Exposure of the Inuit population of Nunavik (Arctic Quebec) to lead and mercury

The authors conducted a survey during 1992 to evaluate blood levels of lead and mercury in Inuit adults of Nunavik (Arctic Quebec, 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 micromol/l (range = 0.04-2.28 micromol/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.     

Association between gestational night blindness and serum retinol in mother/newborn pairs in the city of Rio de Janeiro, Brazil

OBJECTIVE: Gestational night blindness (XN) is associated with increased risk of reproductive morbidity and mortality. This study investigated the prevalence of gestational XN among postpartum women treated in a public maternity hospital in the city of Rio de Janeiro, Brazil and evaluated its association with maternal and neonatal (cord blood) serum retinol concentrations. METHODS: XN was evaluated retrospectively, using an interview according to guidelines of the World Health Organization, in 222 postpartum women (< or = 6 h after delivery) after singleton births who had low obstetric risk. Serum retinol concentrations were measured according to the modified Bessey method, with a cutoff point lower than 1.05 micromol/L for inadequate serum retinol concentration. RESULTS: Prevalence of gestational XN was 18%, and inadequate maternal and cord blood serum retinol concentrations were found in 24.4% and 45.5% of samples, respectively. The results associated gestational XN with inadequate maternal serum retinol concentration (P = 0.000), and an association was observed between maternal and neonatal serum retinol concentrations (P = 0.000). A poor association was observed between maternal XN and serum levels of retinol in newborn children (P = 0.06). CONCLUSIONS: The results suggest that prevalence of gestational XN and inadequate serum retinol concentration among postpartum women and newborns is a concern, calling attention to the need for studies in other parts of Brazil. In addition, the risk of inadequate serum retinol in newborns was significantly higher among infants of postpartum women with serum retinol levels below 1.05 micromol/L. Gestational XN was associated with inadequate levels of maternal serum retinol, and the results suggest a poor relation between maternal XN and vitamin A nutritional status of newborns.     

产妇及新生儿血铅水平调查

目的:了解佛山市产妇、新生儿血铅水平及其影响因素。方法:采用电感耦合高频等离子体发射光谱法,于2003年6月～2004年2月,取本院产科产妇静脉血及其新生儿脐血588例,进行血铅、钙、锌、铁、铜和锰水平测定,按妇幼保健管理卡内容,进行相关记录。结果:产妇血铅水平0.424±0.170μmol/L,Bpb≥0.483μmol/L者占19.05％,新生儿脐血铅水平0.417±0.164μmol/L,铅中毒率为18.71％;母子血铅值显著正相关(r=0.861,P<0.01),产妇血铅值与其血钙、铁值显著负相关(r=-0.267、-0.298,P<0.05);城郊产妇及新生儿血铅水平显著高于城区。结论:城郊产妇、新生儿血铅较高,血钙、锌、铁含量影响血铅水平。     

Prevalence of elevated blood lead levels and evaluation of a lead-risk-screening questionnaire in rural Minnesota

The objectives of the study reported here were to determine the prevalence of elevated blood lead levels in rural Minnesota and to evaluate a lead-risk-screening questionnaire. Blood lead tests and lead risk questionnaires were obtained for a sample of 1,090 children younger than 48 months of age (72 percent of the eligible population) from three rural counties of west-central Minnesota between September 1, 2001, and August 31, 2002. It was found that overall, 2.4 percent of children in the study had blood lead levels of > or = 10 microg/dL (0.48 micromol/L) (results for capillary and venous tests combined), 0.9 percent had venous blood lead levels of > or = 10 microg/dL, and 0.5 percent of study participants had blood lead levels of > or = 20 microg/dL (0.96 micromol/L). Three risk factor questions, when taken together, predicted 90 percent of blood lead levels of > or = 10 microg/dL and all blood lead levels of > or = 20 microg/dL. The study estimated the prevalence of lead poisoning using a sample of the entire population rather than a clinic-based convenience sample. The authors conclude that targeted screening is an effective way to identify lead-poisoned children in rural areas of Minnesota.     

Influence of exposure to environmental lead on serum immunoglobulin in preschool children

Serum immunoglobulin (IgG, IgM, and IgE) concentrations of 38 preschool children with blood lead levels > or = 0.48 pmol/L (10 microg/ dL) were examined and compared to 35 preschool children with blood lead levels < or = 0.48 micromol/L. No differences in serum concentrations of IgG, IgM, and IgE in the populations were observed, but IgG, IgM, and IgE of male and female children from the high blood lead level group were compared to those of controls and the results showed that IgG and IgM were significantly lower in the high blood lead level group of females than in the controls, while IgE was significantly higher in the high blood lead level group of females than in the controls (P < 0.05). No correlation between blood lead concentration and serum immunogloblins IgG and IgM was demonstrated, but a statistically significant relationship between IgE and blood lead level was found in this population. These data indicate that the effect of lead on IgG, IgM, and IgE was stronger in females than in males and lead could play a role in this process by stimulating IgE production.     

Concentrations of ascorbic acid in the plasma of pregnant smokers and nonsmokers and their newborns

A cross-sectional study was carried out to determine the differences in vitamin C status of Brazilian pregnant women smokers and nonsmokers and their respective newborn babies, and to assess the prevalence of hypovitaminosis C among these two groups of women. The study involved 127 pregnant women, 40 pregnant smokers and 87 pregnant nonsmokers, admitted to a maternity hospital in S?o Paulo, Brazil. Data concerning the pregnant women's socioeconomic, demographic, obstetric, and nutritional characteristics were collected, as well as data concerning the newborns' anthropometry and Apgar scores. A strongly significant correlation (p < 0.001) was found between the concentrations of ascorbic acid (AA) in both pregnant smokers (r = 0.77) and pregnant nonsmokers (r = 0.61) and their respective umbilical cords. The mean umbilical AA concentration was significantly higher than the meanAA concentration in pregnant women (92.05 +/- 41.13 vs. 33.39 +/- 18.25 micromol/L, p < 0.001). It was observed that the mean AA was significantly lower for the newborns (p = 0.03) and pregnant women (p = 0.02) from the smoking group. Forty percent (40%) of the smokers and 27% of the nonsmokers presented hypovitaminosis C. We suggest an increase in the consumption of fruits and vegetables by pregnant women, especially the smokers.     

妊娠晚期邻苯基苯酚暴露与新生儿体格指标的关系

目的 探讨孕妇妊娠晚期尿中邻苯基苯酚(o-phenylphenol,OPP)水平与新生儿出生体格指标之间联系。方法 选取某县1 100对孕妇-新生儿,采集孕妇分娩前尿样并完成调查问卷,测定尿中OPP浓度,结合新生儿体格指标进行统计分析。结果 孕妇尿中OPP的检出率为100%,中位值为0.35 μg/L,肌酐校正后中位值为0.54 μg/g,暴露水平稍高于国外类似研究报道。广义线性模型分析显示,孕妇尿中OPP肌酐校正浓度对数可能与新生儿出生身长(β=-0.670,P=0.006)及头围(β=-0.505,P=0.001)呈一定的负相关。按新生儿性别分层后,OPP水平可能与男童身长、体重及头围呈一定程度的负相关(P<0.05),而女童则未发现任何相关。结论 该地区孕妇普遍暴露于OPP,其妊娠晚期OPP水平可能与男性新生儿出生身长、体重及头围呈一定负相关。     

Blood lead, calcium, and phosphorus in women with preeclampsia in Edo State, Nigeria

The authors investigated the effect of blood lead (BPb) and its relationship with calcium and phosphorus in the development of preeclampsia in Nigeria. Blood samples were collected from 59 preclamptics, 150 normal pregnant, and 122 nonpregnant women. Blood lead and serum Ca and P were determined. Blood lead was significantly higher (p < .001), whereas serum Ca and P were significantly lower (p < .001) in preclamptics than in normal pregnant women (60.2 ± 12.8 vs 26.3 ± 8.0 μg/dL for Pb, 1.39 ± 0.33 vs 2.03 ± 0.22 mmol/L for Ca, and 0.76 ± 0.10 vs 0.99 ± 0.13 mmol/L for P, respectively). There was significant increase (p < .05) in BPb and decreases (p < .01) in serum Ca and P in pregnant women than in nonpregnant women (35.7 ± 18.0 vs 13.1 ± 6.4 μg/dL for Pb, 1.85 ± 0.33 vs 2.33 ± 0.20 mmol/L for Ca, and 0.93 ± 0.38 vs 1.24 ± 0.26 mmol/L for P). Also, BPb was negatively correlated with serum Ca and, P, and positively correlated with systolic and diastolic blood pressures in pregnancy (r = -.804 for Ca, r = -.728 for P, r = .908 for SBP, and r = .842 for DBP) and preeclampsia (p < .01). It appears that increase in blood lead, which parallels decreases in serum calcium and phosphorus, may be related to the development and progression of preeclampsia in this environment.     

Monitoring of umbilical cord blood lead levels and sources assessment among the Inuit

Analyses completed on samples collected between 1993 and 1996 showed that about 7% of 475 Inuit newborns from northern Quebec (Canada) had a cord blood lead concentration equal to or greater than 0.48 micromol/l, an intervention level adopted by many governmental agencies. A comparison between the cord blood lead isotope ratios of Inuit and southern Quebec newborns showed that lead sources for these populations were different. Our investigation suggests that lead shots used for game hunting were an important source of lead exposure in the Inuit population. A cohort study conducted in three Inuit communities shows a significant decrease of cord blood lead concentrations after a public health intervention to reduce the use of lead shot. Lead shot ammunition can be a major and preventable source of human exposure to lead.     

The night vision threshold test is a better predictor of low serum vitamin A concentration than self-reported night blindness in pregnant urban Nepalese women

This study was conducted to validate the night vision threshold test (NVTT) as an indicator of night blindness. A total of 1401 pregnant women from the National Maternity Hospital participated in this study. Women were queried about night blindness and took the NVTT using standardized procedures after 10 min of dark adaptation. Sixteen percent failed the NVTT, but only 6.4% reported having night blindness. Blood samples from women who failed the NVTT (cases) and matched controls indicated the serum vitamin A (SVA) concentration was lower (P < 0.05) in cases (1.19 +/- 0.03 micromol/L) than in controls (1.29 +/- 0.03 micromol/L). The SVA concentrations did not differ between women who reported and did not report night blindness. The SVA concentration was correlated (r = 0.22, P < 0.001) with the NVTT scores. Twenty-five percent of women with an SVA < 0.35 micromol/L reported night blindness while 100% failed the NVTT. Nineteen percent of women with an SVA < 0.70 micromol/L reported night blindness while 73% failed the NVTT. A receiver operating characteristics analysis indicated that the NVTT had greater sensitivity (0.73 vs. 0.19) and less specificity (0.51 vs. 0.87) compared with reported night blindness for women with SVA < 0.70 micromol/L and greater sensitivity (100.0 vs. 0.73) and similar specificity (0.51 vs. 0.50) for women with SVA < 0.35 micromol/L. The NVTT identified women with low SVA and self-reported night blindness was misleading. We provide a preliminary algorithm to predict the population of women with low SVA concentrations.     

Relationship between increased blood lead and pregnancy hypertension in women without occupational lead exposure in Tehran, Iran

This study was conducted to assess the relationship between blood lead levels and pregnancy-induced hypertension. Participants were 110 pregnant women, of whom 55 were hypertensive, 27 +/- 5.6 yr of age (mean +/- standard deviation) (range = 17-40 yr); the other 55 women were age- and gravidity-matched normotensive controls. Participants were selected on the basis of their medical history and the results of a questionnaire-based interview. Subjects were at gestational ages 37 +/- 2.5 wk (range = 30-41 wk) and were not occupationally exposed to lead. Blood samples were collected within 24 hr after delivery, and blood lead levels were measured. For the hypertensive cases, blood lead levels were 5.7 +/- 2 microg/dl (range = 2.2-12.6 microg/dl [0.27 +/- 0.10 micromol/l; range = 0.11-0.60 micromol/l]), which were significantly higher than those of the control group (i.e., 4.8 +/- 1.9 microg/dl; range = 1.9-10.6 microg/dl [0.23 +/- 0.09 micromol/l; range = 0.09-0.51 micromol/l]). There were no significant differences in blood lead concentrations among hypertensive subjects with proteinuria (n = 30) and those without proteinuria (n = 25). Results of this study indicated that low-level lead exposure may be a risk factor for pregnancy hypertension.     

Vitamin A status of pregnant Nigerian women: relationship to dietary habits and morbidity

Vitamin A status of pregnant Nigerian women has been determined by measurement of retinol concentration in plasma samples obtained from pregnant subjects, using a spectrophotometric method. The relationship between vitamin A status, dietary habits and morbidity pattern was also examined. Two hundred (200) consecutive pregnant women registered for antenatal clinic at the Obafemi Awolowo University Teaching Hospitals Complex within a period of eight (8) weeks were recruited as subjects. The subjects were aged 15-43 years (mean 27.2 years), and were at different stages of pregnancy. Semi-structured questionnaires were administered on the subjects to obtain data on dietary habits, present health status and obstetric history. Vitamin A deficiency (plasma retinol concentration < 0.35 micromol/L) is found in 17.5% of the subjects, while 37% and 45.5% have borderline (plasma retinol concentration 0.35-0.70 micromol/L) and normal (plasma retinol concentration > 0.70 micromol/L) vitamin A status respectively. There is a significant relationship between frequent micturition and vitamin A status (chi-square = 0.39: P < 0.05). There is no relationship between maternal age and vitamin A status. Although about 80% of the subjects consumed red palm oil daily, about 64% would heat the oil to smoking for at least 10 minutes, before adding to stew during cooking. Green vegetables were also boiled in hot water before adding to sauce, while liver is consumed on just about three days per month. The findings reported in this study have further strengthened the claim that vitamin A deficiency is fairly prevalent in pregnant Nigerian women, underlining the need for prompt and effective intervention.     

铁剂对缺铁孕妇和新生儿干预作用的研究

目的 :　研究孕妇缺铁导致新生儿缺铁的发病情况和补充铁剂的干预作用。方法 :　 44例孕妇分为对照组和铁剂组 ,孕中期开始分别服用安慰剂或铁剂。分别测定孕妇在服药前、服药后及新生儿的各项铁指标 :血清铁 (serum iron,SI)、总铁结合力 (total iron binding capacity,TIBC) ,转铁蛋白饱和度 (transferrin saturation,TS) ;血清铁蛋白 (serum ferritin,SF)。血红蛋白(Hb)值为临床资料。结果 :　对照组新生儿 Hb、SI、TS、SF平均值均低于铁剂组新生儿 ;对照组新生儿贫血发病率和贮铁不足率达 80 %、54.5% ,明显高于铁剂组。除母血 SF与新生儿 SI以外 ,孕妇与新生儿的 SI、TS、SF之间呈不同程度的显著正相关。孕末期铁剂组孕妇缺铁性贫血人数明显少于对照组 ;对照组孕妇孕末期 Hb、SI、TS、SF较孕中期进一步降低或维持原来的低水平 ,而铁剂组孕妇孕末期 Hb、SI、TS较孕中期有增加 ,SF未进一步降低。结论 :　孕妇与新生儿的铁营养状况密切相关 ,孕妇缺铁会导致新生儿缺铁。补充铁剂能减少孕妇及其新生儿缺铁     

Maternal plasma ascorbic Acid (vitamin C) and risk of gestational diabetes mellitus

BACKGROUND: Antioxidants, particularly vitamin C (ascorbic acid), have the capacity to influence glucose tolerance. Modification of diet could reduce the likelihood of developing gestational diabetes mellitus. METHODS: In a prospective cohort study of pregnant women, we studied the association of maternal plasma ascorbic acid concentrations, measured at an average of 13 weeks' gestation, with subsequent risk of gestational diabetes. Maternal plasma ascorbic acid concentrations were determined using automated enzymatic procedures. Dietary vitamin C intake during the periconceptional period and early pregnancy was ascertained using a semiquantitative food frequency questionnaire. We fitted generalized linear models to derive estimates of relative risks and 95% confidence intervals (CIs). RESULTS: Approximately 4% (n = 33) of 755 women who completed pregnancy developed gestational diabetes mellitus. Plasma ascorbic acid concentrations were inversely associated with the risk of gestational diabetes (P for trend = 0.023). After adjusting for maternal age, race, prepregnancy adiposity, parity, family history of type 2 diabetes, and household income, women with plasma ascorbic acid <55.9 micromol/L (lowest quartile) experienced a 3.1-fold increased risk of gestational diabetes (95% CI = 1.0 - 9.7) compared with women whose concentrations were > or = 74.6 micromol/L (upper quartile). Women who consumed <70 mg vitamin C daily experienced a 1.8-fold increased risk of gestational diabetes compared with women who consumed higher amounts (95% CI = 0.8 - 4.4). CONCLUSIONS: If confirmed, our results raise the possibility that current efforts to encourage populations to consume diets rich in antioxidants, including vitamin C, could reduce the occurrence of gestational diabetes mellitus.     

Comparison of urinary and plasma cotinine levels during the three trimesters of pregnancy

Assays of metabolised cotinine are considered to be an accurate measure of exposure to cigarette smoke among pregnant women. We investigated the association and differences between the cotinine levels in maternal urine and blood, and the umbilical cord blood of three tobacco exposure groups at different stages of pregnancy. A prospective study was conducted among 398 pregnant women undergoing prenatal care in different trimesters at two medical centres and one regional hospital in central Taiwan. All 398 subjects (including 25 smokers, 191 passive smokers and 182 non-smokers) remained in the study up to the time of delivery; 384 of them delivered singleton live births. Cotinine levels were assayed in the maternal plasma and urine of the mothers at each trimester and in the cord blood of the newborns. All specimens were measured using a sensitive high-performance liquid chromatography. Cotinine concentrations in plasma and urine showed a significant dose-dependent difference among the three groups (non-smoker, passive and active smoker) and a trend that increased with gestation among the pregnant women. Significant correlations between cotinine concentrations in plasma and urine among the pregnant women in each trimester were found. In addition, the level of cotinine in umbilical cord blood was significantly correlated with that in maternal blood at term (r = 0.89, P < 0.001). A pattern of elevated cotinine concentrations in the plasma and urine of pregnant women from the beginning to the end of pregnancy was found, and this correlated significantly with the cotinine levels in the umbilical cord blood.     

Oxidative Stress at Birth Is Associated with the Concentration of Iron and Copper in Maternal Serum

Oxidative stress (OS) in the foetal and neonatal periods leads to many disorders in newborns and in later life. The nutritional status of pregnant women is considered to be one of the key factors that triggers OS. We investigated the relationship between the concentration of selected mineral elements in the blood of pregnant women and the concentration of 3′nitrotyrosine (3′NT) as a marker of OS in the umbilical cord blood of newborns. The study group consisted of 57 pregnant women and their newborn children. The concentrations of magnesium (Mg), calcium (Ca), iron (Fe), zinc (Zn) and copper (Cu) in maternal serum (MS) were measured by the flame atomic absorption/emission spectrometry (FAAS/FAES) method. The concentration of 3′NT in umbilical cord serum (UCS) of newborns was determined by the ELISA method. A positive correlation between MS Fe and UCS 3′NT in male newborns was shown (rho = 0.392, p = 0.053). Significantly higher UCS 3′NT was demonstrated in newborns, especially males, whose mothers were characterized by MS Fe higher than 400 μg/dL compared to those of mothers with MS Fe up to 300 μg/dL (p < 0.01). Moreover, a negative correlation between the MS Cu and UCS 3′NT in male newborns was observed (rho = −0.509, p = 0.008). Results of the study showed the need to develop strategies to optimize the nutritional status of pregnant women. Implementation of these strategies could contribute to reducing the risk of pre- and neonatal OS and its adverse health effects in the offspring.     

Serum selenium levels in Saudi new-borns

Selenium (Se) was measured in 300 umbilical cord blood samples collected from healthy pregnant women who live in Al-Kharj area in Saudi Arabia by means of Inductively Coupled Plasma Spectrometry with the hydride t-system. The selenium concentration found in the serum of 300 newborns was 40.847 ± 8.969 μpg/L. Preterm infants had significantly lower serum selenium concentrations than full-term infants (32 ± 8.029 μg/L versus 41.323 ± 8.784 μg/L). Significant positive correlations were found between selenium levels and birth weight. Results of this study suggest that low selenium levels of new-borns in Al-Kharj may reflect an inadequate maternal dietary intake.     

Dietary and biochemical selenium status of urban 6- to 24-month-old South Island New Zealand children and their postpartum mothers

A community-based, cross-sectional survey was conducted in the South Island of New Zealand to assess the dietary and biochemical selenium status of children (n = 136) and their mothers (n = 302), and to assess factors influencing selenium status. Serum and plasma samples from children and their mothers were analyzed for selenium using graphite furnace atomic absorption spectrometry. Dietary selenium intakes were analyzed from 3-d weighed diet records, and food sources of selenium were quantified. Mean dietary selenium intakes in infants (6-11.9 mo), toddlers (12-24 mo), and mothers were below recommended levels. Toddlers had higher selenium intakes than infants (13.7 +/- 8.4 and 7.9 +/- 6.2 microg/d, respectively, P = 0.0001) and the selenium density of their diets was also higher [3.2 +/- 1.7 and 2.4 +/- 1.7 microg/(MJ . d), respectively, P = 0.003]. Household smoking was associated with lower serum selenium concentrations in infants and toddlers (P = 0.02). South Island women who were currently pregnant had lower plasma selenium concentrations (0.74 +/- 0.15 micromol/L) than nonpregnant lactating and nonpregnant nonlactating women (0.94 +/- 0.16 and 0.93 +/- 0.16 micromol/L, respectively, P = 0.0001). Clearly, pregnant women, infants and toddlers are at risk of suboptimal selenium status, and further research is warranted to assess potential effects in these groups. The finding of an association between household smoking and lower selenium concentrations in children should be investigated further. Dietary interventions are recommended to improve dietary selenium intakes in South Island children and their mothers.