Health risks to infants from exposure to PCBs, PCDDs and PCDFs

Global contamination by a variety of anthropogenic persistent organic chemi cals, such as dioxins and PCBs, has resulted lit human exposure throughout all phases of development. Detectable concentrations of PCBs and dioxins ha ve been found in amniotic fluid, placenta and foetal tissue samples while i nfants who are breast-fed can obtain blood levels greater than those of the ir mother's, In two separate food poisoning episodes where infants were exp osed in utero to elevated levels of heat-degraded PCBs (PCBs, PCQs, PCDFs), a variety, of adverse mental and physical developmental abnormalities have been observed. In additional human cohorts where exposure could be conside red as environmental or background, more subtle effects, including lower bi rth weights, alterations in thyroid hormones and lymphocyte subpopulations and detriments in neurological development, have been consistently seen. bl most instances, negative associations were made between in utero exposure to contaminants compared with lactational. Although the observed neurodevel opmental deficits have been described as subtle, there could be unknown con sequences related to future intellectual functionality. Current regulatory efforts should focus on identification and control of environment and food chain contamination as in utero exposure is a direct consequence of the acc umulated maternal body burdens.