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Background: While there appears to be a consensus among scientists and clinicians that body weight loss reduces the risk of several chronic diseases, these apparently favourable effects should be balanced against any potentially harmful side effect of weight loss. In this regard, weight loss has been shown to produce an increase in blood concentration of potentially toxic organochlorine pollutants in animals that can cause prejudice to health, but human data are lacking., Methods: Thirty-nine obese individuals were subjected to a hypocaloric diet during 15 weeks. Blood and subcutaneous adipose tissue samples were analysed before and after treatment for 26 organochlorine compounds. A control group consisting of 57 women of similar mean age was also formed in order to compare plasma concentrations., Results: Organochlorine pollutants were found in every subject and all 19 compounds detected had their plasma concentration increased following treatment (mean body weight loss 9.5 kg), 15 of which were statistically significant. When compared with a control group, five compounds increased significantly. These observations persisted after an 18 week low-fat diet/exercise program follow-up. Increases were correlated with body weight loss (-0.3 > or = r > or = -0.6, P<0.05) and adipose tissue analyses yielded similar results, as their concentration of organochlorine compounds increased following treatment., Conclusion: Body weight loss increases plasma and subcutaneous adipose tissue concentrations of organochlorine pesticides and PCBs in obese subjects. These results raise concerns about an undesired and potentially harmful side effect of weight loss in some obese patients who seem to be at greater risk of health problems than leaner subjects since they show higher organochlorine body burden.

The authors analyzed the relation between lactation history, organochlorine serum levels-in particular, 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE)-and the risk of breast cancer within a subsampe from a larger breast cancer case-control study conducted among women living in Mexico City, Mexico, between 1990 and 1995. From the original study, they selected a random sample of 260 subjects (1:1 case/control ratio). Analysis was restricted to 120 cases and 126 controls who had given birth to at least one child and had complete information on all key variables. Serum DDE levels were higher among cases (mean = 3.84 microg/g lipids, standard deviation = 5.98) than among controls (mean = 2.51 microg/g lipids, standard deviation = 1.97). After adjustment for age, age at menarche, duration of lactation, Quetelet index, and serum DDT levels, serum DDE levels were positively related to the risk of breast cancer (adjusted odds ratio (OR)Q1-Q2 = 1.24, 95% confidence interval (CI): 0.50, 3.06; ORQ1-Q3 = 2.31, 95% CI: 0.92, 5.86; ORQ1-Q4 = 3.81, 95% CI: 1.14, 12.80; test of trend, p = 0.02). The increased risk associated with higher serum DDE levels was more apparent among postmenopausal women (ORQ1-Q4 = 5.26, 95% CI: 0.80, 34.30; test of trend p = 0.03). A longer period of lactation was associated with a slightly decreased risk of breast cancer independently of serum DDE levels (OR = 0.91, 95% CI: 0.85, 0.99 change in risk per 10 months of lactation). Serum DDT level was not related to the risk of breast cancer. The data suggest that high levels of exposure to DDE may increase women's risk of breast cancer, particularly among postmenopausal women.

In this study, we identified the main hydroxylated polychlorinated biphenyls (OH-PCBs) and other chlorinated phenolic compounds and we determined their relative concentrations in whole blood from 13 male and 17 female Inuit from northern Quebec, Canada, and from a pooled whole blood sample from southern Quebec. We also determined concentrations of polychlorinated biphenyls (PCBs). Total OH-PCB concentrations were variable among the Inuit samples, ranging over 2 orders of magnitude (0.117-11.6 ng/g whole blood wet weight). These concentrations were equal to and up to 70 times those found for the southern Quebec pooled whole blood sample. Geometric mean concentrations of total OH-PCBs were 1.73 and 1.01 ng/g whole blood for Inuit men and women, respectively, and 0.161 ng/g whole blood for the southern population pool. There are limited data available for comparison, but the levels of OH-PCBs in Inuit are higher than those previously reported in the literature for other populations. There was a significant correlation (p < 0.005) between OH-PCBs and PCBs (r = 0.84) and both correlated significantly (p < 0.005) with age (r = 0.68 and 0.78, respectively). The ratio of OH-PCBs to PCBs was lower in Inuit (0.11) than in the southern Quebec pool (0.33). There is no apparent explanation for the difference. There was considerable variability in the congener pattern of the identified OH-PCBs. The main metabolite, 4-OH-CB109 (4-OH-2,3,3',4', 5-pentachlorobiphenyl), constituted 12-62% of the total OH-PCBs in the samples. Pentachlorophenol (PCP) was the dominant phenolic compound in blood, constituting 46% (geometric mean) of the total quantitated chlorinated phenolic compounds. PCP concentrations in Inuit blood ranged from 0.558 to 7.77 ng/g on a wet weight basis. All but two Inuit samples had lower concentrations than the southern Quebec pool (6.29 ng/g). The possible role of OH-PCBs in mediating PCB-induced adverse effects needs to be investigated further.

Food composition data were determined for food consumed by 226 Inuit women in Nunavik, estimating the relative contribution of traditional and market food for energy, protein, lipid, carbohydrate, vitamin A, vitamin D, iron, calcium, magnesium, phosphorus, selenium, zinc, and eicosapentaenoic and docosahexaenoic acids. Traditional Inuit food was an important source of protein, vitamin D, iron, selenium, and phosphorus, as well as the main source of eicosapentaenoic and docosahexaenoic acids. The mean contribution of traditional and market food to energy and nutrients was analyzed according to age groups (18-39 and 40-74). Analysis of Inuit women's nutrient intake showed that the contribution of traditional food was greater in the older group than in the younger group, for whom the contribution of market food was greater. Market food contributed the most to Inuit women's energy intake, while 40% of the intake of several nutrients, including protein, vitamin D, iron, phosphorus, and zinc, was derived from traditional food. Inuit women had low vitamin A and calcium intakes. Traditional food had low calcium and vitamin A concentrations, and the Inuit infrequently consumed market food such as milk, dairy products, and yellow and green vegetables. Thus, even though the present study showed that traditional food was the major source of many nutrients in the Inuit diet, market food was also important for the nutritional status of this population, particularly young women. In promoting safe nutritional habits among the Inuit, dietitians must help them maintain traditional food use, which has provided some health advantages (e.g., a lower incidence of cardiovascular disease); encourage consumption of nutritious market foods; and consider the societal values reflected in the traditional diet.

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.

Several organochlorines identified as "hormone mimics" were proposed as possible risk factors for breast cancer. We conducted a case-control study to assess breast cancer risk and disease aggressiveness in relation to plasma concentrations of several organochlorine compounds. Plasma lipid concentrations of 11 chlorinated pesticides and 14 polychlorinated biphenyl congeners were measured in 315 women newly diagnosed with breast cancer, 219 hospital-based controls, and 307 population controls from the Quebec City area (Canada). Concentrations of hormonally active organochlorines or their surrogates were compared between cases and controls as well as between groups of cases defined according to tumor size and axillary-lymph-node involvement. We found similar levels of organochlorines in cases and controls and no relationship between the relative risk of breast cancer and organochlorine exposure. However, the probability of lymph-node invasion among cases increased with exposure to 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene [p,p'-DDE; odds ratio, 2.54; 95% confidence interval (CI), 1.20-5.35; between the highest and the lowest tertiles]. Furthermore, p,p'-DDE exposure was associated with a dose-related increased relative risk of exhibiting both lymph-node involvement and a large tumor. Indeed odds ratio raised to 2.33 (95% CI, 0.94-5.77) for the second tertile relative to the first tertile and reached 3.51 (95% CI, 1.41-8.73) for the third tertile relative to the first tertile. Similar associations were noted with beta-hexachlorocyclohexane, oxychlordane, and transnonachlor. We conclude that exposure to persistent, hormonally active organochlorines during adulthood is not associated with breast cancer risk. The possibility that some organochlorines and especially p,p'-DDE may increase breast cancer aggressiveness deserves further attention.

Organochlorines are persistent lipophilic compounds that accumulate in Inuit people living in circumpolar countries. Organochlorines accumulate as a result of the Inuits' large consumption of sea mammal fat; however, available data are limited to blood lipids, milk fat, and adipose tissue. We report results of organochlorine determination in liver, brain, omental fat, and subcutaneous abdominal fat samples collected from deceased Greenlanders between 1992 and 1994. Eleven chlorinated pesticides and 14 polychlorinated biphenyl congeners were measured in tissue lipid extracts by high-resolution gas chromatography with electron capture detection. Mean concentrations of polychlorinated biphenyls, 2, 2'-bis(4-chlorophenyl)-1,1-dichloroethylene, ss-hexachlorocyclohexane, hexachlorobenzene, mirex, trans-nonachlor, and oxychlordane in adipose tissue samples from Greenlanders were 3-34-fold higher than those measured using the same analytical method in samples from Canadians in Quebec City, Quebec. Brain lipids contained lower concentrations of all organochlorines than lipids extracted from other tissues. Organochlorine residue levels in lipid extracts from liver, omental fat, and subcutaneous abdominal fat samples were similar, with the exception of ss-hexachlorocyclohexane, which reached a greater concentration in liver lipids than in lipids from both adipose tissues (4-fold; p < 0. 05). Comparisons with available international data on adipose tissue levels reveal that the organochlorine body burden in the Inuit population of Greenland is presently among the highest resulting from environmental exposure.

This paper assesses the impact on human health of exposure to current levels of environmental contaminants in the Canadian Arctic, and identifies the data gaps that need to be filled by future human health research and monitoring. The concept of health in indigenous groups of the Arctic includes social, cultural, and spiritual dimensions. The harvesting, sharing and consumption of traditional foods are an integral component to good health among Aboriginal people influencing both physical health and social well-being. Traditional foods are also an economic necessity in many communities. Consequently, the contamination of country food raises problems which go far beyond the usual confines of public health and cannot be resolved by health advisories or food substitutions alone. The primary exposure pathway for the contaminants considered in this paper is through the traditional northern diet. For the Inuit, the OCs of primary concern at this time from the point of view of exposure are chlordane, toxaphene, and PCBs. Exposures are higher in the eastern than in the western region of the North. For Dene/Metis, exposure to OCs is in general below a level of concern. However, estimated intake of chlordane and toxaphene has been found to be elevated for certain groups and is a cause for concern if exposures are elevated on a regular basis. The developing foetus and breast-fed infant are likely to be more sensitive to the effects of OCs and metals than individual adults and are the age groups at greatest risk in the Arctic. Extensive sampling of human tissues in the Canadian north indicate that a significant proportion of Dene, Cree and Inuit had mean maternal hair mercury levels within the 5% risk-range proposed by the WHO for neonatal neurological damage. Based on current levels, lead does not appear to pose a health threat while cadmium is likely only a major risk factor for heavy smokers or consumers of large amounts of organ meats. Consumers of traditional foods are exposed to an approximately seven-fold higher radiation dose than non-consumers of traditional foods due predominantly to the bioaccumulation of natural radionuclides in the food chain. Risk determination for contaminants in country food involves a consideration of the type and amounts of food consumed and the sociocultural, nutritional, economic, and spiritual benefits associated with country foods. Risk management options that minimize the extent to which nutritional and sociocultural aspects of Aboriginal societies are compromised must always be considered.

Organochlorine compounds bioaccumulate in fishing and hunting products included in the daily diet of many coastal populations. Prenatal and perinatal exposure to large doses of PCBs and PCDFs was shown to be deleterious on fetal and neonatal development, but information is scarce regarding possible effects of chronic low-dose exposure. This study investigates biomarkers of early effects in newborns from women exposed to organochlorines through the consumption of species from marine food chains, in two remote coastal regions of the province of Quebec (Canada). A CYP1A1-dependent enzyme activity (EROD) and DNA adducts were measured in placenta samples obtained from 30 women living on the Lower-North-Shore of the St. Lawrence River and 22 Inuit women from Nunavik (Arctic Quebec). These biomarkers were also assessed in 30 women from a Quebec urban center (Sept-Iles) as a reference group. Prenatal organochlorine exposure was determined by measuring these compounds in umbilical cord plasma. The amount of bulky polycyclic aromatic hydrocarbon (PAH)-related DNA adducts was significantly greater in the Lower-North-Shore group than in the reference group. Placental EROD activity and the amount of less bulky (OC-related) DNA adducts were significantly higher in the Nunavik group than in the reference group. For both biomarkers, smoking was found to be an important confounding factor. Organochlorine exposure was significantly associated with EROD activity and DNA adduct levels when stratifying for smoking. This study confirms that CYP1A1 enzyme induction and DNA adducts in placental tissue constitute useful biomarkers of early effects induced by environmental exposure to organochlorines., (Copyright 1999 Academic Press.)

In an exploratory study, levels of cadmium in whole-kidney and liver tissues of 314 subjects from the general population of the province of Quebec (Canada) were measured postmortem. Frequency distributions of cadmium concentrations were lognormal. As reported in similar studies, age and especially smoking habits were the main variables affecting cadmium concentrations. The geometric mean of whole kidney concentrations (wet weight) was 17.62 microg/g, with a minimum concentration of 2.25 microg/g and a maximum of 100.61 microg/g. Mean concentrations of cadmium in kidneys increased with age, reaching a plateau in the group 50 to 59 yr (29.49 microg/g), and falling slowly thereafter.

We conducted this study to evaluate blood levels of lead, mercury, and organochlorine compounds in newborns in the Province of Quebec. During 1993 to 1995, we carried out a survey in 10 hospitals located in southern Quebec. During that time, umbilical cord blood samples were obtained from 1109 newborns, and we analyzed each for lead, mercury, 14 polychlorinated biphenyl congeners, and 11 chlorinated pesticides. We used the geometric mean and 95% confidence interval (CI) to describe the results. Mean concentrations of lead and mercury in cord blood were 0.076 micromol/l (95% CI = 0.074, 0.079) and 4.82 nmol/l (95% CI = 4.56, 5.08), respectively. The mean concentrations of total polychlorinated biphenyls (Aroclor 1260) and dichlorodiphenyl dichloroethylene were 0.514 microg/I (95% CI = .493, 0.536) and 0.412 microg/l (95% CI = 0.390, 0.435), respectively. We observed a statistically significant relationship between maternal age and cord blood concentrations of (a) lead, (b) mercury, (c) polychlorinated biphenyls, and (d) dichlorodiphenyl dichloroethylene. In addition, maternal smoking during pregnancy was associated with cord blood lead levels. The cord blood concentrations of lead, mercury, polychlorinated biphenyls, and dichlorodiphenyl dichloroethylene we measured in our study were the lowest levels recently reported in industrialized countries. The results of this study underline the role of public health authorities in the evaluation of biological levels of environmental contaminants among children for the assessment of risk of adverse health effects.

This article documents the exposure to environmental contaminants within sub-groups of the Canadian population who are considered to be at risk as a result of the food they eat. We measured the concentrations of polychlorinated biphenyls (PCBs) and mercury in the blood drawn from the umbilical cords of newborns in various Aboriginal communities, in a coastal community and in the general population. Average concentrations of Aroclor 1260 ranged between 0.3 and 2.0 micrograms/L and were clearly highest among the Inuit of Nunavik and Baffin Island and among the Montagnais of Quebec. In these groups, we found contaminant levels in the blood of newborns that exceed the threshold beyond which cognitive impairments are expected to result. Average concentrations of mercury ranged between 1.0 and 14.2 micrograms/L; the Inuit of Nunavik and the NWT exhibited the highest exposure levels. A portion of the Nunavik and NWT Inuit had concentrations beyond the critical threshold for the appearance of neurological consequences. The variations in exposure levels resulted from the different nutritional practices of these Canadian sub-groups.

Objective: To compare mean concentrations of organochlorine in women with a new diagnosis of endometriosis and in controls., Design: Case-control study., Setting: Women attending an institutional clinic of reproductive endocrinology., Patient(s): Cases and controls were selected among women who underwent laparoscopy for chronic pelvic pain, infertility, or tubal fulguration between January 1994 and December 1994. Eighty-six women with endometriosis and 70 controls, matched for the indication for laparoscopy, were recruited., Main Outcome Measure(s): Mean organochlorine plasma concentrations of 14 polychlorinated biphenyl congeners and 11 chlorinated pesticides were compared between the cases and controls. Analysis of covariance was used to adjust means for confounding variables, and odds ratios were estimated by logistic regression., Result(s): Crude geometric mean concentrations did not differ significantly between cases and controls for any of the organochlorine compounds. Similarly, crude or adjusted means of the sum of polychlorinated biphenyl congeners, the sum of chlordanes, or the sum of dichlorodiphenyltrichloroethanes did not differ between the groups. There was no significant linear trend in the adjusted odds ratios for endometriosis as organochlorine concentrations increased., Conclusion(s): These results suggest that exposure to polychlorinated biphenyls and chlorinated pesticides during adulthood is not associated with endometriosis in the general population.

The purpose of this investigation was to examine whether inhaled nitric oxide (NO) may alter oxidative stress parameters and induce lung inflammation in moderate hyaline membrane disease (HMD). Eighteen moderately premature lambs (130 days gestation, term = 147 days) were randomly assigned to treatment with 20 ppm inhaled NO (n = 8) from the onset of ventilation or used as control (n = 10). Except inhaled NO, treatments were intentionally similar to those applied in clinical situations. The main studied parameters were oxidative stress index measurements on lung parenchyma and in circulating blood, lung parenchyma microscopic examination and bronchoalveolar lavage cell count. We found that 20 ppm of inhaled NO for 5 h did not change significantly either malondialdehyde and total antioxidant status levels in circulating blood, or malondialdehyde, reduced glutathione, glutathione peroxidase and glutathione reductase in lung parenchyma. Amino-imino-propene bond generation, which are lipoperoxidation markers, was similar in both groups. Furthermore, no significant changes in the number of inflammatory cells in lung lavage products and in lung parenchyma microscopic examination could be found. Therefore, these data do not support the hypothesis that short-term NO inhalation increases oxidative stress and lung inflammation in an experimental model of moderate HMD.

Purpose: This paper documents the problem of iron-deficiency anemia in the Inuit region of Nunavik, in Northern Quebec, particularly among pregnant women and infants. It also addresses the issue of Helicobacter pylori gastritis as a possible cause of anemia in this population., Method: Data on anemia in pregnancy are from routinely collected prenatal records. Data on anemia in infants are drawn from blood samples collected for a study on the impact of environmental contaminants. Helicobacter serologies were done on cord-blood specimens from 100 consecutive births screened for contaminant exposure. For comparison, serologies were done on a series of cord-blood specimens from 99 births in Southern Quebec., Results: By term, 40% of pregnant women in Nunavik are anemic (Hgb < 115 g/L). Of infants aged 9-14 months, 58% are anemic (Hgb < 110 g/L), and among the remaining 42%, over half have depleted iron stores. Twenty-seven percent of the Nunavik sample had positive or equivocal Helicobacter serologies. In the comparison group, 10% were positive or equivocal.

A microfluorometric method for the detection of low levels of cytochrome P450 was developed to increase the sensitivity of the assay, since a low level of CYP450 associated enzymatic activities was expected in human placenta tissues and small samples of placenta (approximately 10 g) could be easily collected, stored and processed. The dual fluorescence assay of Kennedy et al. [1], which was developed to simultaneously quantitate microsomal proteins and ethoxyresorufin-O-deethylase (EROD) activity was adapted for 96 wells microtiter plates. Placental microsomes samples were analyzed. For samples obtained from non-smoking mothers from the general southern Quebec population, results ranged from less than 1-3.3 pmol/mg protein.min. Samples collected from smoking mothers showed activity levels ranging from 30-69 pmol/mg protein.min. These results showed the suitability of the microassay for measuring low level of CYP450 activity in tissues such as placenta.

In this study, investigators assessed exposure to dioxin-like compounds in a fishing population that inhabits small coastal communities along the Lower North Shore of the St. Lawrence River, Quebec. This population relies heavily on wildlife foods for sustenance. Investigators analyzed chemically the most popular marine foods (i.e., fish, crustaceans, sea mammals, and sea-bird eggs), and they also obtained 25 human plasma samples from individuals in two villages along the river. The mean level of total polychlorinated biphenyls in this population was approximately twice that found in the entire fishing cohort. Plasma levels of dioxin-like compounds, expressed as tetrachlorodibenzodioxin toxic equivalents, were approximately eight times higher than levels in urban residents. Most of the increase in tetrachlorodibenzodioxin toxic equivalents in the selected fish eaters resulted primarily from an elevation in polychlorinated biphenyls. Concentrations of dioxin-like compounds from the Lower North Shore were low in fish and seals, but concentrations were elevated in the eggs of sea birds. Given that there was also a significant statistical correlation in the entire population between human plasma levels and consumption of birds' eggs-and not other traditional foods-much of the increased human dose appeared to originate from this one food source. Because there appear to be increased, but uncertain, health risks from this elevated body burden, investigators advised the residents of the area to avoid consumption of wild birds' eggs (i.e., a food source of minor nutritional importance).

High levels of cadmium in the liver and kidneys of caribous and sea mammals of the Canadian Arctic have led to recommendations to remove such offal from the traditional diet. Blood cadmium levels have been found to be very high in samples of Inuit volunteers, hence the hypothesis that the Inuit might be exposed to cadmium through their diet. This survey of a population-based random sample of Nunavik residents (n = 518) confirms that blood cadmium of Inuit is indeed very high by comparison to published reports. Blood cadmium levels are closely associated with the current smoking status and are independent of dietary patterns among nonsmokers. Plasma omega-3 fatty acids concentrations have been used to assess the reliability of the dietary information collected by questionnaires and to test for any association of blood cadmium with the consumption of sea mammals. Blood cadmium levels are not related to the reported consumption of sea mammals. Blood cadmium levels are very high among smokers and are associated with levels of exposure to tobacco. Among nonsmoking Inuit, blood cadmium levels are comparable with those reported in nonsmokers elsewhere in the world. In reference to international standards, blood cadmium concentrations are high enough among the Inuit to warrant energetic public health interventions.

Inuit people residing in the Arctic are unusually exposed to organochlorines through their traditional diet which includes large quantities of sea mammal fat. Recently, 499 Inuit adults from Nunavik (Arctic Quebec) participated in a large health survey and donated a blood sample for organochlorine and heavy metal analysis. Twenty pooled plasma samples were formed, each made of individual samples from the same age group, sex, and region of residence, to allow for dioxin-like compound determination. The mean total concentration of PCBs and dioxin-like compounds (the latter expressed in 2,3,7,8-TCDD toxic equivalents) were respectively 4.1 mg/kg lipids and 184.2 ng/kg lipids, compared to 0.13 mg/kg lipids and 26.1 ng/kg lipids for three control pooled plasma samples from Southern Quebec. Total PCBs and dioxin-like compound concentrations were strongly correlated (r = 0.98; p < 0.0001), increased with age and were greater in men than in women. Although the body burdens of PCBs and dioxin-like compounds are close to those which induced adverse health effects in laboratory animals, dietary benefits from the sea-food based diet still outweigh the hypothetical health risks.

Objectives: This study documented the concentration of polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethylene (DDE) in the breast milk of women from Quebec, Canada, and assessed the impact of various sociodemographic and lifestyle factors on these levels., Methods: From 1988 to 1990, milk samples were obtained from 536 Quebec women and analyzed for seven PCB congeners and p,p'-DDE. Information was obtained on subjects' physical, sociodemographic, and lifestyle characteristics., Results: Mean concentrations were 0.52 mg/kg lipids (95% confidence interval [CI] = 0.50, 0.54) and 0.34 mg/kg lipids (95% CI = 0.32, 0.35) for PCBs (Aroclor 1260) and DDE, respectively. Age and history of breast-feeding showed statistically significant correlations with PCB and DDE concentrations., Conclusions: Concentrations of PCBs and DDE measured in this study are at the lower end of the concentration range recently reported for women living in industrialized countries. The modulating factors identified here should be considered when conducting studies on organochlorine exposure and disease.

Inuit people living in the Arctic receive an unusually high dose of dioxin-like compounds through their traditional diet, which comprises large amounts of fatty tissues from various sea mammal species. During breast feeding, the mother transfers part of their body burden to its newborn. We estimated the impact of breast feeding on the body burden of Inuit from birth to age 75 years. Simulations performed with a toxicokinetic model revealed that breast feeding strongly influences body burden during childhood but not after age 20 years. Liver and adipose tissue concentrations expected in Inuit are well below those which induced severe adverse health effects in laboratory animals, e.g. cancer and reproduction. However, these concentrations approach levels generating subtle effects on reproductive systems.

Traditional food is culturally, economically and nutritionally important for the Greenlandic Inuit people. In the 1970s the preventive effect of marine fat on cardiovascular disease, thrombosis and atherosclerosis was described. The low incidence of ischemic heart disease among Greenlanders has been related to the high intake of marine food. Since 1990 routine autopsies have taken place in two towns in Greenland, Nuuk and Ilulissat. The autopsies represent 26% of the total number of deaths in these two towns. Samples have been collected from 104 autopsies. International cooperative studies have analysed specimens in relation to ischemic heart disease as a benefit related to diet, as well as the level of heavy metals and organochlorine in organs as a risk related to diet. High amounts of mono-unsaturated and Omega-3 poly-unsaturated fatty acid were found in adipose tissue. Liver analyses of selenium have confirmed the expected high intake among Greenlanders. Reduced atherosclerotic lesions were found in the coronary arteries. Blood pressure levels calculated from renovascholopathia of hypertension indicate prevailing levels similar to those in industrialized countries. Some factors in Greenland may be protecting the coronary arteries, thereby of setting the expected effect of hypertension. The level of methyl mercury in organs is generally high. PCB concentrations found in organs of Greenlanders are higher than among other populations. Health and risk effects of the traditional foods need further investigation.

In view of the levels of human exposure to priority contaminants assessed in previous surveys in Nunavik, a series of risk reduction scenarios were produced to modelize the effects of different potential health advisories on limiting exposure of women of reproductive age to these contaminants, as well as on maximizing nutritional benefits derived from the consumption of country food. This paper presents part of the results, in particular as regards effects of reducing PCB intake by 46%, 65% and 86%.

Persistent contaminants such as heavy metals and organochlorine compounds are transported from distant sources to the Arctic by oceanic and atmospheric currents. Natives inhabiting the Arctic can be exposed, because they exist at the highest trophic level of the arctic aquatic food chain, along which biomagnification of contaminants occurs. We reviewed the data available on heavy metal and organochlorine body burden in natives from different regions of Nunavik (northern Québec) and assessed the potential risk of health effects. In addition, we investigated the relationship between each contaminant plasma level and omega-3 fatty acid content of plasma phospholipid, a surrogate measure for aquatic food consumption. Cadmium exposure appears to be unrelated to the consumption of species from the aquatic food chain (r = 0.0004; P = 0.99), whereas PCBs and mercury were (r = 0.49 and 0.52, respectively; P < or = 0.0001). Mean blood mercury levels measured in northern Québec natives were below those associated with significant neurological disorders. Typical daily intakes of dioxin-like compounds, PCBs, DDE, and dieldrin were estimated from the mean concentration in milk fat and pharmacokinetic models. The calculated PCB intake (0.3 microgram/kg/day) exceeds the acceptable daily intake, with effects on reproduction and development being the most relevant to assess in future epidemiological studies.

Chloroform is a known contaminant of chlorinated drinking water and of swimming pool water disinfected with chlorine or one of its derivatives. Few data exist regarding the importance of dermal and inhalation exposure routes to the chloroform body burden resulting from domestic and recreational use of chlorinated water. In our experimental study involving 11 male swimmers, we quantified the body burden resulting from exposure to various concentrations of chloroform in water and air of an indoor swimming pool, during a daily 55-min exercise period. From the first to the sixth exercise period, CHCl3 mean concentration in water was increased from 159 micrograms/l to 553 micrograms/l. Corresponding mean air CHCl3 level ranged from 597 ppb to 1630 ppb. To dissociate the dermal exposure route from that of inhalation, swimmers used scuba tanks during an additional exercise period. Chloroform concentrations were measured in alveolar air before and after each exercise period, as well as after 35 min of physical activity. Chloroform levels in water and air were measured every 10 min. We examined the relationship between alveolar air concentration (a measure of body burden) at 35 and 55 min and environmental chloroform concentrations by using multiple regression models. The natural logarithm of alveolar air concentration was strongly correlated with aqueous chloroform concentration both at 35 (p2 < 0.001, r2 = 0.75) and 55 min (p < 0.001, r2 = 0.86). The relationship with air concentrations was also statistically significant (35 min: p < 0.001, r2 = 0.58, 55 min: p < 0.001, r2 = 0.63).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood cadmium levels were measured in 554 persons without any known professional exposure to this metal. They were grouped in three samples; one entirely of 142 Inuit, one of 212 caucasian city dwellers and one of 200 caucasian rural residents. While blood cadmium levels measured in non-smokers are comparable to those reported in published reports, those of current cigarette smokers were 10-20 times higher than non-smokers. These blood cadmium values stand in sharp contrast to what has been published so far and make the average smokers of Canadian-made cigarettes medically unfit for employment in jobs associated with potential cadmium exposure.

The microbiological quality of tap water and that of water from 50 water coolers located in residences and workplaces were comparatively studied. In addition, difference factors that might influence the bacteriological contamination of water dispensers were examined. Aeorbic and facultative anaerobic heterotrophic bacteria, total coliforms, and two indicators for fecal contamination (fecal coliforms and fecal streptococci) as well as three types of pathogenic bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, and Aeromonas spp.) were enumerated. It was found that 36 and 28% of the water dispenser samples from the residences and the workplaces, respectively, were contaminated by a least one coliform or indicator bacterium and/or at least one pathogenic bacterium. The respective proportions of tap water samples contaminated in a similar fashion were 18 and 22%, much less than those observed for water coolers (Chi2(1) = 3.71, P = 0.05). We were unable to discern the dominant factors responsible for the contamination of water coolers, but cleaning the water dispenser every 2 months seemed to limit the extent of contamination.

Two remote maritime populations were evaluated for their biological exposure to organochlorines in 1989-1990. Because of their high intake of seafood, these two populations have high biological levels. One hundred nine breast milk samples from Inuit women from Arctic Québec were analyzed to determine levels of polychlorodibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (PCBs) including non-ortho, mono-ortho, and di-ortho congeners. Total 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEqs) for PCBs were 3.5 times higher in Inuit milk samples than in 96 Caucasian milk samples. Among the 185 fishermen from the Lower North Shore of the Gulf of the St. Lawrence River, we evaluated 10 highly exposed fishermen for their coplanar PCB blood levels. Total TEqs were 900 ng/kg for highly exposed individuals with 36 ng/kg for controls. In these two nonoccupationally exposed populations, coplanar PCBs make a larger contribution to the TEq than PCDDs and PCDFs. However, the mono-ortho penta CB No. 118 is the major contributor for the total toxicity.

Inuit people (Eskimos) are likely exposed to persistent organochlorine compounds because their traditional diet includes fatty tissues of the arctic marine biota. Here we present the results of organochlorine compound analysis in milk fat samples from arctic Québec Inuit women and in fat tissues from various animal species inhabiting that region. The total concentration of polychlorinated biphenyl congeners in Inuit milk fat was similar to that of the beluga, while the profile of the 10 congeners resembled that of the polar bear. Mean concentrations of various organochlorines in milk-fat samples from Inuit women were between 2 and 10 times greater than those found in samples previously collected from southern Québec women. The Inuit mothers exhibit the greatest body burden known to occur from exposure to organochlorine residues present in the environment by virtue of their location at the highest trophic level of the arctic food web.

We evaluated the impact of the ring-billed gull (Larus delawarensis) on the microbiological quality of water. We measured fecal coliforms, Salmonella spp., and Aeromonas spp. in the gull droppings and the number of fecal coliforms in the water prior to and after attracting these birds to the beach with food. Gulls can contribute to the bacteriological degradation of recreational water.

Carbon monoxide (CO) released from the exhaust of ice resurfacing machinery is frequently found in indoor ice skating rinks. We conducted a study with 14 male adult non-smokers unexposed occupationally, who played hockey games in 4 different atmospheric CO concentrations. To document absorption, we measured their alveolar CO (alvCO). Exposure was the average CO level in the rink during the game. Environmental concentrations were between 0.0 (undetected) and 76.2 parts per million (ppm). The exposure-absorption relationship was linear (regression parameters: r2 = 0.93, slope = 0.411, intercept = -1.45). This means that for each 10 ppm of CO in the indoor air, the players absorbed enough CO to raise their alvCO by 4.1 ppm (approximately 0.76% carboxyhemoglobin). Taking into account the duration of the games, the regression coefficients were almost similar to those of an earlier study we made with 122 adult male hockey players playing in recreational leagues of the Quebec city area. These results show the exposure-absorption relationship for an acute 60-minute exposure, in a design which eliminated certain of the uncontrolled variables of our first study. It also emphasizes the importance of prevention for CO pollution in indoor skating rinks.

We evaluated alveolar carbon monoxide (CO) levels of 122 male, adult hockey players active in recreational leagues of the Quebec City region (Canada), before and after 10 weekly 90-minute games in 10 different rinks. We also determined exposure by quantifying the average CO level in the rink during the games. Other variables documented included age, pulmonary function, aerobic capacity, and smoking status. Environmental concentrations varied from 1.6 to 131.5 parts per million (ppm). We examined the absorption/exposure relationship using a simple linear regression model. In low CO exposure levels, physical exercise lowered the alveolar CO concentration. However, we noted that for each 10 ppm of CO in the ambient air, the players had adsorbed enough CO to raise their carboxyhemoglobin (COHb) levels by 1 percent. This relationship was true both for smokers and non-smokers. We suggest that an average environmental concentration of 20 ppm of CO for the duration of a hockey game (90 minutes) should be reference limit not to be exceeded in indoor skating rinks.

We documented the risks associated with windsurfing on sewage polluted water. Seventy-nine windsurfers and 41 controls were studied over a nine-day period for occurrence of symptoms of gastroenteritis, otitis, conjunctivitis, and skin infection. Relative risks were 2.9 for occurrence of one or more of these symptoms and 5.5 for symptoms of gastroenteritis. Relative risk increased with the reported number of falls into the water.