Inuit exposure to organochlorines through the aquatic food chain in arctic québec.

Self Cite

229

We investigated whether organochlorine exposure is associated with the incidence of infectious diseases in Inuit infants from Nunavik (Arctic Quebec, Canada). We compiled the number of infectious disease episodes during the first year of life for 98 breast-fed and 73 bottle-fed infants. Concentrations of organochlorines were measured in early breast milk samples and used as surrogates to prenatal exposure levels. Immune system parameters were determined in venous blood samples collected from infants at 3, 7, and 12 months of age. Otitis media was the most frequent disease, with 80. 0% of breast-fed and 81.3% of bottle-fed infants experiencing at least one episode during the first year of life. During the second follow-up period, the risk of otitis media increased with prenatal exposure to p,p'-DDE, hexachlorobenzene, and dieldrin. The relative risk (RR) for 4- to 7-month-old infants in the highest tertile of p, p'-DDE exposure as compared to infants in the lowest tertile was 1. 87 [95% confidence interval (CI), 1.07-3.26]. The RR of otitis media over the entire first year of life also increased with prenatal exposure to p,p'-DDE (RR, 1.52; CI, 1.05-2.22) and hexachlorobenzene (RR, 1.49; CI, 1.10-2.03). Furthermore, the RR of recurrent otitis media ( [Greater/equal to] 3 episodes) increased with prenatal exposure to these compounds. No clinically relevant differences were noted between breast-fed and bottle-fed infants with regard to immunologic parameters, and prenatal organochlorine exposure was not associated with immunologic parameters. We conclude that prenatal organochlorine exposure could be a risk factor for acute otitis media in Inuit infants. Images Figure 1

Section: Discussionmentioning

confidence: 99%

“…The reason for the high incidence of middle ear infections in Inuit children is unknown. Genetically determined IgG2 deficiency may be involved (27) dieldrin) were measured in milk fat extracts using high resolution gas chromatography with electron capture detection, according to the method previously described by Dewailly et al (8).…”

mentioning

confidence: 99%

Susceptibility to infections and immune status in Inuit infants exposed to organochlorines.

Dewailly

Ayotte

Bruneau

et al. 2000

Self Cite

229

“…As a result, they have unusually high body burdens of PCBs and other organochlorine compounds. In the early 1990s, PCB concentrations in breast milk samples collected from Inuit women were about 7 times higher than the PCB concentrations in Caucasian women residing in southern Quebec (Dewailly et al 1993). The high PCB body burdens previously identified in the Inuits identify them as an important at-risk population.…”

Section: The Inuit Cohortmentioning

confidence: 95%

Effects of PCB exposure on neuropsychological function in children.

Schantz

Widholm

Rice

2003

451

294

In the last decade advances in the analytic methods for quantification of polychlorinated biphenyls (PCBs) have resulted in widespread availability of congener-specific analysis procedures, and large amounts of data on PCB congener profiles in soil, air, water, sediments, foodstuffs, and human tissues have become available. These data have revealed that the PCB residues in environmental media and human tissues may not closely resemble any of the commercial PCB mixtures, depending on source of exposure, bioaccumulation through the food chain, and weathering of PCBs in the environment. At the same time, toxicological research has led to a growing awareness that different classes of PCB congeners have different profiles of toxicity. These advances in analytic techniques and toxicological knowledge are beginning to influence the risk assessment process. As the data from ongoing PCB studies assessing the mediators of neurobehavioral outcomes in children are published, the weight of evidence for PCB effects on neurodevelopment is growing. Studies in Taiwan, Michigan (USA), New York (USA), Holland, Germany, and the Faroe Islands have all reported negative associations between prenatal PCB exposure and measures of cognitive functioning in infancy or childhood. The German study also reported a negative association between postnatal PCB exposure and cognitive function in early childhood--a result that had not been found in previous studies. Only one published study in North Carolina (USA) has failed to find an association between PCB exposure and cognitive outcomes. Despite the fact that several more recent studies have used congener-specific analytic techniques, there have been only limited attempts to assess the role of specific PCB congeners or classes of congeners in mediating neurodevelopmental outcomes. From a statistical standpoint, attempts to determine the role of individual congeners in mediating outcomes are hampered by the fact that concentrations of most individual congeners are highly correlated with each other and with total PCBs. From a toxicological standpoint, these efforts are hampered by the fact that many of the PCB congeners present in human tissues have never been studied in the laboratory, and their relative potency to produce nervous system effects is unknown. More complete information on the health effects of various congeners or congener classes would allow more informed scientific and risk assessment decisions.

“…These compounds are encountered to varying extents among women in industrially developed as well as in developing nations. Some of the highest levels of contaminants are seen among women in agricultural areas of the developing world that are extensively treated with pesticides (13) and among women in remote areas, such as the Canadian Inuit, who eat a diet rich in seal, whale, and other species high on the marine food chain that accumulate heavy burdens of persistent organic pollutants (POPs) (14).…”

mentioning

confidence: 99%

Chemical contaminants in breast milk and their impacts on children's health: an overview.

Landrigan

Sonawane

Mattison

et al. 2002

171

Human milk is the best source of nutrition for infants. Breast milk contains the optimal balance of fats, carbohydrates, and proteins for developing babies, and it provides a range of benefits for growth, immunity, and development. Unfortunately, breast milk is not pristine. Contamination of human milk is widespread and is the consequence of decades of inadequately controlled pollution of the environment by toxic chemicals. The finding of toxic chemicals in breast milk raises important issues for pediatric practice, for the practice of public health, and for the environmental health research community. It also illuminates gaps in current knowledge including a) insufficient information on the nature and levels of contaminants in breast milk; b) lack of consistent protocols for collecting and analyzing breast milk samples; c) lack of toxicokinetic data; and d) lack of data on health outcomes that may be produced in infants by exposure to chemicals in breast milk. These gaps in information impede risk assessment and make difficult the formulation of evidence-based health guidance. To address these issues, there is a need for a carefully planned and conducted national breast milk monitoring effort in the United States. Additionally, to assess health outcomes of toxic exposures via breast milk, it will be necessary to examine children prospectively over many years in longitudinal epidemiologic studies that use standardized examination protocols that specifically assess breast milk exposures. Finally, current risk assessment methods need to be expanded to include consideration of the potential risks posed to infants and children by exposures to chemical residues in breast milk.