There is a particular group of endocrine disrupting hormones that are of particular concern. These are fat loving (lipophilic), resistant to metabolism, and are able to bioconcentrate (bioaccumulate) in the food chain. They bioaccumulate because of their fat loving characteristic – they are stored in body fats. From the fat they are transferred to the developing offspring via the placenta or via the egg. Because they are stored in the fatty tissue they can bioaccumulate up the food chain.
Mammals also can transfer these chemicals to their offspring during breast feeding when the contaminants are again mobilised and transferred to the newborn.
Breast feeding is still much more beneficial (for the baby and the environment) than bottle feeding. Breast feeding mothers need to ensure their diet contains a large percentage of organic food to limit the chemical transfer to their babies.
Marine mammals store large amounts of body fat to help maintain adequate body temperature.
Because of this and because huge quantities of pesticides and agricultural chemicals end up in the oceans, these mammals are at greatest risk.