EDCs can exercise their effect on us in several ways:
- Bind to the body’s hormone receptors and mimic the hormone
- Block the action of the body’s hormone
- Stimulate the enzymes responsible for the synthesis or clearance of a hormone
- Inhibit the enzymes responsible for the synthesis or clearance of a hormone.
The effects of EDCs depend on the chemical, the stage of development of the person, and which part of the endocrine system the chemical targets. For example, if an organism is exposed to a EDC that disrupts sex hormones, when they are in the womb, then the kind of effects may include structural deformities of the reproductive tract, effects on sexual behaviour, and low sperm counts. If the primary action is on the thyroid hormones, then exposure in the womb may cause effects on intelligence and growth, since these hormones are responsible for metabolism and normal brain development. If the EDCs target the endocrine system at a higher level, eg by interfering with the brain’s release of hormones to regulate the production of other hormones, then the EDC will trigger multiple effects.