广州市使用无铅汽油十年后儿童血铅水平调查

目的 通过检测现阶段儿童血铅水平,了解广州市使用无铅汽油10年后的实施效果.方法 按分层随机抽样方法从广州市12个区、县级市中取市中心区、城郊区和郊县各1个,每个区、县再按分层各抽4所幼儿园和4所小学,从中取2373名2至12岁自愿抽血检测的儿童为调查对象,每名儿童肘部抽取静脉血1～2 ml,用0.1%Triton X-100和0.1%HNO3,对血样稀释20倍后直接以电感耦合等离子体质谱仪(ICP-MS)测定血铅.结果 2373名儿童中血铅最高值为330μg/L,最小值为10μg/L,几何均值为58.28μg/L,男童血铅均值(61.11μg/L)高于女童(55.37μg/L)(t=8.671,P=0.000).高血铅儿童共60名,占2.51%,其中男童36名(2.90%),女童24名(2.09%),差异无统计学意义(X2=1.594,P=0.207).与10年前全国情况(铅中毒平均流行率50%～85%、血铅均值120～160μg/L)相比高血铅儿童流行率减少了96.25%,血铅平均水平下降了58.37%.城乡结合部的白云区血铅均值为60.33μg/L,明显高于市中心的荔湾区和增城(血铅均值分别为58.09、56.72μg/L).结论 广州市使用无铅汽油10年后儿童铅中毒和血铅水平均大幅下降.     

锌原卟啉作为环境铅污染人群筛查指标的可行性研究

目的探讨红细胞锌原卟啉（ZPP）应用于人群接触环境铅污染筛查指标的可行性。方法以紫金县某电池厂附近常住居民为调查对象,采集被调查者静脉血2～3 mL,采用血液锌原卟啉测定仪测定ZPP、石墨炉原子吸收光谱法测定血铅。儿童以血铅含量≥100μg/L、成年人以≥400μg/L为慢性铅中毒判定标准。结果共调查946名居民,其中1～13岁儿童174人、16～87岁成年人772人。儿童血铅含量超标率为14.9%（26/174）,儿童ZPP含量中位数为0.780μmol/L,血铅中位数为47.675μg/L,儿童ZPP含量与血铅含量的相关关系没有统计学意义（P〉0.05）。成人血铅含量超标率为9.5%（73/772）,成人ZPP含量中位数为0.740μmol/L,血铅中位数为69.572μg/L,成人ZPP含量与血铅含量呈弱相关关系（r=0.344,P〈0.05）。儿童血铅高水平组（血铅≥100μg/L）ZPP含量与血铅含量呈较强的相关关系（r=0.530,P〈0.05）,儿童血铅低水平组（血铅〈100μg/L）ZPP含量与血铅含量的相关关系没有统计学意义（P〉0.05）。成人血铅高水平组（血铅≥400μg/L）和低水平组（血铅〈400μg/L）的ZPP含量与血铅含量均具有相关关系（r分别为0.566、0.142,均P〈0.05）。结论成人血铅或儿童血铅水平较高时,ZPP可以作为环境铅污染人群筛查的指标。     

Association of low-level blood lead and blood pressure in NHANES 1999-2006

This study investigated whether low blood-lead levels (≤10 μg/dL) were associated with blood pressure (BP) outcomes. The authors analyzed data from National Health and Nutrition Examination Survey 1999-2006 and participants aged 20 years or older. Outcome variables were systolic and diastolic BP measurements, pulse pressure, and hypertension status. Multivariable linear and logistic regressions stratified by race/ethnicity and gender were performed. Blood lead levels (BLL) were significantly correlated with higher systolic BP among black men and women, but not white or Mexican-American participants. BLLs were significantly associated with higher diastolic BPs among white men and women and black men, whereas, a negative association was observed in Mexican-American men that had, also, a wider pulse pressure. Black men in the 90th percentile of blood lead distribution (BLL≥3.50 μg/dL) compared to black men in the 10th percentile of blood lead distribution (BLL≤0.7 μg/dL) had a significant increase of risk of having hypertension (adjusted POR=2.69; 95% CI: 1.08-6.72). In addition, blood cadmium was significantly associated with hypertension and systolic and diastolic blood. This study found that, despite the continuous decline in blood lead in the U.S. population, lead exposure disparities among race and gender still exist.     

Determinants of blood lead levels in children: a cross-sectional study in the Canary Islands (Spain)

The adverse effects of lead exposure on children are well known. Low blood lead levels (BLL) produce neurodevelopmental delay and cognitive disorders. However, since BLL thresholds for adverse effects on children's health are not known, the children population at risk of excessive lead exposure still has to be identified. This study was aimed at evaluating BLL in a children population of Gran Canaria (Canary Islands, Spain). Up to our knowledge, this is the first study to report on BLL in this population. Lead was identified and quantified in blood samples of 120 children, by means of Graphite furnace atomic absorption spectrometry (GFAAS). Lead was undetected in 80% of samples; BLL was 1 to 5 μg/dl in 15% of samples, and higher than 5 μg/dl in more than 4% of samples. BLL values in the evaluated children were low and similar to those described for other populations in Western countries. However, samples with the highest contamination (those in percentile 95) reached BLLs as high as 5.2 μg/dl. Positive associations were found between BLL and recent immigration (children adopted from non-western countries), and between BLL and parental smoking in children with low weight at birth. Since lead exposure in childhood may be a causative factor in adverse health trends - especially those involving the neurological system - and since threshold values for adverse lead effects are unknown, our finding that around 20% of the studied children had BLL higher than 1 μg/dl are of concern. Enhancing preventive measures for reducing lead exposure in children from the Canary Islands deserves further study.     

Reduction of elevated blood lead levels in children in North Carolina and Vermont, 1996-1999

BACKGROUND: Few studies have examined factors related to the time required for children's blood lead levels (BLLs) > or = 10 microg/dL to decline to < 10 microg/dL. OBJECTIVES: We used routinely collected surveillance data to determine the length of time and risk factors associated with reducing elevated BLLs in children below the level of concern of 10 microg/dL. METHODS: From the North Carolina and Vermont state surveillance databases, we identified a retrospective cohort of 996 children < 6 years of age whose first two blood lead tests produced levels > or = 10 microg/dL during 1996-1999. Data were stratified into five categories of qualifying BLLs and analyzed using Cox regression. Survival curves were used to describe the time until BLLs declined below the level of concern. We compared three different analytic methods to account for children lost to follow-up. RESULTS: On average, it required slightly more than 1 year (382 days) for a child's BLL to decline to < 10 microg/dL, with the highest BLLs taking even longer. The BLLs of black children [hazard ratio (HR) = 0.84; 95% confidence interval (CI), 0.71-0.99], males (HR(male) = 0.83; 95% CI, 0.71-0.98), and children from rural areas (HR(rural) = 0.83; 95% CI, 0.70-0.97) took longer to fall below 10 microg/dL than those of other children, after controlling for qualifying BLL and other covariates. Sensitivity analysis demonstrated that including censored children estimated a longer time for BLL reduction than when using linear interpolation or when excluding censored children. CONCLUSION: Children with high confirmatory BLLs, black children, males, and children from rural areas may need additional attention during case management to expedite their BLL reduction time to < 10 microg/dL. Analytic methods that do not account for loss to follow-up may underestimate the time it takes for BLLs to fall below the recommended target level.     

Blood lead levels of refugee children resettled in Massachusetts, 2000 to 2007

Objectives. We described elevated blood lead level (BLL; ≥ 10 μg/dL) prevalence among newly arrived refugee children in Massachusetts. We also investigated the incidence of BLL increases and BLLs newly elevated to 20 μg/dL or higher in the year following initial testing, along with associated factors.Methods. We merged data from the Massachusetts Department of Public Health''s Refugee and Immigrant Health Program and the Childhood Lead Poisoning Prevention Program on 1148 refugee children younger than 7 years who arrived in Massachusetts from 2000 to 2007.Results. Elevated BLL prevalence was 16% among newly arrived refugee children. The rate ratio for BLL elevation to 20 μg/dL or higher after arrival was 12.3 (95% confidence interval [CI] = 6.2, 24.5) compared with children in communities the state defines as high-risk for childhood lead exposure. Residence in a census tract with older housing (median year built before 1950) was associated with a higher rate of BLL increases after resettlement (hazard ratio = 1.7; 95% CI = 1.2, 2.3).Conclusions. Refugee children are at high risk of lead exposure before and after resettlement in Massachusetts. A national surveillance system of refugee children''s BLLs following resettlement would allow more in-depth analysis.Refugee children who resettle in the United States may arrive with substantially higher blood lead levels (BLLs) than those among children in the general US population.^1,2 For recently arrived refugees, the risk of additional lead exposure after immigration may also be substantial. In 2000, a 2-year-old Sudanese refugee child died as a result of exposure to lead in her family''s New Hampshire home.³ A subsequent case series among children resettled in New Hampshire raised concerns that African refugee children may be at particularly high risk of lead exposure. In that study, 22 of 71 children (31%) who arrived without an elevated BLL (≥ 10 μg/dL) had an elevated BLL at follow-up testing, indicating new exposure to lead after immigration.²Preventing postimmigration lead exposure among refugee children is an important public health priority because of the irreversible behavioral and cognitive deficits caused by even low levels of lead exposure in early childhood.⁴ Families may be placed in housing with inherently high health risks—generally older, nonrehabilitated housing with lead exposure hazards from deteriorating paint or contaminated soil. Such families may also have difficulty accessing health care over time, so cases of lead poisoning may not be identified. To prevent lead exposure and its adverse consequences in refugee children, information regarding the sources of lead, its prevalence, and the severity of exposure is necessary.Our primary goal was to describe the risk of elevated BLLs among refugee children upon arrival in the United States and in the period following resettlement. Secondary goals were to determine whether African origin was associated with an increased risk of elevated BLL at initial and follow-up testing and whether residence in housing built prior to 1950 (after which use of lead in residential paint declined) was associated with postimmigration increases in BLL.     

Association between children's blood lead levels, lead service lines, and water disinfection, Washington, DC, 1998-2006

Objective

Evaluate the effect of changes in the water disinfection process, and presence of lead service lines (LSLs), on children’s blood lead levels (BLLs) in Washington, DC.

Methods

Three cross-sectional analyses examined the relationship of LSL and changes in water disinfectant with BLLs in children <6 years of age. The study population was derived from the DC Childhood Lead Poisoning Prevention Program blood lead surveillance system of children who were tested and whose blood lead test results were reported to the DC Health Department. The Washington, DC Water and Sewer Authority (WASA) provided information on LSLs. The final study population consisted of 63,854 children with validated addresses.

Results

Controlling for age of housing, LSL was an independent risk factor for BLLs ≥10 μg/dL, and ≥5 μg/dL even during time periods when water levels met the US Environmental Protection Agency (EPA) action level of 15 parts per billion (ppb). When chloramine alone was used to disinfect water, the risk for BLL in the highest quartile among children in homes with LSL was greater than when either chlorine or chloramine with orthophosphate was used. For children tested after LSLs in their houses were replaced, those with partially replaced LSL were >3 times as likely to have BLLs ≥10 μg/dL versus children who never had LSLs.

Conclusions

LSLs were a risk factor for elevated BLLs even when WASA met the EPA water action level. Changes in water disinfection can enhance the effect of LSLs and increase lead exposure. Partially replacing LSLs may not decrease the risk of elevated BLLs associated with LSL exposure.     

Demographic and socioeconomic factors associated with blood lead levels among Mexican-American children and adolescents in the United States

OBJECTIVE: This study was designed to assess demographic and socioeconomic differences in blood lead levels (BLLs) among Mexican-American children and adolescents in the United States. METHODS: We analyzed data from the Third National Health and Nutrition Examination Survey, 1988-1994, for 3,325 Mexican-American youth aged 1 to 17 years. The main study outcome measures included a continuous measure (microg/dL) of BLL and two dichotomous measures of BLL (> or =5 microg/dL and > or =10 microg/dL). RESULTS: The mean BLL among Mexican-American children in the United States was 3.45 microg/dL (95% confidence interval [CI] 3.07, 3.87); 20% had BLL > or =5 microg/dL (95% CI 15%, 24%); and 4% had BLL > or =10 microg/dL (95% CI 2%, 6%). In multivariate analyses, gender, age, generational status, home language, family income, education of head of household, age of housing, and source of drinking water were statistically significant independent predictors (p<0.05) of having higher BLLs and of having BLL > or =5 microg/dL, whereas age, family income, housing age, and source of drinking water were significant predictors (p<0.05) of having BLL > or =10 microg/dL. CONCLUSIONS: Significant differences in the risk of having elevated BLLs exist among Mexican-American youth. Those at greatest risk should be prioritized for lead screening and lead exposure abatement interventions.     

Blood lead levels in the adult Victorian population: results from the Victorian Health Monitor

Objective : To estimate blood lead levels (BLLs) in the adult Victorian population and compare the distribution of BLLs with the current national reference level to better inform public health prevention and management of lead toxicity. Methods : Population‐based cross‐sectional health measurement survey of 50 randomly selected Census Collection Districts (CDs) throughout Victoria. The Victorian Health Monitor (VHM) was conducted over 12 months from May 2009 to April 2010. One eligible person (aged 18–75 years) from each household selected within each CD was randomly selected to participate. Persons with an intellectual disability and pregnant women were excluded from the sampling frame. BLLs were obtained from 3,622 of the 3,653 (99%) VHM participants. Results : The geometric mean and median BLLs from the adult sample were 0.070 μmol/L (95%CI, 0.068–0.073) and 0.05 μmol/L (range: 0.05 to 1.22 μmol/L), respectively. Elevated BLLs (≥0.483 μmol/L or ≥10 μg/dL) were identified in 19 participants (0.7%; 95%CI, 0.3–1.6). Additionally, 86 participants (1.8%; 95%CI, 1.3–2.4) were identified with BLLs between 0.242 and <0.483 μmol/L (5 to <10 μg/dL). The geometric mean BLL was significantly higher for males, compared with females (0.077 μmol/L vs 0.064 μmol/L; p<0.001). BLLs increased significantly with age for both sexes. Conclusions : The first population estimates of BLLs in Victorian adults indicate the average adult BLL to be well below the current national reference level. However, some groups of the population have BLLs at which adverse effects may occur. Implications : The results provide baseline estimates for future population health surveillance and comparison with studies of at‐risk groups.     

Blood Lead Levels and Serum Insulin-Like Growth Factor 1 Concentrations in Peripubertal Boys

Background: Childhood lead exposure has been associated with growth delay. However, the association between blood lead levels (BLLs) and insulin-like growth factor 1 (IGF-1) has not been characterized in a large cohort with low-level lead exposure.Methods: We recruited 394 boys 8–9 years of age from an industrial Russian town in 2003–2005 and followed them annually thereafter. We used linear regression models to estimate the association of baseline BLLs with serum IGF-1 concentration at two follow-up visits (ages 10–11 and 12–13 years), adjusting for demographic and socioeconomic covariates.Results: At study entry, median BLL was 3 μg/dL (range, < 0.5–31 μg/dL), most boys (86%) were prepubertal, and mean ± SD height and BMI z-scores were 0.14 ± 1.0 and –0.2 ± 1.3, respectively. After adjustment for covariates, the mean follow-up IGF-1 concentration was 29.2 ng/mL lower (95% CI: –43.8, –14.5) for boys with high versus low BLL (≥ 5 μg/dL or < 5 μg/dL); this difference persisted after further adjustment for pubertal status. The association of BLL with IGF-1 was stronger for mid-pubertal than prepubertal boys (p = 0.04). Relative to boys with BLLs < 2 μg/dL, adjusted mean IGF-1 concentrations decreased by 12.8 ng/mL (95% CI: –29.9, 4.4) for boys with BLLs of 3–4 μg/dL; 34.5 ng/mL (95% CI: –53.1, –16.0) for BLLs 5–9 μg/dL; and 60.4 ng/mL (95% CI: –90.9, –29.9) for BLLs ≥ 10 μg/dL.Conclusions: In peripubertal boys with low-level lead exposure, higher BLLs were associated with lower serum IGF-1. Inhibition of the hypothalamic–pituitary–growth axis may be one possible pathway by which lead exposure leads to growth delay.     

Childhood Lead Exposure After the Phaseout of Leaded Gasoline: An Ecological Study of School-Age Children in Kampala,Uganda

Background

Tetraethyl lead was phased out of gasoline in Uganda in 2005. Recent mitigation of an important source of lead exposure suggests examination and re-evaluation of the prevalence of childhood lead poisoning in this country. Ongoing concerns persist about exposure from the Kiteezi landfill in Kampala, the country’s capital.

Objectives

We determined blood lead distributions among Kampala schoolchildren and identified risk factors for elevated blood lead levels (EBLLs; ≥ 10 μg/dL).

Analytical approach

Using a stratified, cross-sectional design, we obtained blood samples, questionnaire data, and soil and dust samples from the homes and schools of 163 4- to 8-year-old children representing communities with different risks of exposure.

Results

The mean blood lead level (BLL) was 7.15 μg/dL; 20.5% of the children were found to have EBLL. Multivariable analysis found participants whose families owned fewer household items, ate canned food, or used the community water supply as their primary water source to have higher BLLs and likelihood of EBLLs. Distance < 0.5 mi from the landfill was the factor most strongly associated with increments in BLL (5.51 μg/dL, p < 0.0001) and likelihood of EBLL (OR = 4.71, p = 0.0093). Dust/soil lead was not significantly predictive of BLL/EBLL.

Conclusions

Lead poisoning remains highly prevalent among school-age children in Kampala. Confirmatory studies are needed, but further efforts are indicated to limit lead exposure from the landfill, whether through water contamination or through another mechanism. Although African nations are to be lauded for the removal of lead from gasoline, this study serves as a reminder that other sources of exposure to this potent neurotoxicant merit ongoing attention.     

Blood lead levels in children after phase-out of leaded gasoline in Kinshasa,the capital of Democratic Republic of Congo (DRC)

Background

The phasing out of lead from gasoline has resulted in a significant decrease in blood lead levels (BLLs) in children during the last two decades. Tetraethyl lead was phased out in DRC in 2009. The objective of this study was to test for reduction in pediatric BLLs in Kinshasa, by comparing BLLs collected in 2011 (2 years after use of leaded gasoline was phased out) to those collected in surveys conducted in 2004 and 2008 by Tuakuila et al. (when leaded gasoline was still used).

Methods

We analyzed BLLs in a total of 100 children under 6 years of age (Mean ± SD: 2.9 ± 1.6 age, 64% boys) using inductively coupled argon plasma mass spectrometry (ICP – MS).

Results

The prevalence of elevated BLLs (≥ 10 μg/dL) in children tested was 63% in 2004 [n = 100, GM (95% CI) = 12.4 μg/dL (11.4 – 13.3)] and 71% in 2008 [(n = 55, GM (95% CI) = 11.2 μg/dL (10.3 – 14.4)]. In the present study, this prevalence was 41%. The average BLLs for the current study population [GM (95% CI) = 8.7 μg/dL (8.0 – 9.5)] was lower than those found by Tuakuila et al. (F = 10.38, p <0.001) as well as the CDC level of concern (10 μ/dL), with 3% of children diagnosed with BLLs ≥ 20 μg/dL.

Conclusion

These results demonstrate a significant success of the public health system in Kinshasa, DRC-achieved by the removal of lead from gasoline. However, with increasing evidence that adverse health effects occur at BLLs < 10 μg/dL and no safe BLLs in children has been identified, the BLLs measured in this study continue to constitute a major public health concern for Kinshasa. The emphasis should shift to examine the contributions of non-gasoline sources to children’s BLLs: car batteries recycling in certain residences, the traditional use of fired clay for the treatment of gastritis by pregnant women and leaded paint.     

Lead poisoning associated with malaria in children of urban areas of Nigeria

The principal objectives of this study are to (a) investigate the prevalence of elevated blood lead levels (EBLLs) in children of three major cities of Nigeria with different levels of industrial pollution; (b) identify the environmental, social and behavioral risk factors for the EBLLs in the children; and (c) explore the association between malaria (endemic in the study areas) and EBLLs in the pediatric population. The study involved 653 children aged 2-9 years (average, 3.7 years). The mean blood lead level (BLL) for the children was 8.9+/-4.8mug/dL, the median value was 7.8mug/dL, and the range was 1-52mug/dL. About 25% of the children had BLL greater than 10mug/dL. There were important differences in BLLs across the three cities, with the average value in Ibadan (9.9+/-5.2mug/dL) and Nnewi (8.3+/-3.5mug/dL) being higher than that in Port Harcourt (4.7+/-2.2mug/dL). Significant positive associations were found between BLL and a child's town of residence (p<0.001), age of the child (p=0.004), length of time the child played outside (p<0.001), presence of pets in a child's home (p=0.023), but negatively with educational level of caregiver (p<0.001). This study is one of the first to find a significant negative association between BLL and malaria in a pediatric population, and this association remained significant after controlling for confounding diseases and symptoms. The shared environmental and socio-demographic risks factors for lead exposure and Plasmodium (most common malaria parasites) infection in urban areas of Nigeria are discussed along with possible ways that lead exposure may influence the host response to infection with malarial parasites.     

Relationship Between Prenatal Lead Exposure and Infant Blood Lead Levels

Recent literature has shown that analyzing newborn dried blood spots (DBS) may be effective in assessing some prenatal environmental exposures, such as exposure to lead. The purpose of this study was to evaluate the relationship between prenatal exposure to lead (as measured by newborn DBS results) and blood lead levels (BLLs) in infants 6?months of age or younger, using public health registry data for infants born in Texas from July 2002 through July 2006. The Texas Child Lead Registry (TCLR) was used to identify infants with documented elevated BLLs of 10?μg/dL or higher as well as infants with documented low BLLs. BLLs for these children were compared to their corresponding newborn DBS results using Pearson correlation coefficients and exact logistic regression models. Overall, a significant but weak positive correlation was found between infant BLLs and corresponding newborn DBS lead levels (r?=?0.48). However, the odds of an infant with an elevated newborn DBS lead level having an elevated BLL at 6?months of age or younger were much greater than for an infant with a low newborn DBS lead level of <5?μg/dL (adjusted odds ratio 27.95, 95% CI: 5.52-277.28). Although an association was observed between newborn DBS lead levels and BLLs in infants tested between 0 to 6?months of age, our findings suggest that prenatal exposure may not be the only significant source of lead exposure for infants ≤6?months of age.     

Death of a child after ingestion of a metallic charm--Minnesota, 2006

Lead-based paint remains the most common source of lead exposure for children aged <6 years. However, one report determined that 34% of children aged <6 years with lead poisoning in Los Angeles County had been exposed to items containing lead that had been brought into the home. These items might include candy, folk and traditional medications, ceramic dinnerware, and metallic toys and trinkets. Exposures to some of these items can result in life-threatening BLLs of > or =100 microg/dL (elevated BLLs are > or =10 microg/dL for children and > or =25 microg/dL for adults). In 2004, a child in Oregon had a BLL of 123 microg/dL after ingesting a necklace with high lead content. The same year, the Consumer Product Safety Commission (CPSC) recalled 150 million pieces of imported metallic toy jewelry sold in vending machines. Some lead-contaminated items intended for use by children are manufactured in countries with limited government regulation of lead in consumer products. With the decline in BLLs in U.S. children, widespread education of the dangers of lead paint, and systematic reduction of lead hazards in U.S. housing, acute ingestion of lead-containing items has become increasingly more common as a source of life-threatening BLLs.     

Lead Poisoning Among Arab American and African American Children in the Detroit Metropolitan Area,Michigan

This study explored the hypothesis that acculturation is a risk factor for childhood lead poisoning in the Detroit area of Michigan. Blood lead levels (BLLs) were determined in 429 Arab American and African American children, aged 6 months to 15 years, who were receiving well-child examination in three Women, Infant, and Children (WIC) clinics in the city. Mean BLL was 3.8 ± 2.3 μg/dL (range: 1–18 μg/dL) and 3.3% of the children tested had blood lead values above the 10 μg/dL level of concern. Neither the age of the dwelling units nor ethnicity of the child was significantly associated with the BLL. Multivariable analyses instead identified a number of acculturation-related factors that are associated with elevation in blood lead including paternal education, language spoken at home (English only, English and Arabic, or Arabic only), home ownership, smoking in the home, and exposure of child to home health remedies. The difference in blood lead between Arab American children from families where Arabic only versus Arabic and English is spoken at home was found to be statistically significant. This study provides information showing that immigrant children are at heightened risk of being poisoned by lead which can be useful in identifying groups at risk of atypical exposures.     

低水平铅暴露儿童的GH/IGF-1轴变化及其与ALAD基因多态性的关系

目的:探讨低水平铅暴露儿童的生长激素/胰岛素样生长因子-1(GH/IGF-1)轴的变化及其与δ-氨基-γ-酮戊酸脱氢酶(ALAD)基因多态性的关系。方法:用钨舟原子吸收光谱法测定来自深圳市区242例学龄前儿童静脉血铅水平(BLL)。按血铅水平将患儿分为两组,A组BLL<50μg/L,B组BLL≥50μg/L。对两组对象的身高(H)、血红蛋白水平(Hb)、ALAD基因、生长激素(GH)、胰岛素样生长因子-1(IGF-1)和胰岛素样生长因子结合蛋白-3(IGFBP-3)水平进行比较。身高测量和血红蛋白检测用常规方法进行;ALAD基因多态性检测采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)法;生长激素测定采用化学发光法;IGF-1和IGFBP-3测定采用ELISA法。结果:242例儿童的血铅水平范围为8～146μg/L,几何均数47μg/L。BLL≥50μg/L者占43%,≥100μg/L者占0.8%。两组儿童的IGFBP-3水平差异有统计学意义,B组明显低于A组。身高和IGF-1略有差异,但无统计学意义。基因多态性分析显示,223例为ALAD1-1型,19例为ALAD1-2型,未发现ALAD2-2型。ALAD2基因出现的频率为7.85%。两组儿童突变基因的频率分布差异无统计学意义。结论:本研究发现即使低水平铅暴露也与儿童血IGFBP-3水平明显降低有关,表明铅中毒损害儿童GH/IGF-1轴功能。在低水平铅暴露状态下,ALAD基因的多态性对儿童血铅水平并无明显影响。可能只有在高水平铅暴露时,ALAD基因变异才会对儿童铅中毒易感性发挥作用。     

Childhood correlates of blood lead levels in Mumbai and Delhi

BACKGROUND: Lead exposure has previously been associated with intellectual impairment in children in a number of international studies. In India, it has been reported that nearly half of the children have elevated blood lead levels (BLLs). However, little is known about risk factors for these elevated BLLs. METHODS: We conducted a retrospective cross-sectional analysis of data from the Indian National Family Health Survey, a population-based study conducted in 1998-1999. We assessed potential correlates of BLLs in 1,081 children who were < 3 years of age and living in Mumbai or Delhi, India. We examined factors such as age, sex, religion, caste, mother's education, standard of living, breast-feeding, and weight/height percentile. RESULTS: Most children (76%) had BLLs between 5 and 20 microg/dL. Age, standard of living, weight/height percentile, and total number of children ever born to the mother were significantly associated with BLLs (log transformed) in multivariate regression models. Compared with children < or = 3 months of age, children 4-11 and 12-23 month of age had 84 and 146% higher BLLs, respectively (p < 0.001). A low standard of living correlated with a 32.3% increase in BLLs (p = 0.02). Children greater than the 95th percentile for their weight/height had 31% (p = 0.03) higher BLLs compared with those who were below the 5th percentile for their weight/height. CONCLUSIONS: Our study found various factors correlated with elevated BLLs in children. The correlation between greater than the 95th percentile weight/height and higher BLL may reflect an impact of lead exposure on body habitus. Our study may help in targeting susceptible populations and identifying correctable factors for elevated BLLs in Mumbai and Delhi.     

Resurgent lead poisoning and renewed public attention towards environmental social justice issues: A review of current efforts and call to revitalize primary and secondary lead poisoning prevention for pregnant women,lactating mothers,and children within the U.S.

The recent Colorado Gold King Mine waste-water spill and Michigan’s water supply re-routing program catastrophe, has directed renewed public attention towards resurgent environmental lead contamination threats. Leaded environments present social justice issues for children and mothers possessing blood lead levels (BLLs) > 5 μg/dL. Childhood lead exposure remains a continual U.S. public health problem manifesting in lifelong adverse neuropsychological consequences. The 2007 Inspector General Report demonstrated low BLL screening rates across the U.S. and this study examined the regularity of children’s BLL screening rates. The Centers for Disease Control and Prevention (CDC) Lead Poisoning National Surveillance 2010–2014 children’s BLL screening rates, were examined to assess BLL screening regularity in states traditionally known to have regularly occurring BLL screenings: New York, New Jersey, and Pennsylvania. The results extracted from the CDC data showed that < 50% of children were BLL screened by six-years of age across the states that were sampled. The findings highlight that without a “clear map” of lead exposed areas through accurate and consistent BLL screenings, how the potential for such disparities within – and between-states within the U.S. could arise due to environmental social justice issues in relation to BLL screening barriers. Barriers preventing children’s BLL screenings were considered, and public health interventions recommended to improve screening rates included: routine BLL screening for all pregnant women, lactating mothers, and children; while, removing known lead exposure sources within communities. This study calls for action during a time of renewed public attention to resurgent lead poisoning within the U.S.     

Elevated Blood Lead Levels Among Fire Assay Workers and Their Children in Alaska, 2010–2011

In October 2010, an employee at Facility A in Alaska that performs fire assay analysis, an industrial technique that uses lead-containing flux to obtain metals from pulverized rocks, was reported to the Alaska Section of Epidemiology (SOE) with an elevated blood lead level (BLL) ≥10 micrograms per deciliter (μg/dL). The SOE initiated an investigation; investigators interviewed employees, offered blood lead screening to employees and their families, and observed a visit to the industrial facility by the Alaska Occupational Safety and Health Section (AKOSH). Among the 15 employees with known work responsibilities, 12 had an elevated BLL at least once from October 2010 through February 2011. Of these 12 employees, 10 reported working in the fire assay room. Four children of employees had BLLs ≥5 μg/dL. Employees working in Facility A''s fire assay room were likely exposed to lead at work and could have brought lead home. AKOSH inspectors reported that they could not share their consultative report with SOE investigators because of the confidentiality requirements of a federal regulation, which hampered Alaska SOE investigators from fully characterizing the lead exposure standards.Occupational lead exposure continues to threaten workers'' health.^1–3 In the United States, the Occupational Safety and Health Administration (OSHA) prescribes standards for permissible exposure limits for lead in the workplace and specifies that a blood lead level (BLL) of 40 micrograms per deciliter (μg/dL) triggers more frequent (i.e., every two months rather than every six months) blood lead testing. OSHA standards require that workers with a BLL ≥60 μg/dL, or an average BLL for the last three tests or all tests during the previous six months (whichever is longer) of ≥50 μg/dL, be removed from the lead exposure area, unless the most recent test indicated a BLL ≤40 μg/dL.⁴ However, research has increased concern regarding lead toxicity at lower doses and has supported a reevaluation of the level at which BLLs can be considered safe.⁵ The National Institute for Occupational Safety and Health (NIOSH) defines an elevated BLL in an adult as ≥10 μg/dL.⁶ In addition to adverse impacts on the health of the workers themselves, children of lead-exposed workers have disproportionately higher BLLs when compared with other children.^7–9Elevated BLLs among adults are associated with muscle and joint pain, reproductive problems, and neurologic symptoms, including memory loss.¹⁰ Negative health effects have been observed among adults with only modestly elevated BLLs,^11–13 with increased odds of an ill effect occurring at levels as low as 1.6–2.4 μg/dL.¹¹ Among children, elevated BLLs can result in devastating health effects, including brain and nervous system damage, slow growth, and hearing problems.¹⁰ Research indicates that there is no safe level of lead among children.¹⁴ Despite considerable data on the deleterious health effects of lead regarding both children and adults, harmful occupational exposures that are inadequately controlled continue to put workers and their families at risk. A BLL of ≥5 μg/dL is the reference level that the Advisory Committee on Childhood Lead Poisoning Prevention has recommended to identify children with elevated BLLs.¹⁴ Elevated BLLs ≥10 μg/dL for children and adults are reportable in Alaska under Alaska Administrative Code 27.014.¹⁵