Types of reproductive dysfunction
Chemicals can interfere with fertility by acting at virtually any of the sites that control sexual function. In men, toxicants have been shown to have a number of effects: altering hormone concentrations and hormone metabolism (lead and dichlorodiphenyltrichloroethane (DDT)); interfering with Leydig cells (DBCP); disrupting spermatogenesis (DBCP); and reducing seminal plasma volume (ethylene dibromide, (EDB)).
In women, adverse effects have been found in hypothalamic pituitary function (lead, DDT, polychlorinated biphenyls (PCB), polybrominated biphenyls (PBB)); granulosa cells (mercury); and ovarian follicles (polycyclic aromatic hydrocarbons, cadmium).
Infertility is only one part of the spectrum of reproductive disorders caused by environmental toxicants. Other effects include early and late miscarriage, congenital abnormality, premature delivery, low birth weight and stillbirth.
Sexual dysfunction and premature menopause can also develop. Although these may all result in the inability to have normal healthy children, the scope of this chapter will be limited to those effects
resulting in inability to conceive and not the inability to carry a normal pregnancy through to a live delivery.