Lead exposure in Chinese children: Urbanization lowers children's blood lead levels (BLLs).

Lead is a toxic metal that can pose a huge threat to children's health. China has experienced rapid urbanization since the reform in 1978; however, there has been no examination of the potential influence of this urbanization on children's blood lead levels (BLLs). This study is the initial investigation to explore the correlation between urbanization and BLLs in Chinese children. Five windows of time are considered: pre-2000, 2001-2005, 2006-2010, 2011-2015 and 2016-2021. The results show that urbanization affected lead distribution in urban soil and agricultural soil during the above periods, especially in northern China. The higher non-carcinogenic risk of lead for children is consistent with the lead pollution in soil (3 < Igeo ≤ 4). Urban children's BLLs are slightly higher than those of rural children in 2001-2010, but rural children's BLLs in 2011-2021 are higher than those of urban children during China's urbanization. The areas of rural decline and the areas of urban growth increased across all the window periods. However, the BLLs decrease in all rural and urban areas during all window periods, especially in urban areas. Children's BLLs have a significantly negative correlation with urban areas (p < 0.01). Therefore, China's urbanization has a significant effect on the decrease in children's BLLs. The significance of this study is to provide a fresh perspective and innovative strategy for policymaking in order to reduce children's BLLs and prevent lead exposure. This can be achieved by transforming their external living environment from a rural lifestyle to an urban one, while also ensuring access to well education and maintaining a balanced nutrient intake.

Outbreak of lead poisoning from a civilian indoor firing range in the UK.

INTRODUCTION: Lead exposure from discharged lead dust is a recognised risk at firing ranges. We report a lead poisoning outbreak among staff and their close contacts at a UK civilian indoor 24 m firing range. METHODS: A retrospective review was undertaken of data collected on all patients at risk of lead poisoning identified either by direct referral to the Clinical Toxicology clinicians at the West Midlands Poisons Unit, or via the Trace Elements Supra-Regional Assay Service Laboratory at Sandwell hospital. RESULTS: Eighty-seven patients were identified as having possible lead exposure, either at the firing range or via close contacts. Of these, 63 patients aged between 6 months and 78 years attended for blood lead concentration (BLC) testing. The highest BLC at presentation was 11.7 µmol/L (242 µg/dL). Only nine patients reported any symptoms at presentation. Fifteen patients received lead chelation therapy with oral dimercaptosuccinic acid (or succimer) 30 mg/kg/day or intravenous sodium calcium edetate (EDTA) 75 mg/kg/day, dependent on stock availability. DISCUSSION: This report highlights the need for vigilance of lead poisoning as an occupational hazard in the UK, including at recreational facilities such as indoor firing ranges. It emphasises the importance of regulation of lead exposure in the workplace, particularly given the vague symptoms of lead poisoning, and proposes re-appraisal of UK legislation. This report also highlights potential issues surrounding stock availability of rarely used antidotes for uncommon presentations in the event of an outbreak of poisoning.

Who tests for lead and why? A 10-year analysis of blood lead screening, follow-up and CNS outcomes in a statewide US healthcare system.

OBJECTIVES: This study aims to determine (1) which providers in US healthcare systems order lead tests, why and at what frequency and (2) whether current patient population lead levels are predictive of clinical outcomes. METHODS: Retrospective medical record study of all blood lead tests in the Medical University of South Carolina healthcare system 2012-2016 and consequent evidence of central nervous system (CNS)-related disease across a potential 10-year window (2012-2022). RESULTS: Across 4 years, 9726 lead tests resulted for 7181 patients (49.0% female; 0-94 years), representing 0.2% of the hospital population. Most tests were for young (76.6%≤age 3) and non-Hispanic black (47.2%) and Hispanic (26.7%) patients. A wide variety of providers ordered tests; however, most were ordered by paediatrics, psychiatry, internal medicine and neurology. Lead levels ranged from ≤2.0 µg/dL (80.8%) to ≥10 µg/dL (0.8%; max 36 µg/dL). 201 children (3.1%) had initial lead levels over the reference value for case management at the time (5.0 µg/dL). Many high level children did not receive follow-up testing in the system (36.3%) and those that did often failed to see levels fall below 5.0 µg/dL (80.1%). Non-Hispanic black and Hispanic patients were more likely to see lead levels stay high or go up over time. Over follow-up, children with high lead levels were more likely to receive new attention-deficit/hyperactivity disorder and conduct disorder diagnoses and new psychiatric medications. No significant associations were found between lead test results and new CNS diagnoses or medications among adults. CONCLUSIONS: Hospital lead testing covers a small portion of patients but includes a wide range of ages, presentations and provider specialities. Lack of lead decline among many paediatric patients suggests there is room to improve provider guidance around when to test and follow-up.

Clinical case analysis of 32 children aged 0-6 years with lead poisoning in Nanning, China.

Lead is one of the heavy metals that is toxic and widely distributed in the environment, and children are more sensitive to the toxic effects of lead because the blood-brain barrier and immune system are not yet well developed. The objective of the study was to investigate the clinical characteristics of lead poisoning in children aged 0∼6 years in a hospital in Guangxi, and to provide scientific basis for the prevention and treatment of lead poisoning. We collected and analyzed the clinical data of 32 children with lead poisoning admitted to a hospital in Guangxi from 2010 to 2018. The results showed that most of the 32 cases presented with hyperactivity, irritability, poor appetite, abdominal pain, diarrhea, or constipation. The hemoglobin (HGB), mean corpusular volume (MCV), mean corpuscular hemoglobin (MCH), and hematocrit (HCT) of the lead-poisoned children were all decreased to different degrees and were below normal acceptable levels. Urinary ß2-microglobulin was increased. Blood lead levels (BLL) decreased significantly after intravenous injection of the lead chelator, calcium disodium edetate (CaNa2-EDTA). In addition, HGB returned to normal levels, while MCV, MCH, and HCT increased but remained below normal levels. Urinary ß2-microglobulin was reduced to normal levels. Therefore, in this cohort of children, the high-risk factors for lead poisoning are mainly Chinese medicines, such as baby powder. In conclusion, lead poisoning caused neurological damage and behavioral changes in children and decreased erythrocyte parameters, leading to digestive symptoms and renal impairment, which can be attenuated by CaNa2-EDTA treatment.

Secular trends in blood lead concentrations of school-age children in Montevideo, Uruguay from 2009 to 2019.

Lead exposure continues to be a public health problem globally, yet very few countries perform systematic biomonitoring or surveillance of children's blood lead levels (BLLs). Secular trends in children's BLLs have not been well characterized outside North America and Europe. In 2009-19, we conducted a series of non-representative cross-sectional surveys in Montevideo, Uruguay, enrolling children living in areas of the city with known or suspected lead contamination. Lead was measured with atomic absorption spectrometry on fasting venous blood samples. Of the 856 children representing independent (non-sibling) observations, 759 had BLL measures. Other missing data were imputed. Using linear and logistic regression models, we estimated the covariate-adjusted year to year difference in mean BLL and the likelihood of having BLL ≥5 and BLL ≥3.5 µg/dL. At the start of the study, mean ± SD BLL was 4.8 ± 2.6 µg/dL, and at the end 1.4 ± 1.4 µg/dL. The prevalence of BLL ≥5 and BLL ≥3.5 µg/dL also differed markedly between 2009 and 2019 (30.8% vs. 2.7% and 53.8% vs. 5.8%). Similarly, where 80.8% of children had BLL ≥2 µg/dL in 2011, in 2019 that number was 19.3%. The estimated year to year difference in BLL was ∼0.3 µg/dL. Despite this progress, pediatric lead exposure remains a problem in Montevideo. In years 2015-19, between 19 and 48% of school children had BLL ≥2 µg/dL, a level at which adverse neurobehavioral outcomes continue to be reported in the literature. Continued prevention and risk-reduction efforts are needed in Montevideo, including systematic surveillance of BLLs in all children.

Gastrointestinal Manifestations of Lead Poisoning: A Brief Report.

Gastrointestinal (GI) manifestations of lead poisoning include abdominal pain, constipation, and diarrhea. Depending on the severity of a symptom, surgical consultation is required. The present study aimed to make a comparison between the mean blood lead levels of patients hospitalized for lead toxicity and the various Gl symptoms. A retrospective cross-sectional study was performed in 2020 at Khorshid Hospital, the main regional referral center for poisoned patients (Isfahan, Iran). A total of 82 patients aged ≥18 years who were hospitalized for lead poisoning during 2017-2018 were included in the study. Patients' information was extracted from hospital medical records, including demographic information, clinical manifestations, blood lead levels, and treatment outcome. The mean age of the patients was 48.18±11.9 years, 91.5% were men, and 62.2% suffered from multiple GI symptoms, with abdominal pain being predominant (31.7%). Blood lead levels in patients with multiple GI symptoms were higher than those with only one symptom (P=0.01). Surgical consultation was required in 14.6% of the patients. Multiple GI symptoms were the main predictive factor for blood lead levels above 70 mg/dL (P=0.03, Odds ratio=3.06, 95% CI=1.09-8.61). Given the prevalence of abdominal pain and its association with elevated blood lead levels, differential diagnosis of abdominal pain should include lead toxicity.

Making the case for lead safe housing: Downstream effects of lead exposure on outcomes for children and youth.

Lead based paint is a predominate source of lead exposure in children, which has a documented negative effect on their health and development. Despite public health efforts, the housing stock in disinvested neighborhoods in many cities continues to present significant risk of childhood lead exposure. In this article, we describe how a multi-agency integrated data system was used to document the impact of lead exposure on indicators of child and youth development as recorded in educational and human service systems. By tracking administrative data for two cohorts of Cleveland, Ohio children from birth to early adulthood and using rigorous matching methods to reduce confounders when comparing those with and without elevated blood lead levels, we document negative effects on developmental, behavioral and socio-economic outcomes due to early childhood lead exposure. The magnitude of disparities between individuals who had elevated blood lead levels (≥5 µg/dL) in early childhood, compared to their matched counterparts, is in the ranges of 20-40%. The analysis is framed by clarifying the context, assumptions and limitations associated with the use of administrative data. This type of information has been useful in illuminating the burden of lead exposure for children, families and youth serving agencies and engaging public officials, landlords and residents in initiatives to bring housing up to lead safe standards.

Neurotoxicity and Outcomes from Developmental Lead Exposure: Persistent or Permanent?

BACKGROUND: Childhood lead poisoning remains an important public health issue in the United States, as well as elsewhere in the world. Although primary prevention is a major goal and it is critically important to keep children from getting poisoned, it is also important to explore ways to reduce the neurotoxic effects of lead in those children already poisoned. Whether lead-induced neurotoxicity and its related adverse outcomes are viewed as "permanent" or "persistent" may influence the way in which potential remediation efforts are considered for improving outcomes from childhood lead poisoning. OBJECTIVES: The objective of this commentary was to discuss the ideas of permanence and persistence in relation to the direct neurotoxic effects of lead on the brain and the resulting adverse outcomes from these effects. Recent new insights regarding potential mitigation of lead-induced neurotoxic effects on brain and behavior are considered along with clinical information on neurorehabilitation to suggest potential strategies for improving cognitive/behavioral outcomes in lead-poisoned children. DISCUSSION: The distinction between permanent and persistent in regard to lead-induced neurotoxicity and its resulting outcomes may have broad implications for public health policies in response to the problem of childhood lead exposure. The term permanent implies that the damage is irreversible with little chance of improvement. However, there is evidence that at least some of the adverse cognitive/behavioral outcomes from lead exposure are persistent rather than permanent and potentially amenable, under the appropriate circumstances, to some level of mitigation. This author recommends that clinical, interventional research efforts be devoted to exploring optimal neurorehabilitative and enrichment conditions to stimulate plasticity and enhance functioning to determine the extent to which promising results from preclinical studies of lead-induced brain damage and the mitigation of these effects can be successfully translated to humans. https://doi.org/10.1289/EHP12371.

Redlining and Lead Poisoning: Causes and Consequences.

In 1934, the Federal Housing Authority precluded mortgage loans to residents of neighborhoods with non-White families or where housing was deteriorated; these were declared "hazardous" and labeled red on maps. In 1962 three redlined north Brooklyn neighborhoods had 41 children, all Black and Puerto Rican, with lead levels >60ug/dL. A review of public polices in the U.S. from 1898 to the present revealed that lead poisoning followed an income gradient with multiple disproportionate effects on non-White children in redlined neighborhoods. The poisonings diminished when federal and local regulations prevented lead exposure. While redlining had profound influences on both likelihood and severity of lead poisoning and its consequences, it was a mediator of effects. The principal causes were federal policies failing to prevent environmental contamination and local governments failing to prevent exposure.

Analysis of blood lead level and its clinical significance among occupational exposed painters in chennai based population: A cross sectional study.

INTRODUCTION AND AIM: Lead is a ubiquitous element found in the earth crust. There is no known physiologic role of lead in human body and hence any amount of lead present in human tissue considered as a contamination. Several studies on lead toxicity show that, occupational exposure remains the main source for lead toxicity and is emerging as important public health problem. Burden and severity of occupational exposure of lead and its clinical significance are gaining more interest in the field of toxicology. Only limited studies are available and there is scarcity of epidemiology data to assess the blood lead levels of workers and the contribution of common workplace practices to lead exposure in India especially from our region. So, the current study is designed to assess the blood lead levels (BLL) and its clinical significance among high risk workers especially painters working in the construction and public private sector in Chennai based population. MATERIALS AND METHODS: This cross-sectional case control study included 122 painters and 122 healthy individuals. A detailed questionnaire about demographic details, personal habits, work related safety precautions, presenting symptoms of lead toxicity were given to painter followed by detailed medical examination and blood investigations including blood lead levels were collected and statistically analyzed. The t-test were used to compare mean blood lead levels and to investigate the associations between specific job type, use of self-protection device,sex, service years and occurrence of non-specific symptoms with BLLs. RESULTS: The mean BLL of the painters were less than the recommended threshold level. Among painters 13.1% were categorized under BLL > 10 µg/dL. The higher BLL among the painters were directly proportional to year of experience and poor usage of personal protective materials. The levels of Hb, HCT and eosinophil were much correlated with lead toxicity. A marginal significance were observed in some parameters especially urea and creatinine when compared with control. The Cognitive dysfunction, hypertension and renal dysfunction were also observed among the painters. CONCLUSION: The BLL in painters among our group were minimal compared to biological reference value. Duration of exposure and association of patient's clinical features like cognitive dysfunction, hypertension and renal dysfunction conditions were observed and this should be carefully monitored and study on huge population of painters with longitudinal aspect is recommended to rule out the clinical correlation of lead toxicity.

Hidden hazards and screening policy: Predicting undetected lead exposure in Illinois.

Lead exposure still threatens children's health despite policies aiming to identify lead exposure sources. Some US states require de jure universal screening while others target screening, but little research examines the relative benefits of these approaches. We link lead tests for children born in Illinois between 2010 and 2014 to geocoded birth records and potential exposure sources. We train a random forest regression model that predicts children's blood lead levels (BLLs) to estimate the geographic distribution of undetected lead poisoning. We use these estimates to compare de jure universal screening against targeted screening. Because no policy achieves perfect compliance, we analyze different incremental screening expansions. We estimate that 5,819 untested children had a BLL ≥5µg/dL, in addition to the 18,101 detected cases. 80% of these undetected cases should have been screened under the current policy. Model-based targeted screening can improve upon both the status quo and expanded universal screening.

High blood lead levels of children in a gold mining community in Osun State, Nigeria: an urgent call for action.

BACKGROUND: Environmental exposure from artisanal gold mining activities is a major risk for high blood lead levels (BLLs) in children. Over the last decade, artisanal gold mining activities have been on a sharp increase in some parts of Nigeria. This study compared BLLs of children in the mining community of Itagunmodi and a 50-km distant non-mining community of Imesi-Ile, Osun State, Nigeria. METHODS: This community-based study investigated 234 apparently healthy children, with 117 each from Itagunmodi and Imesi-Ile. Relevant history, examination and laboratory findings including BLLs were recorded and analysed. RESULTS: All participants had BLLs above the cut-off value of 5 µg/dl. However, the mean BLL of subjects living in the gold-mining community (24.2±5.3 µg/dl) was significantly higher than for children in the non-mining area of Imesi-Ile (19.5±6.4 µg/dl; p<0.001). Children in the gold mining community were 3.07 times more likely to have a BLL ≥20 µg/dl than those in the non-mining environment (odds ratio [OR] 3.07 [95% confidence interval {CI} 1.79 to 5.2], p<0.001). Similarly, the odds of having a BLL ≥30 µg/dl was 7.84 times more likely among children living in gold mining Itagunmodi than in Imesi-Ile (OR 7.84 [95% CI 2.32 to 26.46], p<0.0001). BLL was not associated with socio-economic and nutritional status of the participants. CONCLUSIONS: In addition to introduction and enforcement of safe mining practices, regular screening for lead toxicity is advocated for children in these communities.

Using Artificial Intelligence to Identify Sources and Pathways of Lead Exposure in Children.

CONTEXT: Sources and pathways of lead exposure in young children have not been analyzed using new artificial intelligence methods. OBJECTIVE: To collect environmental, behavioral, and other data on sources and pathways in 17 rural homes to predict at-risk households and to compare urban and rural indicators of exposure. DESIGN: Cross-sectional pilot study. SETTING: Knox County, Illinois, which has a high rate of childhood lead poisoning. PARTICIPANTS: Rural families. METHODS: Neural network and K-means statistical analysis. MAIN OUTCOME MEASURE: Children's blood lead level. RESULTS: Lead paint on doors, lead dust, residential property assessed tax, and median interior paint lead level were the most important predictors of children's blood lead level. CONCLUSIONS: K-means analysis confirmed that settled house dust lead loadings, age of housing, concentration of lead in door paint, and geometric mean of interior lead paint samples were the most important predictors of lead in children's blood. However, assessed property tax also emerged as a new predictor. A sampling strategy that examines these variables can provide lead poisoning prevention professionals with an efficient and cost-effective means of identifying priority homes for lead remediation. The ability to preemptively target remediation efforts can help health, housing, and other agencies to remove lead hazards before children develop irreversible health effects and incur costs associated with lead in their blood.

Lead pollution-related health of children in China: Disparity, challenge, and policy.

Lead (Pb) is a neurotoxic metal, and no level of lead exposure is safe for children. China has still experienced problems on child lead poisoning even though the Chinese government has phased out leaded gasoline since 2000. The underlying problem affecting the lead pollution-related health of children in China remains to be comprehensively investigated. It is found that although the significant decline of BLLs, as the Geometric Mean (GM), from 91.40 µg/LGM in 2001 to 37.52 µg/LGM in 2018 is observed, the average BLLs of children are still above 50 µg/L or more [average 59.70 (60.50-65.02, 95 % CI) µg/LGM] after phasing out leaded gasoline since 2000 in China. Lead exposure causes 29.67 MID per 1000 children with a loss of 98.23 (59.40-146.21, 95 % CI) DALYs per 1000 in China, which is greater than the levels reported from the Western Pacific Region and other low- and middle-income countries. A significant correlation is observed between the number of child crimes (NoCCs) and the outcomes of long-term lead exposure for children in China. Although the disparities in BLLs in China are strongly influenced by unequal distributions of potential multi-lead related sources (soil lead, PM2.5 lead, dust lead), unbalance development of local industrialization and economies, as well as incorrect health care for younger children, the notable emissions from coal combustion (CC) and non-ferrous metals (NMS) exploitation dominate the crucial sources of low-level lead exposure to children after phasing out leaded gasoline in China currently. Faced with the unequal and disparate distribution of BLLs in China, the big bottleneck is to decrease the BLLs exertions of 36-45 µg/L in the next few decades. The Chinese government needs to make more efforts on developing more strict guidelines, implementing more policy strategies on prevention and management of blood Pb poisoning, and monitoring the nationwide changes in children's BLLs continuously.

Using blood lead concentrations of wildlife sentinels to identify environmental risk factors of lead exposure for public health and wildlife rehabilitation efforts.

Lead poisoning remains a persistent health issue for both humans and wildlife, despite strides to reduce lead contamination in the environment. Using Geographic Information Systems (GIS), this study explores the associations between blood lead levels (BLLs) in wildlife sentinels and possible built environment lead exposure risk factors in the Minneapolis-Saint Paul, Minnesota urban area. Results show a high-level of heterogeneity in animal BLLs (n = 472) across our urban environment and suggest that each kilometer increase in road density is associated with a 17.07% (95% CI: 1.48%, 35.05%) increase in BLL in our study species of Virginia opossums and Eastern gray squirrels, and a 14.28% (95% CI: 1.16%, 29.09%) increase in BLL of rock pigeons. For squirrels and opossums, we see an additional 5.72% (95% CI: 0.59%, 10.85%) increased risk of BLL for every 1000 people per square-mile. The relationship between animal sentinels and environmental hazards can give us an insight into the potential lead exposure risks for humans. The use of wildlife sentinel data to explore environmental risk factors supports a One Health approach to better address public health questions and aid in wildlife rehabilitation related to residual lead poisoning from ambient environmental exposures.

Neighborhood disparities and the burden of lead poisoning.

BACKGROUND: To assess the persistence of neighborhood-level lead poisoning disparities in Rhode Island. METHODS: Rhode Island Department of Health blood lead levels (BLL) collected from 2006-2019 were linked to census block group rates of poverty and housing built pre-1950. We computed multivariate logistic regression models of elevated BLLs (≥5 µg/dL and ≥10 µg/dL). RESULTS: Of the 197,384 study children, 12.9% had BLLs ≥5 µg/dL and 2.3% had BLLs ≥10 µg/dL. The proportion of children with BLL ≥ 5 µg/dL increased across quintiles of poverty and old housing. The odds ratio for highest quintiles was 1.44 (95% CI: 1.29, 1.60) and 1.92 (95% CI: 1.70, 2.17) for poverty and pre-1950 housing, respectively. A significant temporal decline was observed for BLL ≥ 5 µg/dL (2006: 20.5%, 2019: 3.6%). Disparities narrowed over the study period across quintiles of poverty and old housing with a similar trend appearing in the proportion of children with BLL ≥ 10 µg/dL. CONCLUSION: Despite tremendous progress in reducing lead exposure, substantial neighborhood disparities in lead poisoning persist. These findings provide valuable considerations for primary childhood lead exposure prevention. IMPACT: Through linkage of Rhode Island Department of Health childhood lead poisoning and census data, this study captures neighborhood-level disparities in lead poisoning from 2006-2019. This study demonstrates that the odds of lead poisoning increased in a stepwise fashion for neighborhood quintiles of poverty and housing built pre-1950. While the magnitude of lead poisoning disparities narrowed across quintiles of poverty and old housing, disparities persist. Children's exposure to sources of lead contamination continues to be an important public health concern. The burden of lead poisoning is not equally distributed among all children or communities.

Predicting Low-Level Childhood Lead Exposure in Metro Atlanta Using Ensemble Machine Learning of High-Resolution Raster Cells.

Low-level lead exposure in children is a major public health issue. Higher-resolution spatial targeting would significantly improve county and state-wide policies and programs for lead exposure prevention that generally intervene across large geographic areas. We use stack-ensemble machine learning, including an elastic net generalized linear model, gradient-boosted machine, and deep neural network, to predict the number of children with venous blood lead levels (BLLs) ≥2 to <5 µg/dL and ≥5 µg/dL in ~1 km2 raster cells in the metro Atlanta region using a sample of 92,792 children ≤5 years old screened between 2010 and 2018. Permutation-based predictor importance and partial dependence plots were used for interpretation. Maps of predicted vs. observed values were generated to compare model performance. According to the EPA Toxic Release Inventory for air-based toxic release facility density, the percentage of the population below the poverty threshold, crime, and road network density was positively associated with the number of children with low-level lead exposure, whereas the percentage of the white population was inversely associated. While predictions generally matched observed values, cells with high counts of lead exposure were underestimated. High-resolution geographic prediction of lead-exposed children using ensemble machine learning is a promising approach to enhance lead prevention efforts.

Immigration and Blood Lead Levels Among Asian Populations in the United States: NHANES 2011-2018.

OBJECTIVE: The aim of this study was to explore determinants of high BLLs among the Asian population in the United States. METHODS: We used the US nationally representative National Health and Nutrition Examination Survey (NHANES), 2011-2018. We conducted stratified analyses to compare the BLLs of US-born and non-US-born Asians. We used adjusted linear regression to find predictors of high BLLs. RESULTS: Among 12,563 participants in our analysis, the length of stay in the United States is a predictor of the gradual decrease in BLL among Asian immigrants ( P < 0.05). BLLs of immigrants who stayed in the United States for over 50 years were 0.36 µg/dL (95% confidence interval, 0.07 to 0.66) lower than new immigrants, but still higher than their US-born counterparts. SIGNIFICANCE: Asian population in the US has the highest BLLs among all ethnic groups, and the exposure outside of the US among immigrants is likely the driver.