Blood Lead Levels and Risk Factors for Lead Exposure in a Pediatric Population in Ho Chi Minh City, Vietnam

How does formal and informal industry contribute to lead exposure? A narrative review from Vietnam, Uruguay, and Malaysia

INTRODUCTION

Lead industries are one of the major sources of environmental pollution and can affect human through different activities, including industrial processes, metal plating, mining, battery recycling, etc. Although different studies have documented the various sources of lead exposure, studies highlighting different types of industries as sources of environmental contamination are limited. Therefore, this narrative review aims to focus mainly on lead industries as significant sources of environmental and human contamination.

CONTENT

Based on the keywords searched in bibliographic databases we found 44 relevant articles that provided information on lead present in soil, water, and blood or all components among participants living near high-risk areas. We presented three case scenarios to highlight how lead industries have affected the health of citizens in Vietnam, Uruguay, and Malaysia.

SUMMARY AND OUTLOOK

Factories conducting mining, e-waste processing, used lead-acid battery recycling, electronic repair, and toxic waste sites were the primary industries for lead exposure. Our study has shown lead exposure due to industrial activities in Vietnam, Uruguay, Malaysia and calls for attention to the gaps in strategic and epidemiologic efforts to understand sources of environmental exposure to lead fully. Developing strategies and guidelines to regulate industrial activities, finding alternatives to reduce lead toxicity and exposure, and empowering the public through various community awareness programs can play a crucial role in controlling exposure to lead.

Blood lead levels mediate the relationship between social adversity and child externalizing behavior

BACKGROUND/AIMS

The association between social adversity and externalizing behavioral problems in children is well-documented. What is much less researched are biological mechanisms that may mediate such relationships. This study examines the hypothesis that low blood lead mediates the relationship between social adversity and child externalizing behavior problems.

METHODS

In this cross-sectional study, participants were 131 children aged 11-12 years (mean = 11.90) from Philadelphia, US. A venous fasting blood sample was taken and analyzed for blood lead levels. A social adversity index was calculated based on 10 total indicators derived from a psychosocial interview of the parent and official neighborhood data, while child behavior outcomes (internalizing and externalizing behavior) were assessed using both parent-report and child self-report.

RESULTS

The mean blood lead level was 2.20 μg/dL. Both relatively higher blood lead levels and higher social adversity scores were associated with higher levels of parent-reported and child self-reported externalizing behaviors. Additionally, blood lead mediated the relationship between social adversity and child-reported externalizing behavior (Indirect effect: B = 0.03, 95% CI: 0.004, 0.09) and partially mediated the relationship between social adversity and parent-reported externalizing behavior (Indirect Effect: B = 0.03, 95% CI: 0.01, 0.07).

CONCLUSION

To our knowledge, this study is the first to suggest that blood lead levels play a mediating role in the relationship between externalizing behavior problems and social adversity. Findings have potentially important implications for public health and environmental regulation as well as understanding biological mechanisms that link social inequality with health outcomes, especially in youth from low-income, urban areas.

Blood lead concentrations among pediatric patients with abdominal pain: a prospective cross-sectional study

Background

Lead exposure is one of the most menacing of environmental exposures, particularly in children. Children are more susceptible to the effects of lead which manifest in many organ systems, including interference with mental and motor development. Lead poisoning can cause colicky abdominal pain. In this study, the authors sought to evaluate the prevalence of elevated blood lead level (BLL) and its contributing factors among pediatric patients presenting with abdominal pain. An epidemic of lead poisoning in adults was previously uncovered, and thus a concern for pediatric lead poisoning was raised.

Methods

Pediatric patients presenting to two pediatric clinics in Tehran with abdominal pain were eligible for enrollment in a descriptive prospective cross-sectional study. A predesigned questionnaire was filled for each patient by their consenting parents. The questionnaire queried demographic information, environmental, social, and other relevant parameters for lead exposure. After completion of the questionnaire, biometrics were obtained, and a blood sample was taken from each patient for measurement of BLL and complete blood count.

Results

A total of 187 patients were enrolled in the study. Of them, almost 20% had BLL ≥ 5 µg/dL. Univariate analysis showed that age (p = 0.002, OR 3.194, CI 95% 1.504–6.783), weight (p = 0.009, OR 2.817, CI 95% 1.266–6.269), height (p = 0.003, OR 3.155, CI 95% 1.443–6.899), and playing with both plastic and cotton toys (p = 0.03, OR 2.796, CI 95% 1.072–7.295) were significant predictors of high BLLs. Maternal level of education correlated with blood lead concentrations (p = 0.048, OR 2.524, CI 95% 1.006–6.331).

Conclusions

A clinically significant number of cases of abdominal pain may have high BLLs. Specific attention should be paid to children presenting with abdominal pain, especially due to the detrimental effects of lead on their mental and motor development.

Spatio-temporal assessment of ambient air quality, their health effects and improvement during COVID-19 lockdown in one of the most polluted cities of India

The present work aims to investigate seasonal variations in air pollution levels in Lucknow and assess the ambient air quality of the city together with highlighting the health impacts of major pollutants like PM10, PM2.5, SO2, NO2, Pb, Ni and aerosols from 2010 to 2019. The maximum and minimum values of PM10, PM2.5, SO2, NO2, Pb and Ni were found to be 270.75 and 122.45 μg/m3, 124.95 and 95.52 μg/m3, 25.60 and 8.05 μg/m3, 75.65 and 23.85 μg/m3, 0.66 and 0.03 μg/m3 and 0.07 and 0.01 ng/m3, respectively. Health impact of particulate matter has also been assessed with AirQ+, and it was estimated that long-term exposure of PM10 was attributed to between 37 and 48% for post-neonatal (age 1-12 months) mortality rate due to all causes, whereas long-term attributable proportions in mortality due to exposure of PM2.5 were to about 19 to 28% from all causes. Further, an attempt has also been made to evaluate the impact of lockdown amid COVID-19 on the ambient air quality of Lucknow. During the lockdown, PM2.5 levels reduced by 65% (at Gomti Nagar), 23% (at central school), 79% (at Lalbagh) and 35% (at Talkatora), due to which, air quality index of Gomti Nagar came down to 43, well below 50 which falls in the healthy range. NO2 levels also came down. However, levels of SO2 did not show significant reduction. Correlating the data between aerosol optical depth and Angstrom exponent by Pearson correlation analysis revealed a significant positive correlation (r = 0.65, P < 0.001).

Risk of Lead Exposure from Transport Stations to Human Health: A Case Study in the Highland Province of Vietnam

Lead (Pb) is a heavy metal that negatively affects human health. Many studies have shown the relationship between lead exposure and various human activities, of which automobile service stations with gasoline emissions are considered the main cause. However, a limited number of studies have specifically considered lead exposure from automobile stations in Vietnam, as well as its impact on human activities and the surrounding natural resources. The objective of this study was to assess the possible risks of lead exposure to the surrounding agricultural and non-agricultural farms of a bus station located in the center of Dalat city, Lamdong province, Vietnam. To address this objective, 45 samples were collected from the soil, irrigated water resources, and vegetable crops of areas both close to and far away from the bus station. These samples were tested using the atomic absorption spectrometry technique. Our findings demonstrated higher lead concentration levels from all three types of samples collected from areas near the bus station. Of which, soil and water samples showed higher than normal exposure values of lead, but these were still under the allowed limits established by the Vietnam standard. Different from the soil and water, vegetable samples surrounding the bus station presented greater lead contamination than the permitted limit. High risk quotient (RQ) indexes were detected to point out that accumulative consumption of leaded vegetables over time could cause lead poisoning and harm human health. This study not only provides significant inferential evidence of the risk of lead exposure to agricultural activities and human health in Vietnam, but also delivers a real-life example for a real-world context.

Childhood lead poisoning in Gaza Strip, the Palestinian Authority

PURPOSE

To assess lead poisoning among a pediatric population in Gaza Strip, the Palestinian Authority.

METHODS

A total of 1705 questionnaires and blood samples were collected from children aged 2-6 years, by the finger stick capillary procedure, for the assessment of blood lead level (BLL), using the LeadCare kits. The samples were collected from children living close to lead processing units (hotspots) and far 100-500 m away (general population). Management of elevated BLL was achieved by gavage of chelating agent d-penicillamine at a dose of 30 mg kg^-1 body weight/day for two weeks for children having BLL above 20 μg/dl. Data were statistically analyzed using SPSS computer program version 22.

RESULTS

Distribution of children in Gaza Strip by sampling process illustrated those 326 children (19.1%) living in lead processing units (hot spots) and 1379 children (80.9%) from location far away 100-500 m from host spot (general population). The mean BLL was 10.4 μg/dl. A total of 440 children (25.8%) were found to be having BLL ≥ 10 μg/dl while 1265 children (74.2%) have BLL < 10 μg/dl. BLL < 10 μg/dl was taken as a cut point due to CDC standards. The prevalence of BLL in hotspot areas in children who were exposed to lead and have BLL ≥ 10 μg/dl was 95.7% while in general population it was 9.3%. The difference between the study population was statistically significant (p < 0.01). Statistical significant differences between the study populations were found among several independent variables of risk factors such as household location and exposure sources, and occupational exposure. Gavage of d-penicillamine significantly reduced BLL to the acceptable level (BLL < 10 μg/dl).

CONCLUSIONS

Childhood lead poisoning accounts for a substantial burden in Gaza Strip. Hotspots of lead-related industries are the high risk areas that contributing to high BLLs in children. d-Penicillamine was effective in the treatment of lead poisoning among children. Health education and treatment campaigns should be designed to minimize or prevent childhood lead poisoning in Gaza Strip.

Prevalence of Blood Lead among Children Living in Battery Recycling Communities in Greater Jakarta, Indonesia

This study aimed to assess the prevalence of blood lead levels (BLLs) among children 1 to 5 years old who reside near and distant to informally used lead-acid battery (ULAB) recycling locations and examine risk factors for elevated BLLs. A cross-sectional study was conducted in three greater Jakarta neighborhoods where informal ULAB recycling occurs. Venous BLLs among 279 children were analyzed using portable blood lead testing machines. Demographic, child activities, and sources of lead exposure inside and outside homes were assessed. Multivariate analysis was performed to evaluate factors associated with the prevalence of BLLs. Forty-seven percent of children had BLLs ≥ 5 µg/dL and 9% had BLLs ≥ 10 µg/dL. No differences in geometric mean BLLs were observed between children who lived near and distant to ULAB locations. Older child age groups [Prevalence Ratio (PR) 2.14, 95% Confidence Interval (CI) 1.16, 4.18) and low household income (PR 1.58, 95% CI 1.03, 2.40) were associated with BLLs 5-9 µg/dL. Low educational attainment of the child's father (PR 3.17, 95% CI 1.23, 8.16) and frequent outdoor child activity (PR 4.93, 95% CI 1.09, 22.21) were predictors of BLLs ≥ 10 µg/dL. This study shows the association between lead exposure among children and environmental sources. Public health officials can consider expanded surveillance, health care provider education, and development of strategies to reduce lead exposure.

Effects of ALAD genotype on the relationship between lead exposure and anthropometry in a Cohort of Mexican children

OBJECTIVES

Lead exposure is associated with children's growth, but this relationship may depend on the presence of susceptibility factors, including genetic variation. Blood lead levels (BLL) differ by ALAD (aminolevulinic acid dehydratase) genotype. We investigated the association between BLL and growth in Mexican first-graders with different ALAD genotypes.

METHODS

Children between the ages of 6-8 years (n = 602) attending first grade in schools within the vicinity of a metal foundry in Torreón, Mexico were enrolled into a randomized controlled trial (RCT) testing the efficacy of iron and/or zinc supplementation on blood lead levels (BLL) and cognition. BLL and anthropometry were assessed at baseline (height, height-for-age z-score (HAZ), knee height, head circumference), after 6 (head circumference) and 12 months (height, HAZ, knee height). Children with ALAD_1-1 and ALAD_1-2/2-2 were compared. The study sample included 538 and 470 participants who had complete data at baseline and follow-up, respectively. Separate multivariable linear regression models adjusted for covariates were used to test the association between BLL at baseline and each anthropometric measure. Covariates included age, sex, hemoglobin, crowding, and maternal education. BLL x ALAD genotype interaction term was tested.

RESULTS

Median BLL (10.1 μg/dL) did not differ by ALAD genotype. After covariate adjustment, baseline BLL was inversely associated with baseline height, HAZ, and knee height. The association (β [95% CI]) between BLL and baseline height (-0.38[-0.68, -0.09]), HAZ (-0.07[-0.12, -0.02]) and knee height (-0.14[-0.25, -0.02]), was somewhat stronger in children with ALAD_1-2/2-2 than ALAD_1-1 (-0.09[-0.16, -0.02], -0.02[-0.03, -0.004] and -0.04[-0.06, -0.01], respectively). No associations between BLL and growth at 6 or 12 months were detected irrespective of ALAD genotype.

CONCLUSIONS

BLL was adversely associated with anthropometric measures among Mexican children. ALAD genotype may be a susceptibility factor for the effects of lead on child growth.

Children's Environmental Health in South and Southeast Asia: Networking for Better Child Health Outcomes

Children are particularly vulnerable to environmental hazards because they receive higher doses of pollutants in any given environment and often do not have equitable access to social protection mechanisms such as environmental and health care services. The World Health Organization established a global network of collaborating centres that address children’s environmental health (CEH). The network developed a focus on low- and middle-income countries (LMICs) and is broadening its reach by conducting regional workshops for CEH.

Lead Exposure in Low and Middle-Income Countries: Perspectives and Lessons on Patterns, Injustices, Economics, and Politics

Lead exposure is a legacy issue that continues to affect vulnerable population groups globally, but particularly in low and middle-income countries (LMICS). We take a multi-disciplinary approach to examine the patterns of lead exposure in these countries, discuss the underlying injustices and socio-political causes, and the economic costs that are associated with exposure. We conclude with some lessons we drew from our discussion of lead across the disciplines and advocate for a number of approaches to solving this ongoing issue. These include (i) biomonitoring that could be integrated into existing health surveys or public health programs targeting young children; (ii) greater civic engagement to push for solutions; and, (iii) environmental control policies that represent a continuum of local, context-specific to broad, national-level, and even global approaches.

Yucca schidigera extract modulates the lead-induced oxidative damage, nephropathy and altered inflammatory response and glucose homeostasis in Japanese quails

The present study was conducted to explore the toxic effects of lead (Pb) on the physiological responses of Japanese quails and to investigate the potential modulatory role of Yucca schidigera extract (YSE) against these effects. 360 mature Japanese quails (at 2 months of age) were used and the experiment was lasted for 8 weeks. The birds were divided into six equal groups as follow: control (basal diet, BD), BD+Pb (100 mg/kg diet), BD+YSE (100 mg/kg diet), BD+YSE (200 mg/kg diet), BD+Pb (100 mg/kg diet) +YSE (100 mg/kg diet) and BD+ Pb (100 mg/kg diet) + YSE (200 mg/kg diet). Pb induced a significant reduction in superoxide dismutase (SOD) and catalase (CAT) activities and reduced glutathione (GSH) level. While, increased protein carbonyl (PC) and malondialdehyde (MDA) content in tissues of exposed birds. Pb increased level of 8-hydroxy-2-deoxyguanosine (8-OHdG) and lactate dehydrogenase (LDH) activity in serum. YSE significantly reduced the Pb -induced oxidative stress in co-treated groups especially at 200 mg/kg diet. YSE could modulate the Pb -induced decreased urea, creatinine and beta-2 microglobulin (B2M) levels. YSE200 was found to be better than the YSE100 in decreasing levels of inflammatory markers including tumor necrosis factor (TNF-α), nitric oxide (NO), transforming growth factor-β1 (TGF-β1) and vascular endothelial growth factor (VEGF). Furthermore, YSE significantly regulates glucose homeostasis in co-exposed quails. Pb residues were found to be significantly higher in kidney and pancreas tissues of Pb group compared to other groups. YES decreased the expression of metallothionein-1 in the renal and pancreatic tissues, while elevated insulin expression in the pancreatic cells by immunostaining in co-exposed groups. In conclusion, the present results conclusively demonstrate the potential modulatory effect of YSE against the Pb-induced toxic effects in different organs of Japanese quails.

Lead exposure is associated with risk of impaired coagulation in preschool children from an e-waste recycling area

Environmental lead exposure leads to various deleterious effects on multiple organs and systems, including the hematopoietic system. To explore the effects of lead exposure on platelet indices in preschool children from an informal, lead-contaminated electronic waste (e-waste) recycling area, we collected venous blood samples from 466 preschool children (331 from an e-waste area (Guiyu) and 135 from a non-e-waste area (Haojiang)). Child blood lead levels (BLLs) were determined by graphite furnace atomic absorption spectrophotometry, while platelet indices were quantified using a Sysmex XT-1800i hematology analyzer. Higher blood lead levels are observed in e-waste lead-exposed preschool children. Significant relationships between high blood lead levels (exceeding current health limits) and elevated platelet count (PLT), plateletcrit (PCT), mean platelet volume (MPV), and platelet large cell ratio (P-LCR) were also uncovered. Furthermore, the median PLT and PCT levels of children from the exposed group both exceeded the respective recommended maximum reference range value, whereas the reference group did not. Location of child residence in Guiyu and BLLs were both risk factors related to platelet indices. These results suggest that high blood lead exposure from e-waste recycling may increase the risk of an amplified coagulation process through the activation of platelets in preschool children.