Factors affecting serum vitamin a levels in matched maternal-cord pairs

Objective  To determine the relationship of various maternal and neonatal factors with serum vitamin A concentration in matched mother-newborn pairs. Methods  This is a cross-sectional study on 100 neonate-mother pairs at a tertiary care center at Raipur, C.G., India. Gestational age, birth weight and sex of the neonates as well as maternal parity, hemoglobin (Hb) levels, access to antenatal care (ANC) and presence of toxemia of pregnancy were recorded. Cord and maternal serum vitamin A levels were assayed. Results  Maternal serum vitamin A levels were not significantly affected by maternal age, parity, Hb level and presence of toxemia. Higher trend of maternal vitamin A concentrations (P=NS) and statistically higher values of cord serum vitamin A levels (P<0.05) were seen in mothers who had received ANC. Significantly higher cord vitamin A levels were seen with increasing weight of the placenta, birth weight of the newborn as well as its gestational age and maturity. Weak but significant positive correlation was present between maternal and cord serum vitamin A levels. Conclusion  Data from our study show that prematurity and intrauterine growth retardation are associated with low neonatal vitamin A levels. Several factors like lack of ANC, lower maternal Hb levels and reduced placental weight further affect vitamin A status of the newborn rendering them highly susceptible to vitamin A deficiency. We therefore, suggest further studies on vitamin A supplementation in pregnant women and preterm neonates.     

Blood lead levels and risk factors for lead toxicity in children from schools and an urban slum in Delhi

This cross-sectional study was conducted to estimate the mean blood lead levels (BLL) and prevalence of lead toxicity in a representative sample of schoolchildren and children residing in an urban slum. In addition, the association of potential environmental risk factors with elevated BLL was studied. Children aged 4-6 years were selected from schools of the South zone of Delhi (n = 125) and from an urban slum (n = 65). Risk factors were recorded using a pre-tested questionnaire and blood lead and zinc protoporphyrin (ZPP) levels were estimated. The mean BLL was 7.8 microg/dl (SD 3.9) and the proportion of children with blood lead > or = 10 microg/dl was 18.4 per cent. Distance of the residence or school from a main road appeared to be associated with higher blood lead concentrations, but these differences were not statistically significant. In our setting, vehicular pollution may be a major contributing factor in lead contamination of the environment.     

Blood lead levels in Omani children admitted to hospital

Whole blood lead levels were estimated by atomic absorption analysis in 119 Omani children admitted to hospital. Eighteen per cent of the children were found to have a blood lead level of 1.2 mumol/l or more, 5 per cent were found to have a level above 2.4 mumol/l and 3 per cent had very high levels in excess of 3.4 mumol/l. No overall relationship was demonstrated between age and blood lead levels. However, children less than 3 years old were three times more likely than those 3 years or above to have a blood lead level in excess of 2.4 mumol/l. The results of this study are sufficiently worrying to justify a more widespread community based survey of blood lead levels in Omani children.     

Blood lead levels of children with pica and surma use

Blood lead levels of 253 Delhi children were estimated by dithizone method. In 82 (controls) children with no symptoms mean blood lead level was 9.6 μg/dl (±SD 6.8: median 10 μg); only 6 had high levels between 30–33 μg/dl. In 88 children with pica, the mean blood lead level was 23.0 μg/dl (±SD 13.82; median 17 μg) which was significantly higher than the control; 26 had high levels between 30–92 μg/dl. Sixteen children with pica and surma- use and 46 children suspected of lead poisoning showed lead level patterns like the pica group. However, 21 surma-using children without pica resembled the control group. Children with pica were significantly more anemic than the controls and showed higher prevalence of abdominal-neurological symptoms. Because, in India, blood lead cannot be estimated in most of the hospitals, it is suggested that children with severe pica, anemia, abdominal-neurological symptoms and exposure to surma or lead, be suspected of lead poisoning, kept in lead-free environment with corrected nutrition, and be given a short cautious therapeutic trial with oral penicillamine.     

Effects of elevated blood lead levels in preschool children in urban Vellore

Objectives

To study the burden and associated risk factors for elevated blood lead levels among pre-school children (15–24 months) in urban Vellore, and to study its effects on child cognition and anemia.

Design

An investigative study through Mal-ED cohort.

Setting

Eight adjacent urban slums in Vellore, Tamil Nadu.

Participants

251 babies recruited through Mal-ED Network.

Outcome measures

Blood lead levels using Graphite Furnace Atomic Absorption Spectrophotometry method at 15 and 24 mo; hemoglobin estimation by azidemethemoglobin method; cognitive levels using Bayley Scales of Infant Development III.

Results

Around 45% of children at 15 months and 46.4% at 24 months had elevated blood lead levels (>10 μg/dL). Among children who had elevated blood lead levels at 15 months, 69.2% (45/65) continued to have elevated levels at 24 months. After adjusting for potential confounders, children from houses having a piped drinking water supply and houses with mud or clay floors were at significantly higher risk of having elevated blood lead levels at 15 months. Thirty one percent (21/67) of the children with elevated blood lead levels had poor cognitive scores. Children with elevated blood lead levels at 15 months had higher risk (Adjusted OR 1.80; 95% CI 0.80–3.99) of having poorer cognitive scores at 24 months. More than half of the children (57%) were anemic at 15 months of age, and elevated blood lead levels were not significantly associated with anemia.

Conclusions

Elevated blood lead levels are common among preschool children living in urban slums of Vellore. Poorer conditions of the living environment are associated with elevated lead levels.     

神经系统疾病儿童的血铅水平调查：单中心初步研究

目的：儿童铅中毒具有很大的潜在危害。慢性低水平铅暴露会导致学习障碍及行为问题,如腹痛,失眠,多动,生长发育落后,听力损失,上肢无力。该研究旨在调查神经系统疾病儿童的血铅水平,并与健康儿童作比较。方法：100名患有神经系统疾病的1~10岁儿童作为研究对象。100名年龄和性别匹配的健康儿童作为对照。采用火焰原子吸收光谱法检测血铅含量。结果：神经系统疾病组儿童的平均血铅含量显著高于对照组,差异有显著性 (113.2±47.5 μg/L vs 84.7±38.0 μg/L; P<0.01)。神经系统疾病组和对照组分别有44%和19%的儿童血铅超标（>100 μg/L）。结论：儿童血铅水平增高可能与神经系统疾病有关。建议对患神经系统疾病的儿童常规作血铅测定。［中国当代儿科杂志,2009,11（11）：873-876］     

神经系统疾病儿童的血铅水平调查:单中心初步研究(英文)

目的儿童铅中毒具有很大的潜在危害。慢性低水平铅暴露会导致学习障碍及行为问题,如腹痛,失眠,多动,生长发育落后,听力损失,上肢无力。该研究旨在调查神经系统疾病儿童的血铅水平,并与健康儿童作比较。方法100名患有神经系统疾病的1～10岁儿童作为研究对象。100名年龄和性别匹配的健康儿童作为对照。采用火焰原子吸收光谱法检测血铅含量。结果神经系统疾病组儿童的平均血铅含量显著高于对照组,差异有显著性(113.2±47.5μg/Lvs84.7±38.0μg/L;P<0.01)。神经系统疾病组和对照组分别有44%和19%的儿童血铅超标(>100μg/L)。结论儿童血铅水平增高可能与神经系统疾病有关。建议对患神经系统疾病的儿童常规作血铅测定。     

中国部分城市儿童血铅状况及其影响因素

目的 了解我国学前儿童血铅状况及其影响因素.方法 2004年起连续5年采用分层整群随机抽样法抽取银川、西安、成都、武汉、合肥、北京、长沙、哈尔滨、郑州、呼和浩特、石家庄、海口、大连、青岛、广州、南宁各城市相同城区固定幼儿园及社区的69 968名0～6岁儿童进行问卷调查,原子吸收法测定其血铅含量.结果 (1)5年儿童血铅含量≥100μg/L平均检出率为7.57%,血铅平均水平为(45.00±2.05)μg/L,均低于我国既往调查.2004-2008年儿童血铅含量≥100 μg/L检出率分别为10.03%、7.85%、7.40%、6.91%、4.78%(x2=297.36,P＜0.0001).2004-2008年儿童血铅平均含量≥100μg/L检出率海口12.15%、郑州10.49%、广州10.37%、石家庄9.69%、长沙9.53%、西安9.46%、武汉9.40%、合肥8.50%、成都7.99%、银川7.98%、哈尔滨7.51%、北京6.10%、大连3.25%、呼和浩特2.89%、南宁2.46%、青岛2.39%(x2=768.21,P＜0.0001).(2)Logistic回归分析:母亲文化程度低、儿童年龄大、常咬文具/玩具、男性、在交通繁忙地带散步/玩耍时间较长、进食前不洗手、常食爆米花、常服中草药、常吸吮手指啃指甲、住房楼层低、室内墙皮脱落、常玩橡皮泥、住所周围有油漆/蓄电池/炼钢铁/炼油/印刷厂、离主干道较近是其血铅含量≥100μg/L的危险因素.散居、常服钙、铁、锌制剂、常食乳类及乳制品、母亲年龄较大是保护因素(P＜0.05).结论 儿童血铅含量≥100 μg/L检出率高于发达国家,铅暴露是我国儿童的公共卫生问题.儿童血铅状况受外环境和自身多因素影响.政府及社会应以环境干预切断污染源为手段,以营养干预健康教育为方法,减少儿童铅暴露及其危害.

Abstract：

Objective To investigate the blood lead status and influencing factors among preschool children in the sampling city. Method Stratified-clustered-random sampling was used. Standardized questionnaire and peripheral blood samples were obtained from 69 968 children aged 0-6 years in fixed kindergartens and communities of Yinchuan, Xi'an, Chengdu, Wuhan, Hefei, Beijing, Harbin,Zhengzhou,Huhhot,Shijiazhuang,Haikou,Dalian,Qingdao,Guangzhou,Nanning and Changsha from 2004 to 2008,respectively.Tungsten atomic absorbtion spectrophotometry was employed to determine the blood lead level of children. Result The proportion of children with blood lead level ≥ 100 μg/L was 7.57%(among which the proportion of high blood lead level,mild lead poisoning,moderate lead poisoning,severe lead poisoning were 91.0% ,2.76% ,3.32% ,2.93%,respectively)and the blood leadlevel was lower than those of the past studies.The proportion of high blood lead level has steadily declined from 2004 to 2008 [the proportions were 10.03%,7.85%,7.40%,6.91% and 4.78%,respectively (x2 =297.36,P＜ 0.0001)].The proportion of children with blood lead level ≥ 100 μg/L in Haikou,Zhengzhou,Guangzhou,Shijiazhuang,Changsha ,Xi'an,Wuhan,Hefei,Chengdu,Yinchuan,Harbin,Beijing,Dalian,Huhhot,Nanning and Qingdao were 12.15%,10.49%,10.37%,9.69%,9.53%,9.46%,9.40%,8.50%,7.99%,7.98%,7.51%,6.10%,3.25%,2.89%,2.46% and 2.39%,respectively(x2 =768.21,P＜ 0.0001).By multiple regression method,the risk factors which influenced blood lead status of children were education status of mother,older children,behavior and dietary habit of children,boy,stay for long time in traffic busy areas,the type of housing,taking traditional Chinese and herbal medicine.The protective factors against lead poisoning in children mainly included scattered living,the nutritional status of calcium,iron,zinc,frequent intake of milk,and older mother.Conclusion The blood lead level of children has decreased,but is still higher than those in developed countries. Lead exposure remains a public health issue which affects children most. The blood lead level of children is affected by multiple factors. Government and the whole society should pay attention to interrupt the lead pollutant and to promote nutritional health education.With all these efforts,it is possible to stop the progress of lead exposure and reduce its hazardous effects on the growth and development of children.     

Blood lead and cadmium levels in children: A study conducted in Changchun,Jilin Province,China

OBJECTIVES:

Exposure to lead and cadmium in developing countries is considered to be a public health emergency. The present study was designed to investigate children’s exposure to lead and cadmium in Changchun, China.

METHODS:

A total of 1619 blood samples were collected at random from 1426 children between one and 14 years of age, and 204 adults from Changchun, China. Blood lead and cadmium levels were determined using atomic absorption spectrophotometry.

RESULTS:

The average blood lead level in children was 60.29 μg/L, with boys exhibiting higher blood lead levels than girls. The average blood cadmium level in children was 1.26 μg/L, and differences were not observed between boys and girls.

CONCLUSIONS:

Children from Changchun exhibited relatively low blood lead and cadmium levels compared with children from other cities, and higher lead and lower cadmium levels than adults. This may be related to leaded gasoline environmental pollution and children’s hand-to-mouth activities.     

Blood lead, calcium status, and behavior in preschool children

To determine if calcium status is associated with blood lead levels and behavior, 64 black urban children aged 18 to 47 months were studied. Twenty-seven controls (blood lead levels, less than 1.45 mumol/L) were compared with 37 cases (blood lead levels, greater than or equal to 1.45 mumol/L) with respect to four calcium measures (calcium intake, serum calcium level, 1,25-dihydroxyvitamin D level, and bone densitometric findings) and three behavioral scores. Levels of 25-hydroxyvitamin D provided a measure of vitamin D sufficiency. As expected, blood lead level was associated with pica scores. However, none of the calcium measures differed between cases and controls. Controlling for four confounders (season, pica score, maternal education, and sex), yielded no significant differences between the two groups in the mean values of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D level. There was no interaction between blood lead level and the four covariates. No relationship could be demonstrated between calcium status and the pica scores.     

Prevalence and hematological characteristics of beta-thalassemia trait in Gaziantep urban area, Turkey

Thalassemia is one of the most common hereditary disorders in the Mediterranean region and studies have shown that the prevalence of β-thalassemia trait is high in the southern part of Turkey. Gaziantep is a city located near this region and, therefore, the authors investigated the prevalence and hematological characteristics of the β-thalassemia traits in primary school students in Gaziantep. Sixty primary schools were selected from a list of all primary schools using a systematic sampling method. Data were collected by a face-to-face questionnaire. Osmotic fragility testing (OFT) using single-tube 0.36% NaCl solution was used for the screening of β-thalassemia. Students who were positive in regard to OFT went through a series of testing, including a complete blood count, serum ferritin levels, serum iron, and hemoglobin electroforesis. Chi-square test was used in statistical analysis. Of the 2439 students enrolled to the study from the selected 60 classrooms, 1353 (55.5%) were male and 1086 (44.5%) were female. The OFT was positive in 115 (4.7%) of the participants. CEA and confirmatory HPLC results of the students who were positive OFT indicated that 70 (60.8%) had normal results, 33(28.7%) showed high HbA2 levels, 7 (6.1%) showed high HbA2 and HbF levels, 5(5.2%) showed high HbA2 and Fe-deficiency anemia, and none showed increased HbF levels. The overall prevalence of β-thalassemia trait was 1.84%. No gender differentials and highest rates among the Kahramanmaras (3.5%) and Sanliurfa (1.7%) born students were the other significant findings of this study. Implementation of a routine carrier-screening program offering genetic counseling, prenatal diagnosis, and selective termination of affected fetuses would be a wise approach to eliminate this disease from the region.     

Blood lead and efythrocyte protoporphyrin levels in Kazakhstan

A pilot study was conducted to examine the extent of lead exposure and prevalence of iron deficiency in 3 major cities of Kazakhstan. Blood lead (B-Pb.) and erythrocyte protoporphyrin (ZnPP) levels of 475 children, age range 6 months to 7 yeas were measured. The mean B-Pb. levels in the different cities ranged from 4–7 ug/dl (minimum 1 to max 29 ug/dl) and similarly the mean ZnPP levels ranged from 26–32 ug/dl (minimum 12 and maximum 95 ug/dl), thus confirming low level lead poisoning of children at some sites. One to four year olds had greater than 10 ng/dl B-Pb in 18–27% cases compared with 3–7% cases in five to seven year olds. Prevalence of iron deficiency in 6 months to 4 year old children was the highest ranging from 28–86% compared with 4 to 15% in 4–7 year olds. However, there was remarkably low prevalence (4%) of iron deficiency in a group of 5–6 years olds. This study suggests that a targeted B-Pb and ZnPP monitoring together with an iron supplementation programme in the 3 cities of Kazakhstan is essential. Environmental education appears to have had a positive impact in lowering B-Pb at one site and should thus be expanded nationwide.     

兰州某厂两所幼儿园儿童血铅水平及其影响因素

为了解兰州市某厂两所幼儿园 (简称一幼、二幼 )3岁～6岁儿童血铅含量及其相关影响因素 ,于1998年6月至1999年1月对两所幼儿园的学龄前儿童 ,采用石墨炉原子吸收光谱法取外周微量血0.1ml,测定198名儿童的血铅水平 ,并在专人指导下 ,由父母及老师填写 :“儿童健康及行为问卷” ,该问卷内容包括 :家庭一般状况、家庭社会环境 ,儿童个人生活习惯及行为能力等共计46项。结果 :二幼小儿血铅含量 (113.83±51.20) μg/L明显高于一幼 (86.64±19.36) μg/L ,经t检验 (t=4.352 ,P<0.001)。二幼儿童血铅升高与家庭环境、社会环境、个人卫生习惯等诸多因素有相关性。提示 :家长和老师的双方教育、个人的卫生习惯直接影响血铅水平。所以 ,健康教育是有效、可行的铅中毒干预手段。     

Plasma lead levels in normal and lead-intoxicated children

Lead reaches tissues through the plasma, where the concentration of this ion is characteristically low. Little information exists on the mechanisms which determine the dynamics of lead in plasma. Measurement of plasma lead levels have been determined in normal and lead-intoxicated children, newborn infants, and children with sickle-cell disease. The results in all groups were remarkably similar and constant over a wide range of blood lead concentration and regardless of hematocrit. These results lend further support to the postulate that the red cell represents a repository for lead, maintaining plasma lead concentration within closely defined limits, and that methods other than an isolated measurement of plasma lead will be necessary to uncover a presumably dynamic transport system between red cell and plasma.     

Prevalence of beta-thalassemia and sickle cell anemia trait in premarital screening in Konya urban area, Turkey

Thalassemias and sickle cell anemia (SCA) are common disease in Turkey. To determine the prevalence of beta-thalassemia and SCA traits in Konya urban area of Turkey, all couples applied for marriage procedures were screened. Screening tests included complete blood count and quantitation of hemoglobin for both partners. The subjects were considered to have the beta-thalassemia trait if they had a mean corpuscular volume of less than 80 fL and/or a mean corpuscular hemoglobin level of less than 27 pg and a hemoglobin A2 level of more than 3.2% or a hemoglobin F level of more than 2%. Subjects were considered to have an SCA trait if they were positive for sickle hemoglobin. During the study, premarital screening of hemoglobinopathies was evaluated retrospectively in 72,918 subjects; the thalassemia trait was detected in 1465 subjects (2%), and the SCA trait was detected in 37 subjects (0.05%). Of the carriers of the beta-thalassemia trait, 820 (56%) people had high hemoglobin A2, 513 (35%) people had high hemoglobin F, and 132 (9%) people had both high hemoglobin F and hemoglobin A2. Our results are very similar to Turkey's beta-thalassemia and SCA trait averages.