Biomedical subjects
Publications and source records attributed to E Nieboer.
The authors evaluate possible use of Monchegorsk retrospective birth database for demographic and epidemiologic studies of various female reproductive health parameters, newborn health parameters, as well as their connections with occupational and other environmental factors.
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Bismuth shotshells have been approved as a "nontoxic" alternative to lead in North America. Approval was based on a limited number of studies; even background levels of bismuth in wildfowl were unknown. We report on the concentration of bismuth (and lead) in muscle and liver tissues of wildfowl (Anas platyrhynchos, Anas acuta, Anas crecca, Branta canadensis, Chen caerulescens) harvested with lead shotshell. Average liver-bismuth levels detected in the present study (e.g., teal, 0.05 microg/g dw; mallard, 0.09 microg/g dw) suggest analytical error in other studies examining the effects of bismuth in birds. Significant positive relationships between bismuth- and lead-tissue levels for muscle when all species were combined (and for B. canadensis and C. caerulescens separately) can be explained by noting that bismuth is a contaminant of lead. Thus, more research is recommended to confirm the appropriateness of bismuth as a "nontoxic" shot alternative.
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Research is described that constitutes an extension of an earlier paper (J. Environ. Monit., 2001, 3, 177-184), in which concentrations were measured in 263 human placentas of 11 essential elements (P, Ca, Mg, Cu, S, Na, Fe, Zn, K, Se, Mn) and 5 toxic elements (Ba, Sr, Pb, Ni, Cd). The additional data considered derive from earlier visits to 4 of the original 6 communities and 3 others, all but one of which are located in northern Norway and neighbouring areas of Russia. This more than doubled the number of placental samples available (263 to 571). Unfortunately, the personal, life-style and morphometric information obtained for the first study group was not available for the additional mothers. Country differences were evident for all elements except Ba, Fe and Zn; Cd, Cu, Mn, Na, Se, Ni, Pb, Sr and S were higher and K, P, Ca and Mg were lower in Russia (p < 0.03). Not unexpectedly, the highest median lead concentration was observed for the largest city in the western arctic region of Russia, namely Murmansk. Similarly, the higher median nickel level observed for Russia reflects the established observation that urinary nickel concentrations are higher in the Russian than in the Norwegian communities. Even though sampling was performed at different times of the year and before and after a 3-year interval in four centres, inter-collection differences were of relatively small magnitude and appear not to be linked to seasonal or temporal changes. Principal component analysis (PCA) confirmed the prominence of Factor 1, which grouped those metals that are known to form insoluble phosphate complexes and whose concentrations showed a dependence on gestational age and maternal smoking in the earlier study. It is concluded that PCA is a powerful statistical tool for exploring and identifying fundamental pathways and processes involved in governing the inorganic elemental composition of placental tissue. It also has the potential of identifying study limitations and quality assurance shortfalls. Further our findings show promise that placental concentrations of toxic elements may serve as an index of exposure and of nutritional intake for selected essential micro-elements.
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Concentrations in human placenta of 11 essential elements (P, Ca, Mg, Cu, S, Na, Fe, Zn, K, Se, Mn) and 5 toxic elements (Ba, Sr, Pb, Ni, Cd) are compared for each of two arctic communities in eastern Norway and western Russia, and for another in each country located at more southerly latitudes. All but Mg, Fe, P and K were present in higher concentrations in the Russian study group. The observed inter-element correlations are reflected by the four major factors identified in a principal component analysis. The total variation explained was 67.3%, of which more than half (35.3%) was contributed by Factor 1. P, Ca, Mg, Ba, Sr, Pb, and Ni were major contributors to this factor. The placental concentrations of these elements depended strongly on gestational age, increasing from about week 35 and peaking near weeks 39 and 40, and exhibited skewed frequency distributions and a dependence on maternal smoking. The gestational-dependent mineralization of the placenta is interpreted to reflect the deposition of metal phosphates coinciding with smoking-induced tissue damage. The loadings of the remaining three factors are reviewed in the context of common uptake mechanisms, similar biochemistries and unique transport pathways. The inter-element relationships and grouping of the elements observed should constitute a scientific base for the use of placenta composition in environmental monitoring and epidemiological studies.
Teeth were collected from First Nation schoolchildren inhabiting the remote western James Bay region of northern Ontario, Canada. Lead levels in dentine chips were determined by graphite furnace atomic absorption spectrometry, for naturally exfoliated deciduous teeth. Within exfoliated teeth (one tooth supplied per person), no significant differences in lead concentrations between tooth type were found (P = 0.36). The mean lead concentration of exfoliated teeth of 9.2 microg g(-1) dry weight (N = 61) from this remote region was comparable to levels reported by others for children inhabiting urban centers or residing near smelters. Further, 24.6% (N = 15) had elevated dentine-lead levels ( > 10 microg g(-1)). Lead levels in soil, water, and air have been reported as being low and unimportant sources of exposure for people of the western James Bay area. Evidence is reviewed suggesting that lead contaminated game meat was one source of environmental lead exposure. Consumption data indicate that wildlife is still an important food source for First Nation people of the western James Bay region; 98% (46/47) of the children surveyed consumed some type of wild meat.
Individual aerosol particles (n = 1170) collected at work stations in a nickel refinery were analyzed by wavelength-dispersive electron-probe microanalysis. By placing arbitrary restrictions on the contents of sulfur and silicon, the particles could be divided into four main groups. Scanning electron images indicated that most of the particles examined were relatively small (< or = 2 microm, equivalent projected area diameter), and that their morphology suggested formation from a melt. There was an absence of well-defined phases and simple stoichiometries, indicating that exposures to pure substances such as nickel subsulfide or specific oxides appeared not to occur. Although the elemental composition of particles varied greatly, a rough association was evident with the known elemental content of the refinery intermediates. The implications of the findings for aerosol speciation measurements, toxicological studies and interpretation of adverse health effects are explored.
BACKGROUND: The feasibility study described herein was prompted by a report in 1992 of possible reproductive and developmental health concerns among female workers in a Russian nickel refinery. OBJECTIVE: The primary goal was to ascertain whether medical, statistical, and occupational data bases could be accessed for information about the pregnancy histories, occupational histories, and life-style factors of the women affected. METHODS: The project was facilitated by construction of a registry of all births in three towns with a nickel refinery and verification of its contents against patients' records obtained from hospital delivery and gynecology departments and community polyclinics. Municipal Registration Board, Regional Health Statistics Board, and nickel company records were also reviewed. RESULTS: Reproductive/developmental outcome information and workplace histories were acceptable. Sample-size calculations indicated that a cohort or cross-sectional study would be amenable and suitable for the detection of an excess risk for spontaneous abortion with adequate statistical significance and power. Such investigations would need to be supplemented by workplace environmental/biological monitoring assessments for evaluation of exposure to occupational hazardous factors and a worker's questionnaire to obtain information about life-style factors. A case-control design is recommended for the study of congenital defects. CONCLUSIONS: A well-designed, comprehensive epidemiology study is technically feasible because of the availability of a favorable pool of study subjects, reproductive/developmental outcome data, information to control for major confounders, and suitable occupational records.
In support of a feasibility study of reproductive and developmental health among females employed in the Monchegorsk (Russia) nickel refinery, personal exposure and biological monitoring assessments were conducted. The inhalable aerosol fraction was measured and characterised by chemical speciation and particle-size distribution measurements. Unexpected findings were that: (i), pyrometallurgical working environments had significant levels of water-soluble nickel; (ii), significant exposure to cobalt occurred for the nickel workers; (iii), particles of size corresponding to the thoracic and respirable fractions appeared to be virtually absent in most of the areas surveyed. The water-soluble fraction is judged to be primarily responsible for the observed urinary nickel and cobalt concentrations. It is concluded relative to current international occupational-exposure limits for nickel in air, and because of the high nickel concentrations observed in urine, that the Monchegorsk nickel workers are heavily exposed. The implication of this finding for follow-up epidemiological work is alluded to.
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The two objectives of this study were to compare urinary nickel excretion in pregnant women and their newborns living in the Murmansk and Arkhangelsk Counties of Russia with that in comparable Norwegian populations living in Finnmark and the city of Bergen and to assess the influence on pregnancy outcome of different risk variables, specifically urinary nickel concentrations and questionnaire-based anamnestic information. Life-style information and urine samples were collected from 50 consecutive mother-infant pairs from hospital delivery departments in three Russian and three Norwegian communities. Pregnancy outcomes were verified from medical records. Urinary nickel excretion was significantly higher in the Russian communities, independent of the presence of a nickel refinery as a local environmental source. The birth weight and mean body mass index of the newborn children (BMIC) were significantly lower (p < 0.001) in the Russian groups, with or without adjustment for gestational age. A multivariate linear regression analysis indicated that maternal urinary nickel concentration had no impact on birth weight. The maternal body mass index (BMI) and maternal height were positive explanatory variables; maternal urinary creatinine is suggested as a weak negative factor. Smoking was shown to be a strong negative predictor only in the Norwegian group among whom there was a significantly higher smoking frequency (p = 0.005). The significant contribution of a country factor in the predictive model is interpreted to indicate that a number of important risk factors for low birth weight were not identified.
This paper is the result of an investigation carried out in February 1997, which set out to learn about the development and application of occupational health standards, and in turn approaches to occupational environmental monitoring, in Russia, and to see how these were similar to, or different from, what takes place in other countries. The enquiry involved face-to-face meetings with senior Russian occupational health scientists and officials. It was confirmed that Russian occupational exposure standards are very stringent and provide a very high level of protection of workers. However, they are difficult to enforce, and it is suggested that the development of a strong and distinctive occupational hygiene discipline and profession in Russia would provide a "bridge" to enable more effective implementation and interpretation of those standards.
UNLABELLED: As part of the Arctic Monitoring and Assessment Programme (AMAP), we assessed pregnancy outcome among Sami and Norwegian populations of Finnmark County in Norway and Russians living in the Kola Peninsula of Russia using body mass index of the newborn child (BMIC) as the main indicator; concentrations of essential and toxic elements in biological fluids of delivering women and their children served as additional sources of information. At the hospitals of Hammerfest and Kirkenes in the period November 1993-June 1994 a total of 107 consecutive women gave birth to a child, of whom 15 regarded themselves as Sami. The Russian group (N = 151) delivered their children in the same period. The Sami women were significantly older than the Russian group (28.5 versus 25.1 years, p = 0.04). The mean birth weight was significantly lower in the Sami group compared to non-Sami Norwegians (p = 0.01), but was of comparable magnitude to that recorded in Russia (p = 0.4). For BMIC, the Sami and non-Sami Norwegian results were similar (p = 0.2); both were significantly higher than in Russia (p < 0.001). The essential elements copper, zinc, selenium and iron (as ferritin) in serum showed no differences between the groups, although relatively low levels of serum zinc were documented in all populations studied. Blood cadmium concentrations were strongly related to smoking frequency. Blood lead and urinary nickel levels were significantly higher for the Russian mothers, but did not reach levels of medical concern. CONCLUSION: No ethnic differences in concentrations of essential elements in biological fluids, nor of cadmium and mercury, were observed. However, national differences for lead and nickel were evident. Because of small sample size, these conclusions need confirmation. The similar BMIC values observed for the non-Sami Norwegian and Sami newborns, compared to the Russian group, suggest that BMIC may serve as a good indicator of the nutritional status and possibly also the general health condition of neonates.