Geometric Mean Blood Lead Levels Research Articles

Mapping Blood Lead Levels in China during 1980-2040 with Machine Learning.

Lead poisoning is globally concerning, yet limited testing hinders effective interventions in most countries. We aimed to create annual maps of county-specific blood lead levels in China from 1980 to 2040 using a machine learning model. Blood lead data from China were sourced from 1180 surveys published between 1980 and 2022. Additionally, regional statistical figures for 15 natural and socioeconomic variables were obtained or estimated as predictors. A machine learning model, using the random forest algorithm and 2973 generated samples, was created to predict county-specific blood lead levels in China from 1980 to 2040. Geometric mean blood lead levels in children (i.e., age 14 and under) decreased significantly from 104.4 μg/L in 1993 to an anticipated 40.3 μg/L by 2040. The number exceeding 100 μg/L declined dramatically, yet South Central China remains a hotspot. Lead exposure is similar among different groups, but overall adults and adolescents (i.e., age over 14), females, and rural residents exhibit slightly lower exposure compared to that of children, males, and urban residents, respectively. Our predictions indicated that despite the general reduction, one-fourth of Chinese counties rebounded during 2015-2020. This slower decline might be due to emerging lead sources like smelting and coal combustion; however, the primary factor driving the decline should be the reduction of a persistent source, legacy gasoline-derived lead. Our approach innovatively maps lead exposure without comprehensive surveys.

Lead occurrence in North Carolina well water: importance of sampling representation and collection techniques

Private wells often lack centralized oversight, drinking water quality standards, and consistent testing methodologies. For lead in well water, the lack of standardized data collection methods can impact reported measurements, which can misinform health risks. Here, we conducted a targeted community science testing of 1143 wells across 17 counties in North Carolina (USA) and compared results to state testing data primarily associated with new well construction compiled in the NCWELL database. The goal of our study was to explore the impacts of sampling methodology and household representation on estimated lead exposures and subsequent health risks. At the household scale, we illustrated how sampling and analytical techniques impact lead measurements. The community science testing first draw samples (characterizing drinking water) had a 90th percentile lead value of 12.8 μg l−1 while the NCWELL database flushed samples (characterizing groundwater) had a value below the reporting level of 5 μg l−1. As lead was associated with the corrosion of premise plumbing, flushing prior to collection substantially reduced lead concentrations. At the community scale, we examined how the lack of representation based on household demographics and well construction characteristics impacted the knowledge of lead and blood lead level (BLL) occurrence. When simulating representative demographics of the well populations, we observed that the 90th percentile lead level could differ by up to 6 μg l−1, resulting in communities being above the USEPA action level. This translated to a 1.0–1.3 μg dl−1 difference in predicted geometric mean BLL among infants consuming reconstituted formula. Further, inclusion of less common well construction types also increased lead in water occurrence. Overall, under- and overestimations of lead concentrations associated with differences in sampling techniques and sample representation can misinform conclusions about risks of elevated BLLs associated with drinking water from private wells which may hinder investigations of waterborne lead exposure.

The contribution of secondhand tobacco smoke to blood lead levels in US children and adolescents: a cross-sectional analysis of NHANES 2015–2018

BackgroundLead is a major developmental neurotoxicant in children, and tobacco smoke has been suggested as a source of lead exposure in vulnerable populations. This study evaluates the contribution of secondhand tobacco smoke (SHS) to blood lead levels (BLLs) in children and adolescents.MethodsWe analyze data from 2,815 participants aged 6–19 years who participated in the National Health and Nutrition Examination Survey (2015–2018) to investigate the association between serum cotinine levels and BLLs. A multivariate linear regression was conducted to estimate geometric means (GMs) and the ratios of GMs after adjusting for all covariates.ResultsThe geometric means of BLLs in study participants aged 6 − 19 years were 0.46 µg/dl (95% CI 0.44, 0.49). After adjusting for relevant participant characteristics, the geometric means of BLLs were 18% (BLL 0.48 µg/dl, 95% CI 0.45, 0.51) and 29% (BLL 0.52 µg/dl, 95% CI 0.46, 0.59) higher in participants who had intermediate serum cotinine levels (0.03 − 3 ng/mL) and those who had high serum cotinine levels (> 3 ng/mL) respectively, compared to participants who had low serum cotinine levels (BLL 0.41 µg/dl, 95% CI 0.38, 0.43).ConclusionsSHS exposure may be a source of BLLs in US children and adolescents. Efforts to reduce lead exposure in children and adolescents should include strategies to reduce SHS exposure.

Blood lead levels of children exposed to e-waste: a systematic review and meta-analysis.

Blood lead levels (BLLs) have been decreasing worldwide for decades. However, systematic reviews and quantitative syntheses of BLLs in electronic waste (e-waste)-exposed children are lacking. To summarize temporal trend of BLLs among children in e-waste-recycling areas. Fifty-one studies met the inclusion criteria and included participants from six countries. Meta-analysis was performed using the random-effects model. Results showed that among e-waste-exposed children, the total geometric mean (GM) BLL was 7.54 μg/dL (95% CI: 6.77, 8.31). Children's BLLs displayed a decreasing temporal trend, from 11.77 μg/dL in phase I (2004-2006) to 4.63 μg/dL in phase V (2016-2018). Almost 95% of eligible studies found that children exposed to e-waste had significantly higher BLLs than reference groups. The difference of children's BLLs between the exposure group and the reference group was from 6.60 μg/dL (95% CI: 6.14, 7.05) in 2004 to 1.99 μg/dL (95% CI: 1.61, 2.36) in 2018. For subgroup analyses, except for Dhaka and Montevideo, the BLLs of children from Guiyu in the same survey year were higher than those of children from other regions. Our findings indicate that the gap between BLLs of children exposed to e-waste and those of reference group children is closing, and we appeal that the critical value for blood lead poisoning in children should be lowered in key e-waste-dismantling areas of developing countries, such as Guiyu.

A survey study of factors influencing elevated blood lead levels in donors from Qingdao, China.

That lead is harmful to multiple systems of the human body has been known since antiquity and numerous recent studies have shown that blood transfusion may be an important source of exposure to lead in blood recipients. In this study factors influencing elevated lead levels in blood samples from donors in Qingdao, a city in northern China were investigated to provide screening procedures for blood donors and safer blood transfusions for blood recipients. In 2021, subjects from 15 blood donation sites in Qingdao were selected by stratified random sampling. Blood lead levels (BLL) were analyzed by graphite furnace atomic absorption spectrometry. Multiple linear regression and logistic regression models were used to analyze factors influencing BLL. Of 2,142 blood donors, 1,434 were male and 708 were female, with an average age of 34.8 years. The geometric mean of BLL was 26.03 μg/L (95% confidence interval: 25.52-26.56), and donors in the high blood lead group (≥35 μg/L) accounted for 25.6% of the study population. Multiple linear regression results showed BLL was associated with gender, age, place of residence, duration of residence, and smoking status. Multivariate logistic regression analysis showed that male, increasing age, living in Jimo, duration of residence ≥30 years, and smoking were risk factors for high BLL, with odds ratios (95% confidence intervals) being 2.10 (1.61-2.73), 1.03 (1.01-1.04), 3.89 (1.09-13.86), 1.64 (1.22-2.20), and 1.76 (1.40-2.22), respectively. Male, advanced age, living in Jimo, smoking, and duration of residence ≥30 years were associated with higher BLL. Infusion of blood with elevated lead concentration can be reduced by screening out donors presenting one or more of the above risk factors.

Lead Exposure in Infancy and Subsequent Growth in Beninese Children.

Studies suggest that elevated postnatal blood lead levels (BLLs) are negatively associated with child growth. This study aimed to investigate the associations of childhood BLLs at age one year and growth outcomes at age six years (n = 661) in a cohort of children in Allada, Benin. The growth outcomes studied are weight-for-age Z-score (WAZ), height-for-age Z-score (HAZ), BMI-for-age Z-score (BMIZ), weight-for-height Z-score (WHZ), head circumference (HC), growth velocities, underweight, stunting, and wasting. Multivariable regression models examined the associations between BLLs and growth outcomes, with adjustment for potential confounders. The geometric mean BLLs was 59.3 μg/L and 82% of children had BLLs >35 μg/L at the age of 12.8 months. After adjusting for confounding factors, no overall association was found between BLL quartiles and HAZ, WAZ, BMIZ, WHZ, growth velocities, wasting, and underweight. However, boys in the highest quartile had a 1.02 cm lower HC (95% CI: [−1.81, −0.24]) as compared to the lowest quartile. Furthermore, an increased odds of being stunted was observed in children in the highest quartile of exposure compared to the first (OR: 2.43; 95% CI: [1.11–5.33]) which remained statistically significant only among girls in sex-specific strata. Blood lead was found to be associated with an increased risk of childhood stunting and a lower head circumference in a resource-limited setting.

Prevalence of elevated blood lead levels and risk factors among children living in Patna, Bihar, India 2020.

Childhood lead exposure remains a key health concern for officials worldwide, contributing some 600,000 new cases of intellectually disabled children annually. Most children affected by high exposure to lead live in low- and middle-income countries. The leaded gasoline phase out in India was completed in 2000. Yet, in 2020, an estimated 275 million children aged 0 to 9 years had blood lead levels (BLLs) ≥ 5 μg/dL known to adversely affect intelligence and behavior. Lead sources reported in India include spices, cookware, paint, traditional medicines and cosmetics, and lead-acid battery recycling and repair. However, their relative contribution has not been characterized. More than 200 lead pollution sites related to battery recycling and repair activities were identified in Bihar and Jharkhand, India. Ninety percent of the recycling sites had soil lead concentrations exceeding the US Environmental Protection Agency's standards. We compared blood and environmental lead levels in two groups of children in Patna, Bihar. Households in proximity to battery recycling operations (Proximal n = 67) versus households distal to these operations (Distal n = 68). The average age of children was 40 months; 46% were female. Overall, the geometric mean (GM) BLL was 11.6 μg/dL. GM BLLs of children in Proximal and Distal households were not significantly different (10.2 μg/dL vs. 13.1 μg/dL respectively; p≤0.07). About 87% children, 56 Proximal and 62 Distal had BLLs ≥5 μg/dl. Lead concentrations in environmental samples were significantly higher in Proximal households (soil mean 9.8 vs. 1.6 μg/ft2; dust mean 52.9 vs. 29.9 μg/ft2 p<0.001; Proximal vs. Distal respectively) whereas concentrations in all spices were higher in Distal households (mean 46.8 vs 134.5 ppm p<0.001; Proximal vs. Distal respectively), and turmeric (mean 59.4 vs. 216.9 ppm Proximal vs. Distal respectively). In multivariate analyses for all children lead in spices and turmeric and number of rooms in the house were significant while for the Proximal group only lead in spices remained in the model. The predictive value of these models was poor. For the Distal group, a model with lead concentration in spices, turmeric and soil and number of rooms in the house was a much better fit. Of the 34 water samples collected, 7 were above the Indian standard of 10 ppb for lead in drinking water (2 in the Proximal area, 5 in the Distal area). Children in Patna, Bihar, India are exposed to multiple sources of lead, with lead levels in house dust and loose, locally sourced spices the most likely to increase blood lead levels. A holistic approach to blood lead testing and source identification and remediation are necessary to prevent lead exposure.

Blood lead levels in 2018/2019 compared to 1987/1988 in the German population-based KORA study

IntroductionLead exposure remains of continuing concern due to its known and suspected impacts on human health and has been designated as a priority substance for investigation in human biomonitoring studies by the EU. The aims of this study were to measure blood lead levels (BLL) in a population based cohort of middle-aged individuals without major current exposures to lead, and to compare these to historical blood lead levels obtained thirty years earlier. MethodsThe population-based KORA study from 1984 to 2001 included inhabitants of the Augsburg Region, Germany. During 2018 to 2019, a subsample of these participants (KORA-Fit) was invited for interview regarding demographic and lifestyle factors, physical examination and blood withdrawal. Blood samples were stored at −80C prior to measurement of BLL via graphite furnace atomic absorption spectroscopy (GF-AAS). Descriptive and multivariable analyses were performed. ResultsBLLs were measured in 3033 eligible persons aged 54 to 73, establishing a geometric mean (GM) BLL of 24.8 μg/l in 2018/19. Of these, 555 (18%) had BLL above proposed 95th percentile reference values of the German Environment Agency. Only small differences were found in BLL stratified by sociodemographic categories, however regular smokers had higher GM BLL (26.1 μg/l) compared to never smokers (23.7 μg/l), and an increasing BLL with increased wine consumption was noted. For 556 individuals, BLLs (GM: 54.0 μg/l) reduced by 35% in men and 50% in women compared to levels in 1987/88 with only 1.4% of individuals having an unchanged or increased BLL. DiscussionKORA-Fit provided contemporary normative data for BLL in a Western European population without major current sources of lead exposure. Mean BLLs have fallen since the 1980s using historical BLL data which is likely linked to the ban of leaded gasoline. Nevertheless, BLLs in this population remain elevated at levels associated with morbidity and mortality.

Environmental exposure to lead and oxidative stress biomarkers among healthy children in La Plata, Argentina.

Environmental exposure to lead is still a major public health problem, especially in children. Oxidative stress may be a primary mechanism associated with toxicity. The objective of this study was to measure blood lead levels (BLLs) in children aged 1 to 6 years exposed to lead in La Plata and suburban areas and their relation to oxidative stress biomarkers. Cross-sectional, analytical study. Clinically healthy children aged 1 to 6 years were analyzed. BLLs, antioxidant enzyme activity, and extent of lipid peroxidation were measured. The statistical software package R, version 3.5.1, was used. A total of 131 children participated; their median age was 2.33 years. The geometric mean of BLLs was 1.90 μg/dL; 32% showed a measurable BLL and 3%, BLLs ≥ 5 μg/dL (international reference). The comparison of oxidative stress biomarkers based on BLLs showed a significant difference in median thiobarbituric acid reactive substances (TBARS): 12.0 versus 10.0 nmol MDA/mL of plasma; p = 0.02. In addition, the correlation between BLLs and TBARS was positive (r = 0.24; p = 0.012). Most children had a BLL below the limit recommended by international agencies; although such BLLs do not affect antioxidant enzyme activity, they can induce lipid peroxidation. These results demonstrate the usefulness of this biomarker as an early diagnosis tool to assess subtoxic lead effects.

Abstract P104: High Lead Levels Associated With Elevated Blood Pressure In Haiti: A Warning Sign

Introduction: Cardiovascular disease is the leading cause of death in Haiti and many low-middle income countries. Environmental lead exposure is associated with higher blood pressure (BP) and cardiovascular disease mortality in high income countries but has not been systematically evaluated in lower income countries where 6.5 billion people reside. Hypothesis: We hypothesized higher lead levels would be associated with higher BP in Haiti. Methods: Blood lead levels (BLLs) were measured among 2,257 participants ≥18 years enrolled in a population-based longitudinal cohort study in Port-au-Prince (Haiti Cardiovascular Disease Cohort Study). BLL screening was conducted using LeadCare II (detection limit ≥3.3 μg/dL). BLLs below detection were imputed. Associations between BLLs (quartiles) and systolic BP (SBP) and diastolic BP (DBP) were assessed, adjusting for age, sex, obesity, smoking, physical activity, and income. BLLs were also categorized as ≥5 versus &lt;5 μg/dL. Results: The median age was 40 years; 62.6% were female. The geometric mean BLL was 4.60 μg/dL, 67.3% had detectable BLLs &gt;3.3 μg/dL, and 40.9% had elevated BLLs ≥5 μg/dL. BLLs in quartile four (≥6.5 μg/dL) in both unadjusted and adjusted analyses were associated with higher SBP (adjusted 3.02 mmHg; 95%CI 0.80, 5.25) and DBP (adjusted 2.19 mmHg; 95%CI 0.70, 3.67). BLL ≥5 μg/dL were associated with a higher SBP (2.21 mmHg; 95%CI 0.15, 4.26) and DBP (1.50 mmHg; 95%CI 0.20, 2.81) in unadjusted analysis. After adjustment there was no difference in SBP (1.41; 95%CI -0.25, 3.09) and 1.15 mmHg (95%CI 0.01, 2.30) higher DBP. Conclusions: Widespread environmental lead exposure is evident in urban Haiti, with higher BLLs associated with higher SBP and DBP. Lead is a modifiable pollutant in low-income countries that warrants urgent public health remediation.

Trend in blood lead levels in Taiwanese adults 2005-2017.

This study examined the trend of blood lead levels (BLLs) in Taiwanese adults and analyzed the variations in the BLL between Linkou (northern) and Kaohsiung (southern) hospital branches. Between 2005 and 2017, 3,804 adult participants received blood lead tests at the Linkou (n = 2,674) and Kaohsiung (n = 1,130) branches of Chang Gung Memorial Hospital. The geometric mean of BLL was 2.77 μg/dL. The adult participants from the Kaohsiung branch were not only age older (49.8±14.1 versus 39.4±14.2 years; P<0.001) and male predominant (65.8 versus 41.7%; P<0.001) but also showed a higher BLL (4.45±3.93 versus 2.82±2.42 μg/dL; P<0.001) and lower estimated glomerular filtration rate (87.62±25.94 versus 93.67±23.88; P<0.001) than those from the Linkou branch. Multivariable logistic regression analysis revealed that the Kaohsiung branch [odds ratio (OR): 7.143; 95% confident interval (CI): 5.682-8.929; P<0.001], older age (OR: 1.008; 95% CI: 1.000-1.015; P = 0.043) and reduced estimated glomerular filtration rate (OR: 1.009; 95% CI: 1.004-1.014; P = 0.001) were significant predictors for BLL > 5 μg/dL. Therefore, this study confirmed a continuous decreasing trend in the BLL in Taiwan after banning leaded petrol in 2000.

High Lead Exposure Associated With Higher Blood Pressure in Haiti: a Warning Sign for Low-Income Countries.

Cardiovascular disease is the leading cause of death in lower-income countries including Haiti. Environmental lead exposure is associated with high blood pressure and cardiovascular mortality in high-income countries but has not been systematically measured and evaluated as a potential modifiable cardiovascular risk factor in lower-income countries where 6.5 billion people reside. We hypothesized lead exposure is high in urban Haiti and associated with higher blood pressure levels. Blood lead levels were measured in 2504 participants ≥18 years enrolled in a longitudinal population-based cohort study in Port-au-Prince. Lead screening was conducted using LeadCare II (detection limit ≥3.3 µg/dL). Levels below detection were imputed by dividing the level of detection by √2. Associations between lead (quartiles) and systolic blood pressure and diastolic blood pressure were assessed, adjusting for age, sex, obesity, smoking, alcohol, physical activity, income, and antihypertensive medication use. The median age of participants was 40 years and 60.1% were female. The geometric mean blood lead level was 4.73µg/dL, 71.1% had a detectable lead level and 42.3% had a blood lead level ≥5 µg/dL. After multivariable adjustment, lead levels in quartile four (≥6.5 µg/dL) compared with quartile 1 (<3.4 µg/dL) were associated with 2.42 mm Hg (95% CI, 0.36-4.49) higher systolic blood pressure and 1.96 mm Hg (95% CI, 0.56-3.37) higher diastolic blood pressure. In conclusion, widespread environmental lead exposure is evident in urban Haiti, with higher lead levels associated with higher systolic and diastolic blood pressure. Lead is a current and potentially modifiable pollutant in lower-income countries that warrants urgent public health remediation. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03892265.

Blood Lead Levels in U.S. Children Ages 1-11 years over the 40-year period from 1976 to 2016

BACKGROUND AND AIM: Blood lead levels (BLLs) have generally declined over the past 40 years in the United States (U.S.).We describe the distribution of BLLs in U.S. children age 1-11 years from 1976-2016 and associations with demographic, housing and regional characteristics. METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) II, NHANES III 1988-1991 and 1991-1994, and 1999-2016 NHANES cycles were used to describe the distribution of BLLs in U.S. children age 1-5 years and 6-11 years from 1976-2016. For all children with valid BLLs (n=27,122), geometric mean (GM) BLLs (95% confidence intervals [CI]) and estimated prevalence were calculated overall, stratified by age group (1-5 years; 6-11 years) and selected characteristics. RESULTS:The GM BLL in U.S. children age 1-5 years has declined from 15.2 µg/dL (CI 14.3,16.1) in 1976-1980 to 0.83 µg/dL (CI 0.78,0.88) in 2011-2016, representing a 94.5% decrease over time. A large portion of this decline occurred before 1992 as GM BLLs for 1-5 year olds had decreased to 3.6 µg/dL (CI 3.2,4.0) by 1988-1991. For children age 6-11 years old, GM BLL have declined from 12.7 µg/dL (CI 11.9,13.4) in 1976-1980 to 0.60 µg/dL (CI 0.58,0.63) in 2011-2016, representing a 95.3% decrease. As with the younger age group, much of this decrease occurred before 1992. Despite this substantial decline, disparities exist by income, race/ethnicity, and housing age. CONCLUSIONS:Lead exposure in U.S. children age 1-5 years and 6-11 years has substantially decreased over this forty-year period. Despite this significant achievement, children, particularly those of minority and low-income backgrounds, are still at risk of lead exposure. Risk factors, such as income and housing age, persist throughout regardless of child’s age. NHANES estimates of BLLs have played a key role in monitoring the decline in BLLs in U.S. children and have influenced public health action and national policy around childhood lead exposure. KEYWORDS: Epidemiology, children's environmental health, heavy metals

Lead exposure in infancy and subsequent growth in childhood

BACKGROUND AND AIM: Studies suggest that elevated postnatal blood lead levels (BLL) are negatively associated with child growth. None has examined this association in African populations where the prevalence of malnutrition is high. This study aimed to investigate associations of childhood BLL at age 1 and growth outcomes at age 6 in a cohort of children in Allada, Benin. METHODS: We assessed children for lead in whole blood in 661 children at 12 months and followed them until 6 years (+/- 0.17). Weight, height and head circumference were assessed at a maternity clinic by trained staff at different age points between birth and 6 years. Weight-for-age Z-score (WAZ), height-for-age Z-score (HAZ) and BMI for-age Z-score (BMIZ) were then calculated from modeled individual postnatal growth trajectories from repeated measures of weight and height. Univariate and multivariable regression models examined associations between blood lead levels and growth outcomes with adjustment for potential confounders. RESULTS:The geometric mean of BLL was 59.3 (95% CI: 56.6 - 62.0) and 58.1% of children presented with BLL 50 μg/L. Mean WAZ, HAZ, BMIZ and head circumference (HC) in children at age 6 years were -1.24 (+/- 0.78), -0.31 (+/- 0.83), -1.65 (+/-0.87) and 49.9 cm (+/- 1.8), respectively. Overall, there were few associations between BLL and child growth. In boys only, BLL was associated with HC at age 6 in the crude model, but this association was weaker after adjustment for confounding factors (β = -0.38 cm [95% CI: -0.83, 0.08]). A negative association was observed between BLL at age 1 and HAZ at age 6 in girls, but this association was weaker after adjustment (β = - 0.11[-0.27, 0.03)]). CONCLUSIONS:We found no evidence of a relationship between BLL and physical growth in children living in a resource-poor setting with a high prevalence of undernutrition. KEYWORDS: Heavy metals Outcomes

Blood Lead Levels in U.S. Children Ages 1-11 Years, 1976-2016.

Background:Lead can adversely affect child health across a wide range of exposure levels. We describe the distribution of blood lead levels (BLLs) in U.S. children ages 1–11 y by selected sociodemographic and housing characteristics over a 40-y period.Methods:Data from the National Health and Nutrition Examination Survey (NHANES) II (1976–1980), NHANES III (Phase 1: 1988–1991 and Phase II: 1991–1994), and Continuous NHANES (1999–2016) were used to describe the distribution of BLLs (in micrograms per deciliter; ) in U.S. children ages 1–11 y from 1976 to 2016. For all children with valid BLLs (), geometric mean (GM) BLLs [95% confidence intervals (CI)] and estimated prevalence (95% CI) were calculated overall and by selected characteristics, stratified by age group (1–5 y and 6–11 y).Results:The GM BLL in U.S. children ages 1–5 y declined from (95% CI: 14.3, 16.1) in 1976–1980 to (95% CI: 0.78, 0.88) in 2011–2016, representing a 94.5% decrease over time. For children ages 6–11 y, GM BLL declined from (95% CI: 11.9, 13.4) in 1976–1980 to (95% CI: 0.58, 0.63) in 2011–2016, representing a 95.3% decrease over time. Even so, for the most recent period (2011–2016), estimates indicate that approximately 385,775 children ages 1–11 y had BLLs greater than or equal to the CDC blood lead reference value of . Higher GM BLLs were associated with non-Hispanic Black race/ethnicity, lower family income-to-poverty-ratio, and older housing age.Discussion:Overall, BLLs in U.S. children ages 1–11 y have decreased substantially over the past 40 y. Despite these notable declines in population exposures to lead over time, higher GM BLLs are consistently associated with risk factors such as race/ethnicity, poverty, and housing age that can be used to target blood lead screening efforts. https://doi.org/10.1289/EHP7932

Blood Lead Levels among Blood Donors and High-Risk Occupational Groups in a Mining Area in Ghana: Implications for Blood Transfusion among Vulnerable Populations.

Lead poisoning has been a major global health problem for decades, and blood transfusion has been suspected as a neglected potential source of lead exposure. Children and pregnant women are most vulnerable to the toxic effects of lead and over 40 percent of blood transfused in Ghana is given to children under 5 years. However, there is little data on the levels of lead in donor blood and the main sources of lead exposure in the Ghanaian population. This study compared blood lead levels (BLL) among selected occupations at risk of lead exposure with healthy blood donors in nonexposed occupations in a Ghanaian mining area. We enrolled 40 participants each from the following high-risk occupational groups: small scale miners, painters/sprayers, drivers/fuel station attendants, and auto-mechanics as well as 40 healthy blood donors (made up of teachers, traders, and office workers). One millilitre of blood was collected from each participant for determination of their BLL, haemoglobin concentration, and blood film morphology. A total of 200 participants made up of 186 (93%) males and 14 (7%) females were enrolled. The mean age of participants was 28.6 ± 8.2 years and their geometric mean (GM) BLL was 6.3 GSD 1.4 µg/dL [95% CI: 6.0 – 6.6]. Participants in high risk occupations had significantly higher GM BLL of 6.7 µg/dL [95% CI :6.4−7.0] compared to 5.0 µg/dL [95% CI: 4.4−5.7] for healthy blood donors [p < 0.001]. The prevalence of elevated BLL (≥5 µg/dL) among the entire study participants, high risk occupations and blood donors was 84.5%, 89.4% and 65% respectively. There was significant association between elevated BLLs and working in an at-risk occupational group [aOR = 3.58, p = 0.014]. Haemoglobin concentration was not significantly associated with elevated BLLs. Basophilic stippling was not observed in any of the blood smears. Blood lead levels were high in blood donors and at-risk occupations in the study area and occupation was associated with elevated BLLs. It is important that measures to safeguard the integrity of donor blood go beyond screening for infectious diseases to include screening individuals in high-risk occupations for lead and other heavy metals to ensure that donor blood from such individuals is safe and does not pose potential danger to the health of vulnerable populations such as children and pregnant women.

Prediction of Children’s Blood Lead Levels from Exposure to Lead in Schools’ Drinking Water—A Case Study in Tennessee, USA

Lead (Pb) exposure can delay children’s mental development and cause behavioral disorders and IQ deficits. With children spending a significant portion of their time at schools, it is critical to investigate the lead concentration in schools’ drinking water to prevent children’s exposure. The objectives of this work were to predict students’ geometric mean (GM) blood lead levels (BLLs), the fractions of at-risk students (those with BLLs &gt; 5 μg/dL), and the total number of at-risk students in one Tennessee school district. School drinking water lead concentration data collected in 2019 were input into the Integrated Exposure Uptake Biokinetic (IEUBK) model and the Bowers’ model to predict BLLs for elementary school students and secondary school students, respectively. Sensitivity analyses were conducted for both models. Drinking water concentrations were qualitatively compared with data collected in 2017. Two scenarios were evaluated for each model to provide upper and median estimates. The weighted GM BLL upper and median estimates for elementary school students were 2.35 μg/dL and 0.99 μg/dL, respectively. This equated to an upper estimate of 1300 elementary school students (5.8%) and a median estimate of 140 elementary school students (0.6%) being at risk of elevated BLLs. Similarly, the weighted GM BLL upper and median estimates for secondary school students were 2.99 μg/dL and 1.53 μg/dL, respectively, and equated to an upper estimate of 6900 secondary school students (13.6%) and a median estimate of 300 secondary school students (0.6%) being at risk of elevated BLLs. Drinking water remediation efforts are recommended for schools exhibiting water lead concentrations greater than 15 μg/L. Site-specific soil lead concentration data are recommended since the IEUBK was deemed sensitive to soil lead concentrations. For this reason, soil lead remediation may have a greater impact on lowering children’s BLLs than drinking water lead remediation. Remediation efforts are especially vital at elementary schools to reduce the population’s baseline BLL and thus the BLL projected by Bowers’ model.

Predicting children's blood lead levels from exposure to school drinking water in Addis Ababa, Ethiopia.

Human beings could be exposed to impacts associated with heavy metals such as lead (Pb) through drinking water. The objective of this study was to evaluate quality of water consumed by kindergarten school children in Addis Ababa city, who are highly susceptible to issues related to heavy metals in water. Through conducting chemical analysis, using microwave plasma atomic emission spectrophotometry (MP-AES), the level of lead (Pb) was measured at 38 selected schools in the city. Drinking water samples were taken from three water supply sub-systems: Akaki, Legedadi, and Gefersa. Results revealed the average Pb concentration in the city was 62.37 μg/L which is significantly higher than the World Health Organization (WHO) recommended threshold value of 10 μg/L. The children's blood lead levels and exposure to Pb were also calculated using the integrated exposure uptake bio-kinetic (IEUBK) model as per USEPA guidelines. Estimated geometric mean blood lead levels (BLLs) for each school ranged from 4.4 to 13.2 μg/dL. On average, the model predicted that 20% of children in the city will have blood lead levels above the WHO recommended 10 μg/dL. The study can be considered as an unprecedented piece of work as it addresses critical issues and methods to mitigate problems caused by high concentration of Pb in water supply distribution infrastructure.

Where are we at with lead? Current levels, time trend, and determinants of blood lead in New Zealand children and adults.

A national biomonitoring survey was conducted in 2014-2016, to determine current blood lead levels (BLL) in New Zealand children and adults and identify determinants of BLL. Blood samples were provided by 191 children (age 5-18) and 304 adults (age 20-65) and analysed for BLL using inductively coupled mass spectroscopy. Linear regression on log-transformed BLL was used to assess associations between BLL and demographic and lifestyle factors collected via questionnaire. The geometric mean (GM) BLL was 0.86μg/dl (95%CI 0.80-0.92) for children and 1.31μg/dl (1.23-1.39) for adults, representing a 90% reduction in BLL over the past 36 years. For children, shellfish consumption was associated with 20% higher BLL. Adult BLLs were positively associated with age, beer consumption, spirits consumption, having roof water as the home's water supply, and having worked in glass manufacturing. Determinants of reduced BLL were tofu and canned food consumption. For women, menopause was associated with 34% higher BLL. Although significant reductions in New Zealanders' BLL have been achieved in the past decades, this study identified several additional opportunities to reduce further background exposure to lead. In particular, consideration needs to be given to reducing lead levels in New Zealand roof water supplies.

Blood Lead Levels in U.S. Women of Childbearing Age, 1976-2016.

Background:Lead can adversely affect maternal and child health across a wide range of exposures; developing fetuses and breastfeeding infants may be particularly vulnerable. We describe the distribution of blood lead levels (BLLs) in U.S. women of childbearing age and associations with sociodemographic, reproductive, smoking, and housing characteristics over a 40-y period.Methods:Data from the National Health and Nutrition Examination Survey (NHANES) II, NHANES III Phase I and Phase II, and 1999–2016 continuous NHANES were used to describe the distribution of BLLs (given in micrograms per deciliter; ) in U.S. women 15–49 years of age between 1976 and 2016. For all women with valid BLLs (), geometric mean (GM) BLLs and estimated prevalence of BLLs were calculated overall and by selected demographic characteristics. For NHANES II, estimated prevalence of BLLs and were also calculated.Results:The most recent GM BLLs (2007–2010 and 2011–2016, respectively) were [95% confidence interval (CI): 0.79, 0.84] and (95% CI: 0.59, 0.64). In comparison, GM BLLs in earlier periods (1976–1980, 1988–1991, and 1991–1994) were (95% CI: 9.95, 10.79), (95% CI: 1.75, 1.94), and (95% CI: 1.45, 1.60), respectively. In 2011–2016, 0.7% of women of childbearing age had BLLs , and higher BLLs were associated with older age, other race/ethnicity, birthplace outside the United States, four or more live births, exposure to secondhand tobacco smoke, and ever pregnant or not currently pregnant.Discussion:Lead exposure in U.S. women of childbearing age is generally low and has substantially decreased over this 40-y period. However, based on these estimates, there are still at least 500,000 U.S. women being exposed to lead at levels that may harm developing fetuses or breastfeeding infants. Identifying high-risk women who are or intend to become pregnant remains an important public health issue. https://doi.org/10.1289/EHP5925