HEALTH-STATUS AT BIRTH OF INUIT NEWBORN PRENATALLY EXPOSED TO ORGANOCHLORINES

Inuit women from the Kativik region of the Province of Quebec display an unusually high body burden of organochlorine compounds. We investigated the possible effect of the in utero organochlorine exposure on the health status of Inuit newborns, as evaluated by birth weight, height, head circumference and TSH blood levels. Correlation analysis revealed statistically significant negative associations between male height at birth and the concentration of HCB, mirex, PCBs and PCDDs/PCDFs (TEQs) in milk fat. In contrast, positive associations were observed between female birth height and PCBs/PCDDs/PCDFs (TEQs) concentration. The associations between male newborn height and organochlorines remained statistically significant when controlling for mother age and the length of pregnancy. The Kativik region (Arctic Quebec) is located north of the 55-degrees parallel, in the Province of Quebec. 6500 Inuit are scattered along a 2000-km seashore line. Because fish and sea mammals are major components of their traditional diet, these population are exposed to unusually high quantities of bioaccumulating contaminants such as heavy metals and organochlorines. In 1988, we found very high levels of polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethene (DDE) in the milk of 24 Inuit women from Hudson Bay. Levels of PCBs were 5 times greater than those of 48 caucasian women living in the southern part of the province1. In view of these data, we conducted a one year follow-up study of all babies (breast-fed and bottlefed) born between July 1989 and July 1990. The follow-up period ended in July 1991. One objective of this study was to evaluate exposure of breast-fed babies to various organochlorine compounds (OCs). Because levels of contaminants in milk lipids are similar to those in blood lipids from both mother and foetus, we used breast milk levels as an indirect measure of foetal exposure. Secondly we wanted to identify the main factors associated with organochlorine exposure and finally we assessed the health risk for babies exposed prenatally and postnatally (breast-feeding) to these contaminants. We present in this paper the preliminary results of the cohort study with special focus on the health status at birth, especially variables that have been linked to in utero organochlorine exposure in previous studies: height, weight, head circumference and TSH blood levels2-4.