Peter Bjerregaard

Organochlorines and heavy metals in pregnant women from the Disko Bay area in Greenland

Recent studies from Greenland and the Canadian Arctic have shown high concentrations of heavy metals, such as mercury, and organochlorines in the blood and fatty tissue of the Inuit. This is attributed in particular to their high consumption of the meat and blubber of marine mammals. In the present study, 180 pregnant women and 178 newborn babies were studied, amounting to 36% of the total number of births in the Disko Bay area during 1994-1996. The pesticides found in the highest concentrations in maternal blood were DDE (4.8 micrograms/l wet wt.), trans-nonachlor (1.6 micrograms/l) and hexachlorobenzene (1.2 micrograms/l) while the total concentration of PCB (Aroclor 1260) was 19.1 micrograms/l. Calculated on a lipid basis, concentrations were slightly higher in maternal than in cord blood. The mercury concentrations were 16.8 micrograms/l in maternal blood and 35.6 micrograms/l in cord blood. In a linear regression analysis, the concentrations of organochlorines, mercury and selenium increased with maternal age. Concentrations of mercury and cadmium increased with the consumption of marine mammals, and cadmium was associated with smoking. The contaminants are potentially toxic for several organ systems but the high concentrations of pollutants have so far not been shown to influence health in Greenland.

The associations of a marine diet with plasma lipids, blood glucose, blood pressure and obesity among the inuit in Greenland.

Objective: To analyse the associations between the intake of fish and marine mammals and risk factors for cardiovascular disease, ie lipid profile, fasting blood glucose, blood pressure and obesity, in a population whose average consumption of n-3 fatty acids is high compared with Western countries.Design: Information was obtained from a population survey in Greenland: interview data, clinical data and fasting blood samples were obtained from a random sample of Inuit from three towns and four villages.Subjects: Two-hundred and fifty-nine adult Inuit (74% of the sample).Results: Marine diet was positively associated with serum high-density lipoprotein (HDL) and blood glucose and inversely with very-low-density lipoprotein (VLDL) and triglyceride. Association with low-density lipoprotein (LDL), diastolic and systolic blood pressure, waist–hip ratio and body mass index were inconsistent and not statistically significant. The pattern was similar within groups with low, medium and high consumption of marine food.Conclusions: There are statistically significant associations between the consumption of marine food and certain lipid fractions in the blood also in this population with a very high average intake of marine food. The observation that blood glucose is positively associated with marine diet in a population survey is new and should be repeated. There was good agreement between the results for the reported consumption of seal and those for the biomarkers.Sponsorship: The study was financially supported by the Greenland Home Rule, Directorate of Health and Research, the Commission for Scientific Research in Greenland, and the Danish Medical Research Council.European Journal of Clinical Nutrition (2000) 54, 732–737

Lead sources in human diet in Greenland

Although blood lead levels have declined in Greenland, they are still elevated despite the fact that lead levels in the Greenland environment are very low. Fragments of lead shot in game birds have been suggested as an important source of dietary exposure, and meals of sea birds, particularly eider, contain high concentrations of lead. In a cross-sectional population survey in Greenland in 1993–1994, blood lead adjusted for age and sex was found to be associated with the reported consumption of sea birds. Participants reporting less than weekly intake of sea birds had blood lead concentrations of approximately 75 μg/L, whereas those who reported eating sea birds several times a week had concentrations of approximately 110 μg/L, and those who reported daily intake had concentrations of 170 μg/L (p = 0.01). Blood lead was not associated with dietary exposure to other local or imported food items.

Haemoglobin concentrations appear to be lower in indigenous Greenlanders than in Danes: assessment of haemoglobin in 234 Greenlanders and in 2804 Danes.

Abstract: Objective: To compare haemoglobin concentrations in Greenlanders and Danes.

Population surveys in Greenland 1993-2009: Temporal trend of PCBs and pesticides in the general Inuit population by age and urbanisation

The purpose of the study was to analyse temporal trends (1993-2009) of the concentrations of organochlorine contaminants (14 congeners of polychlorinated biphenyls (PCB) and 11 pesticides) in the blood of Greenland Inuit according to age and urbanisation. Statistical determinants for the contaminant concentrations included (for PCB congener 153) age (Δr(2)=0.35), marine diet (Δr(2)=0.10), smoking (Δr(2)=0.02), and sex (Δr(2)=0.01) with comparable results for other organochlorine contaminants. After adjustment for age, diet, smoking, and sex a significant decreasing trend was present for all contaminants ranging from 41% for mirex to 56% for hexachlorobenzene. The temporal trend was most pronounced among participants below the age of 65 years. The decrease started later in villages than in towns. The decrease was present in all age groups and in the capital, other towns, and villages. The decrease is probably due to a combination of reduced concentrations of the contaminants in the wildlife and a slight temporal reduction in the consumption of marine mammals. The significant downwards trend of legacy POPs shows that the legislation works but it must be kept in mind that according to the cumulated scientific evidence there are a multitude of non-regulated persistent organic contaminants in the diet as well as high levels of methylmercury.

Iron status markers in 224 indigenous Greenlanders: influence of age, residence and traditional foods

Abstract: Objective: To evaluate iron status in indigenous Greenlanders and its relationship to gender, age and intake of traditional Greenlandic foods. Methods: Serum ferritin, serum transferrin saturation and haemoglobin were evaluated in a population survey in 1993–1994 comprising 224 Greenlandic individuals (109 men) aged 19–82u2003yr. The participants were residents in the capital Nuuk (n=73) with a predominantly Western style of living, the town Ilulissat (n=60) with a mixture of Western and Greenlandic style of living, and the small town Uummannaq (n=91) with a predominantly Greenlandic style of living. Consumption of traditional foods was assessed by questionnaire. Results: Intake of traditional foods was more prevalent among elderly than among young individuals and more frequent in Uummannaq than in Ilulissat and Nuuk. Ferritin levels were higher in men than in women (p<0.0001). Median ferritin levels were lowest in Nuuk (men, 92u2003µg/L; women, 40u2003µg/L), higher in Ilulissat (men, 104u2003µg/L; women, 69u2003µg/L) and in Uummannaq (men, 118u2003µg/L; women, 46u2003µg/L) (p<0.001). The prevalence of iron load (ferritin >200u2003µg/L) was lowest in Nuuk (men: 13.8%, women: 2.3%) intermediate in Ilulissat (men, 11.1%; women, 9.1%) and highest in Uummannaq (men, 32.1%; women, 21.1%). The prevalence of iron depletion (ferritin <16u2003µg/L) was high in Nuuk (men, 0%; women, 20.5%), and lower in Ilulissat (men, 3.7%; women, 6.1%) and in Uummannaq (men, 0%; women, 10.5%). The prevalence of iron deficiency anaemia (ferritin <13u2003µg/L and Hb <5th percentile for iron‐replete men and women) was 0.92% in men and 0.87% in women. Correlations between age and ferritin were lowest in Nuuk (men, rs=0.26, p=0.2; women, rs=0.50, p=0.001) intermediary in Ilulissat (men, rs=0.37, p=0.06; women, rs=0.73, p<0.0001) and highest in Uummannaq (men, rs=0.59, p<0.0001; women, rs=0.74, p<0.0001). Intake of traditional foods was correlated with ferritin in men (rs=0.29, p=0.01) and women (rs=0.40, p<0.0001). Conclusion: The observed differences in estimated body iron stores in Greenlanders from the three residential areas can be explained by differences in the dietary intake of haem iron.

Health and environment in Greenland and other circumpolar areas

Before World War II, the mortality pattern in the Arctic was characterized by very high mortality due to infectious diseases, in particular tuberculosis, and to injuries. Life expectancy was low and chronic diseases such as cancer and heart disease were rare. Improved living conditions and health services have drastically altered health conditions since then. The circumpolar population groups are small and scattered, and the burden of pathogenic factors is high. The impact of environmental contaminants is therefore difficult to study epidemiologically. In the absence of local industrial sources of pollution, mercury and organochlorines in the traditional diet are presently the most serious environmental threats to human health in Greenland. Although we observe no effects on human health at present, the situation is potentially serious and should be closely monitored.

INDIGENOUS GREENLANDERS HAVE A HIGHER SERO-PREVALENCE OF IgG ANTIBODIES TO HELICOBACTER PYLORI THAN DANES

Objective: To assess the sero-prevalence of IgG antibodies to Helicobacter pylori (H. pylori) in Greenlanders and compare with the sero-prevalence in Caucasian Danes. Methods: 71 randomly recruited indigenous Greenlanders (29 men) with a median age of 39 years (range 22–76), living in the capital, Nuuk, and the town of Ilulissat, and participating in a population survey carried out in 1993–1994. The results were compared with those obtained in a 1983–1984 population survey in Copenhagen County, comprising 2794 Caucasian Danes (1425 men) with a median age of 41 years (range 30-60). Serum IgG antibody levels to H. pylori were determined by an indirect enzyme-linked immunosorbent assay in 1995 and categorised as negative, borderline (equivocal), or positive. Results: Greenlanders: 48.3 % of men and 45.2% of women had positive serum IgG antibody levels to H. pylori. In the entire series, 46.5% had positive IgG antibody levels, 25.4% displayed borderline antibody levels and 28.2% had negative antibody levels. There were no age, or gender differences concerning the prevalences of the three H. pylori IgG antibody subgroups. Danes: 25.6 % of men, and of women, had positive IgG antibody levels against H. pylori. In the entire series, 25.6% had positive IgG antibody levels, 19.0% displayed borderline antibody levels and 55.4% had negative antibody levels. There was no gender difference concerning the sero-prevalence of IgG antibodies, but the sero prevalence increased significantly with age. The prevalence of positive serum IgG antibodies against H. pylori was markedly higher in Greenlanders than in Danes (p <0.0001). Conclusion: Indigenous Greenlanders have a significantly higher infection rate with H. pylori than Danes. The results suggest that Greenlanders become infected with H. pylori early in life.