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The aim of this study was to replace 75% of total fish oil (FO) and alter digestible protein/digestible energy (DP/DE) in rainbow trout feeds to minimize potentially hazardous environmental contaminant exposure. Two diets differing in DP/DE ratios (18 and 25) were combined with soybean (SO), canola (CO), and a blend of canola oil and Schizochytrium sp. (COS). Dietary lipids and DP/DE ratios did not affect apparent digestibility, growth, and somatic parameters. The n-3/n-6 levels decreased significantly in the growth trial, especially for the SO groups. A short washout trial restored n-3/n-6 levels for the CO and COS groups, irrespective of the DP/DE ratio, but not for the SO groups. At all sampling events, contaminant concentrations in fish flesh were lower than limits set by regulatory agencies in Canada, the US, and Europe. Contaminants were lower in the oil replacement diets compared to FO for toxaphenes, organochlorine pesticides, and PCBs but not flame retardants during the growth phase. At the end of the washout phase, no differences were detected. Thus, this study revealed that replacing 75% of total fish oil in rainbow trout feed by CO and COS, combined with a 25 DP/DE ratio, with a washout period seems to be the most efficient approach in terms of maximizing the total FO replacement and contribute to reducing POPs exposure. [ABSTRACT FROM AUTHOR]

Dichlorodiphenyltrichloroethane ( p,p′-DDT), an organochlorine pesticide known to have deleterious health effects in humans, has been linked to hepatocellular carcinoma (HCC) in rodents. A recent study has reported that p,p′-DDT and its most persistent metabolite, dichlorodiphenyldichloroethylene ( p,p′-DDE), may also be associated with HCC in humans. To examine whether there is an association between p,p′-DDT and/or p,p′-DDE in a population at high-risk of developing HCC, a nested case-control study was conducted within the 83,794 person Haimen City Cohort in China. Sera and questionnaire data were collected from all participants between 1992 and 1993. This study included 473 persons who developed HCC and 492 who did not, frequency matched on sex, age and area of residence. p,p′-DDT and p,p′-DDE levels were determined by mass spectrometry. Hepatitis B viral infection status (based on hepatitis B virus surface antigen; HBsAg) was also determined. p,p′-DDT and/or p,p′-DDE serum levels were significantly associated with sex, area of residence, occupation, alcohol consumption and cigarette smoking. Adjusting for age, sex, area of residence, HBsAg, family history of HCC, history of acute hepatitis, smoking, alcohol, occupation (farmer vs. other) and levels of p,p′-DDT or p,p′-DDE, odds ratios (OR) and 95% confidence intervals (CI) were calculated via unconditional logistic regression. Overall, the highest quintile of p,p′-DDT was associated with an increased risk of HCC, OR = 2.96 95% CI; 1.19-7.40. There were no statistically significant associations with p,p′-DDE. Overall, these results suggest that recent exposure to p,p′-DDT may increase risk of HCC. [ABSTRACT FROM AUTHOR]

This project was initiated by the North America Commission for Environmental Cooperation (CEC). Its main purpose was to obtain an initial profile on pregnant woman's exposure to persistent organic pollutants (POPs) in North America (Canada, the United States and Mexico). Persistent organic pollutants are transferred to the fetus via the placenta during the pregnancy or to the infant via maternal milk; therefore, the pregnant woman's body burden is important because of the higher exposures and potential health effects in the fetus and infant. This paper presents the results from 240 pregnant women in 10 Mexican cities, and includes the concentrations of various POPs such as polychlorinated biphenyls (PCBs), organochlorine pesticides and polychlorinated dibenzo dioxins and furans (PCDDs and PCDFs) in maternal plasma. We found concentrations of p,p′-DDE in maternal samples from Coatzacoalcos to be ∼60% higher than those found in Ciudad Obregon, which had the second highest concentration. Pregnant women from Merida had higher mean concentrations of PCBs than all women in other regions. Results for PCDDs and PCDFs plus dioxin-like PCBs data were only available on the basis of composite samples, and their concentrations are similar in most cities except for Coatzacoalcos, which had more than double the concentration found in other cities. Although this study provides useful information on the variability of POPs in specific populations and possible regional/local differences, these results cannot be generalized to the entire Mexican population because of differences in age, gender, sources of exposure and nonrandom nature of the sample. [ABSTRACT FROM AUTHOR]

The article discusses a research study which examined the association between polychlorinated biphenyls (PCBs) levels in the plasma and the risk of cutaneous malignant melanoma (CMM). The study found that CMM risk is strongly associated with the levels of non-dioxin-line PCBs and several PCB congeners, metabolites or organochlorine pesticides in the plasma. The study suggested that other environmental factors, aside from ultraviolet radiation (UV), could play a role in the development of CMM.

Plasma organochlorines have been implicated to increase the risk of non-Hodgkin lymphoma (NHL), and interaction with the aryl hydrocarbon receptor gene (AHR) may modify this risk. In this case–control study conducted in British Columbia, Canada, five single nucleotide polymorphisms (SNPs) of AHR were genotyped in 422 NHL cases and 459 controls to measure the association between individual SNPs, haplotypes, and risk of NHL. Pre-chemotherapy organochlorine levels were measured and gene–environment interaction analysis was performed. The IVS1 + 4640G/A SNP was significantly associated with NHL risk, with an odds ratio of 1.32 (95% CI = 1.05–1.65) for G/A or A/A genotypes compared to the G/G genotype. Interactions were observed with PCB 118, a known inducer of AHR, and chlordane-related analytes oxychlordane and trans-nonachlor, although no interactions were statistically significant after controlling for multiple comparisons. The observed interactions were consistent across NHL subtypes. Results suggest that the AHR gene may play a role in determining the risk of NHL with exposure to organochlorines, and highlight the importance of understanding gene-environment interactions. [ABSTRACT FROM AUTHOR]

Background Exposure to endocrine-disrupting chemicals, such as persistent organochlorine pesticides, has been suggested to increase the risk of testicular germ cell tumors (TGCTs). Methods To study the relationship of POP exposure to TGCT risk, prediagnostic serum samples from 754 case subjects and 928 control subjects enrolled in the Servicemen's Testicular Tumor Environmental and Endocrine Determinants Study were analyzed for cis-nonachlor, trans-nonachlor, oxychlordane, total chlordanes, β-hexachlorocyclohexane, mirex, p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE), and p,p′-dichlorodiphenyltrichloroethane. Adjusted odds ratios (ORs) and their associated 95% confidence intervals (CIs) for the risk of TGCT overall and for the histological subgroups, seminoma and nonseminoma, were estimated using multivariable logistic regression. All statistical tests were two-sided. Results TGCT risk was statistically significantly associated with higher plasma levels of p,p′-DDE (for highest quartile [Q4] vs lowest quartile [Q1], OR = 1.71, 95% Cl = 1.23 to 2.38, Ptrend = .0002) and of two chlordane components, cis-nonachlor (Q4 vs Q1, OR = 1.56, 95% Cl = 1.11 to 2.18, Ptrend = .009) and trans-nonachlor (Q4 vs Q1, OR = 1.46, 95% Cl = 1.07 to 2.00, Ptrend = .026). Seminoma risk was statistically significantly associated with p,p′-DDE (Q4 vs Q1, OR = 1.91, 95% Cl = 1.22 to 2.99, Ptrend = .0008), cis-nonachlor (Q4 vs Q1, OR = 1.93, 95% Cl = 1.27 to 2.93, Ptrend = .0045), trans-nonachlor (Q4 vs Q1, OR = 1.72, 95% Cl = 1.11 to 2.67, Ptrend = .033), and a chlordane metabolite, oxychlordane (Q4 vs Q1, OR = 1.64, 95% Cl = 1.04 to 2.60, Ptrend = .048), whereas nonseminoma risk showed a statistically significant association with p,p′-DDE only (Q4 vs Q1, OR = 1.63, 95% Cl = 1.10 to 2.42, Ptrend = .0044). Conclusions Increased exposure to p,p′-DDE may be associated with the risk of both seminomatous and nonseminomatous TGCTs, whereas exposure to chlordane compounds and metabolites may be associated with the risk of seminoma. Because evidence suggests that TGCT is initiated in very early life, it is possible that exposure to these persistent organic pesticides during fetal life or via breast feeding may increase the risk of TGCT in young men. [ABSTRACT FROM AUTHOR]

BACKGROUND: Higher levels of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), the major degradation product of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT), have been related to shorter duration of breast-feeding in previous studies. If DDE truly shortens lactation, this has public health importance regarding infant mortality and the use of DDT for malaria control. OBJECTIVE: Our aim was to assess the relationship of maternal DDE concentrations with length of subsequent lactation. METHODS: We conducted a relatively large study in a highly exposed area of Mexico. We followed 784 mother-son pairs to determine length of lactation. DDE and DDT were measured in maternal serum obtained within a day of delivery. We fit proportional hazard models with and without stratifying by previous breast-feeding, because an association of DDE with duration of lactation among those who breast-fed previously could be attributed to a noncausal mechanism. RESULTS: Compared with those with DDE concentrations ≤ 3.00 μg/g, the adjusted hazard ratios of weaning according to DDE category were, for concentrations 3.01-6.00 μg/g, 1.27 [95% confidence interval (CI), 1.04-1.55]; for concentrations 6.01-9.00 μg/g, 1.23 (95% CI, 0.92-1.63); and for concentrations > 9.00 μg/g, 1.17 (95% CI, 0.92-1.49). The corresponding ratios for women who previously breast-fed were 1.40 (95% CI, 1.06-1.87); 1.91 (95% CI, 1.24-2.93); and 1.76 (95% CI, 1.22-2.53). Those for women who had not breast-fed previously were 1.14 (95% CI, 0.86-1.52); 0.90 (95% CI, 0.61-1.31); and 0.91 (95% CI, 0.66-1.26). CONCLUSIONS: Data from our relatively large study in a highly exposed area of Mexico did not support the hypothesis that exposure to DDE shortens length of lactation. The association seen in women who previously breast-fed was likely attributed to a noncausal mechanism. Nonetheless, whether DDT has other important adverse effects on humans is still an open question. [ABSTRACT FROM AUTHOR]

OBJECTIVE: We set out to assess whether environmental prenatal exposure to polychlorinated biphenyls (PCBs) is associated with incidence of acute respiratory infections in preschool Inuit children. STUDY DESIGN: We reviewed the medical charts of 343 children from 0 to 5 years of age and evaluated the associations between PCB-153 concentration in umbilical cord plasma and the incidence rates of acute otitis media (AOM) and of upper and lower respiratory tract infections (URTIs and LRTIs, respectively). RESULTS: The incidence rates of AOM and LRTIs were positively associated with prenatal exposure to PCBs. Compared with children in the first quartile of exposure (least exposed), children in fourth quartile (most exposed) had rate ratios of 1.25 (p < 0.001) and 1.40 (p < 0.001) for AOM and LRTIs, respectively. There was no association between prenatal PCB exposure and incidence rate of URTIs or hospitalization. CONCLUSION: Prenatal exposure to PCBs could be responsible for a significant portion of respiratory infections in children of this population. [ABSTRACT FROM AUTHOR]

Most people in any community come into contact with chemicals that are potentially harmful to their health. Some elements are essential to health and inadequate amounts in food may also lead to ill health. Measurement of chemicals in blood, urine or other specimens is a fundamental feature of studies undertaken in the field of Occupational and Environmental Laboratory Medicine (OELM). Results are used to assess the risk for either overexposure or deficiency of essential nutrients. External Quality Assessment Schemes (EQAS) aid laboratories to achieve accurate and consistent data and 11 organisers of EQAS in Europe and North America are working to improve the effectiveness of their activities. The aims of the Network of EQAS Organisers in OELM are to stimulate improvements in analytical results, establish equivalence of assessment among Schemes, collaborate to enhance the practice of EQA including whenever possible to warrant traceability of EQAS to primary standards. [ABSTRACT FROM AUTHOR]

Quality specifications (QS) are proposed for lead in blood and for aluminium, copper, selenium and zinc in serum as part of the aim to set standards of performance for laboratories so that results can be demonstrated to be fit for the purpose to which they are applied. The QS were established taking account of the analytical state-of-the-art, physiological variations in the concentrations of the analyte and the clinical purpose for which the assay is to be used. A procedure was devised that uses these QS to give equivalence of assessment among external quality assessment schemes (EQAS), thus avoiding conflicting information which has been demonstrated in the past. Advantages of this procedure are: to provide direct comparison of performance of laboratories taking part in different schemes, to provide equivalence of assessment of laboratory performance necessary to establish mutual recognition agreements, and to demonstrate the fitness for purpose of results from participants. [ABSTRACT FROM AUTHOR]

Background: 1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) exposure has been demonstrated to cause liver tumors in laboratory rodents. DDT's persistent metabolite and environmental degradation product, 1,1-dichioro-2,2-bis(p-chlorophenyl)ethylene (DDE), has also been associated with liver tumors in laboratory animals. Whether DDT and DDE are associated with hepatocarcinogenesis in humans is not clear. Methods: We carried out a nested case-control study among the participants of the Nutritional Intervention Trials in Linxian, China. The case group included 168 individuals who developed liver cancer during the trials, and the control group included 385 individuals frequency-matched on age and sex who were alive and well at the end of the study. Serum concentrations of DDT and DDE were measured by gas chromatography-mass spectrometry. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable analysis. Results: In multivariable-adjusted models, the risk of developing liver cancer increased with increased serum DDT concentration (OR for quintile 1 versus quintile 5 = 3.8, 95% CI = 1.7 to 8.6, Ptrend = .0024). In contrast, there was no statistically significant association between liver cancer and serum DDE concentration. The association between high serum DDT concentration and liver cancer was stronger among individuals with DDE concentrations below the median value (odds ratio for tertile 3 versus tertile 1 = 3.55, 95% CI = 1.45 to 8.74) than those with concentrations above the median (OR = 1.70, 95% CI = 0.97 to 2.98). A calculation of crude liver cancer risk found that there would be 26 liver cancers per 100000 persons per year in the lowest quintile of DDT exposure versus 46 liver cancers per 100000 persons per year in the highest quintile of DDT exposure. Conclusions: DDT may be a risk factor for liver cancer, particularly among persons with lower DDE concentrations. Risk may be particularly increased among persons exposed directly to DDT (resulting in a higher ratio of DDT to DDE) or, alternatively, risk may be associated with individual ability to metabolize DDT to DDE. [ABSTRACT FROM AUTHOR]

Examines the effects of the organochlorine o,p'-dichlorodiphenyldichloroethane (o,p'-DDD) on the cortisol stress response in rainbow trout, Onchorhynchus mykiss, in a dose-response study in vivo. Effect of treatment with o,p'-DDD on weight gain, hematocrit and gonado- or hepatosomatic index.

Objective: This study was undertaken to evaluate the environmental exposure to polycyclic aromatic hydrocarbons (PAHs) in nonsmoking adult subjects living in the vicinity of a creosote impregnation plant in Delson, Canada. Urinary metabolites of naphthalene, α- and β-naphthol, and pyrene metabolite 1-hydroxypyrene (1-OHP), were used as biomarkers of exposure. Methods: Morning and evening urine samples were collected in mid-August from 30 exposed individuals living at a distance of 50–360 m downwind of the plant and from a control group in the adjoining municipality residing at a distance of 1.9–2.7 km upwind of the plant. Metabolites were measured by gas chromatography/mass spectrometry. Results: Excretion values of α- and β-naphthol were significantly higher in the exposed group than in controls (P < 0.04), after accounting for possible confounding variables by multivariate analyses. The respective geometric mean concentrations (5th and 95th percentiles) of α-naphthol for the exposed and nonexposed groups were 2.04 (0.55–6.00) and 1.37 (0.39–7.02) μmol/mol creatinine for evening samples, and 2.49 (0.77–8.43) and 1.17 (0.37–6.88) μmol/mol creatinine for morning samples. Corresponding values for β-naphthol were 1.78 (0.82–3.67) and 1.36 (0.63–5.07) μmol/mol creatinine for evening samples, and 1.94 (1.03–4.96) and 1.08 (0.49–5.05) μmol/mol creatinine for morning samples. On the other hand, no significant difference in 1-OHP excretion was observed between the exposed and the control group (P>0.5). The respective geometric mean concentrations (5th and 95th percentiles) of 1-OHP for these groups were 0.05 (0.01–0.17) and 0.06 (0.01–0.48) μmol/mol creatinine for evening samples, and 0.05 (0.02–0.12) and 0.05 (0.01–0.42) μmol/mol creatinine for morning samples. Conclusions: The measurement of α- and β-naphthol urinary concentrations appears to be an approach sufficiently sensitive to reveal differences in low exposure levels of volatile PAHs due to creosote impregnation plant emissions. However, uptake of pyrene due to the plant was too small to contribute significantly to 1-OHP excretion. [ABSTRACT FROM AUTHOR]

ABSTRACT. The authors conducted a survey during 1992 to evaluate blood levels of lead and mercury in Inuit adults of Nunavik (Arctic Québec, Canada). Blood samples obtained from 492 participants (209 males and 283 females; mean age = 35 yr) were analyzed for lead and total mercury; mean (geometric) concentrations were 0.42 μmol/l (range = 0.04–2.28 μmol/l) and 79.6 nmol/l (range = 4–560 nmol/l), respectively. Concentrations of omega-3 fatty acid in plasma phospholipids—a biomarker of marine food consumption—were correlated with mercury (r = .56, p < .001) and, to a lesser extent, with blood lead levels (r = .31, p < .001). Analyses of variance further revealed that smoking, age, and consumption of waterfowl were associated with lead concentrations (r² = .30, p < .001), whereas age and consumption of seal and beluga whale were related to total mercury levels (r² = .30, p < .001). A significant proportion of reproductive-age women had lead and mercury concentrations that exceeded those that have been reportedly associated with subtle neurodevelopmental deficits in other populations. [ABSTRACT FROM AUTHOR]

ABSTRACT. The authors evaluated lead exposure of Canadians (Montreal) who fished the nearby St. Lawrence River. From screening interviews conducted with 1,118 fishers on-site during the winter and fall of 1996, the authors selected 60 Montrealers who consumed at least one sportfish meal per week and 72 who consumed less than one sportfish meal per week. Fishers at the higher level of sportfish consumption had elevated blood lead concentrations, compared with fishers who ate little sportfish (geometric mean = 57.4 micro g/l vs. 48.2 micro g/l, respectively; p < .05). This result was surprising inasmuch as fish is not considered a significant source of lead. In addition to sportfish consumption, age, sex, occupation, smoking, and waterfowl consumption also showed independent associations with blood lead levels. Among frequent (i.e., 1 meal/wk) consumers of sportfish, ingestion of waterfowl was associated with higher blood lead levels (geometric mean = 69.4 micro g/l vs. 51.8 micro g/l, respectively; p < .05); this association was not present for infrequent consumers. In multivariate analysis, the association of higher blood lead levels with sportfish consumption could be accounted for in large part by waterfowl consumption among frequent consumers of sportfish. [ABSTRACT FROM AUTHOR]

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 subsample 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 µg/g lipids, standard deviation = 5.98) than among controls (mean = 2.51 µg/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. Am J Epidemiol 2000;152:363–70. [ABSTRACT FROM PUBLISHER]

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. [ABSTRACT FROM AUTHOR]

Examines the health risks involved in the exposure to mercury in French Guiana, which is used for gold extraction in that country. Evaluation of contamination among the general population; Number of subjects selected for testing; Observation of mean levels of mercury; What results of study indicates in relation to diet.

An abstract of the article " Polychlorinated biphenyls (PCB), UV radiation, and cutaneous malignant melanoma," by Richard P. Gallagher, Alain Leblanc, and Marilyn Borugian is presented.

Examines the effects of low-level lead and arsenic exposure on copper smelter workers in Quebec, Quebec. Conduction of cross-sectional medical examination of copper smelter workers; Characteristics of lead and arsenic distribution; Relationship between symptoms and lead and arsenic absorption.