manner.

Age of exposure plays a decisive role: teenage girls exposed to DDT before the age of 14 are five times more likely to develop breast cancer than those exposed...