Blood Lead Levels Research Articles

Mixture analysis of associations between environmental and workplace toxins and liver damage and telomere length, stratified by race/ethnicity

This study aimed to identify the worst “bad actors” in mixtures of pollutants contributing to liver damage and shorter telomeres in the U.S. population, using Weighted Quantile Sum (WQS) modeling with stratification by race/ethnicity. We conducted a comprehensive cross-sectional analysis of mixtures of pollutants in National Health and Nutrition Examination Survey datasets: a) 33,979 adults with blood levels of cadmium (Cd), lead (Pb), and mercury, including subsets with measurements of per-/polyfluoroalkyl substances (PFAS), and polychlorinated biphenyls (PCBs)/polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs); and b) 7360 adults with measurements of telomeres, Cd, and Pb. Multivariable-adjusted WQS regression examined associations between WQS mixture indices and liver injury [alanine aminotransferase (ALT)-elevation], advanced liver-fibrosis (LF), and telomere length. WQSmetal indices were associated with advanced-LF in all racial/ethnic groups. The top contributor was Cd in the total population and in non-Hispanic Whites (NHW), while Pb was the top contributor in non-Hispanic Blacks (NHB). The WQSmetal-PCB-PCDD/F index was associated with ALT-elevation, with PCB126, Cd and Pb as main contributors; the odds ratio (OR) per decile was 1.50 (95%CI, 1.26-1.78), while the OR per decile of the WQSmetal-PFAS index was 1.03 (95%CI, 0.98-1.05), not significant. WQSmetal indices were associated with shorter telomeres. Cd was main contributor associated with advanced-LF in NHW, while Pb was the major bad actor in NHB, suggesting that NHB may be especially susceptible to Pb toxicity. Metals were associated with shorter telomeres. Metal and PCB/PCDD/F mixtures were associated with ALT-elevation. Heavy metals and organic chemicals may contribute to liver-related morbidity and healthcare disparities.

Is Kidney Stone Associated with Thyroid Disease? The United States National Health and Nutrition Examination Survey 2007-2018.

Kidney stones and thyroid disease are two common diseases in the general population, with multiple common risk factors. The associations between kidney stones and thyroid disease are unclear. This study aims to assess the association between 'once had a thyroid disease' and the odds of kidney stones. Adult participants from the National Health and Nutrition Examination Survey (NHANES) 2007-2018 with reliable kidney stone and thyroid disease data were included. Adjusting for age, gender, race, education level, and marital status, diabetes, hypertension, gout, angina pectoris, stroke, and asthma, logistic regression was used to examine the relationship between kidney stones and thyroid illness. Using stratified analysis, the association between thyroid illness and kidney stones was investigated further. Among the participants, 4.9% had kidney stones, and 10.1% had thyroid disease. Kidney stone was associated with thyroid disease (OR=1.441, (95% CI:1.294-1.604), p <0.01), which remained significant (OR=1.166, (95% CI:1.041-1.305), p <0.01) after adjustments with age, gender, race, education level and marital status, diabetes, hypertension, gout, angina pectoris, stroke, and asthma. Stratified by blood lead, blood cadmium, and blood urea nitrogen levels in the human body, the odds of kidney stones still increased with once having a previous thyroid disease. In this large nationally representative survey over 10 years, kidney stone was strongly associated with thyroid disease. In this cross-sectional study, we explored the association between thyroid disease and kidney stones, which may help clinicians intervene in them early.

Heavy metals are liver fibrosis risk factors in people without traditional liver disease etiologies

Liver fibrosis is an important predictor of mortality. Liver disease case definitions changed in 2023. These definitions include an easily over-looked group with no traditional etiology (NTE) of liver disease and no steatosis. We analyzed heavy metals and cardiometabolic risk factors (CMRFs) as fibrosis risk factors in the NTE group and in people with another newly-defined condition, metabolic dysfunction-associated steatotic liver disease (MASLD). Two National Health and Nutrition Examination Survey (NHANES) datasets were analyzed. In NHANES III (1988–1994), fibrosis and steatosis were defined by Fibrosis-4 scores and ultrasound, respectively, in 12,208 adults. In NHANES 2017–2020, fibrosis and steatosis were defined by transient elastography and the controlled attenuation parameter (CAP) in 5525 adults. Fibrosis risk factors varied over time and by race/ethnicity. In the earlier dataset, NTE-fibrosis had a positive, non-significant, association with high blood levels of lead (Pb). MASLD-fibrosis was associated with Pb (OR = 2.5, 95 % CI, 1.4–4.4) and not with CMRFs in non-Hispanic Blacks but was associated with CMRFs in non-Hispanic Whites. Heavy metal exposures fell between the two time periods. In the later dataset, NTE-fibrosis was associated with Pb (OR = 4.2, 95 % CI, 2.6–6.8) and cadmium (OR = 1.8, 95 % CI, 1.1–3.0) in the total population, but not with CMRFs. MASLD-fibrosis was strongly-significantly associated with CMRFs in every racial/ethnic group except non-Hispanic Blacks in whom CMRFs were only weakly associated with MASLD-fibrosis. Heavy metal pollution, which disproportionately impacts minoritized populations, decreased over time, but remained strongly associated with liver fibrosis in people lacking traditional etiological factors for liver disease.

Assessing the Prevalence of Lead Toxicity and Related Factors in Pediatric Patients with Abdominal Pain

Background: Lead toxicity is an environmental disease that has been encountered since ancient times and can present with symptoms such as abdominal pain, constipation, or neurological deficits. This issue accounts for the highest burden among environmental disorders. Objectives: The aim of this study was to assess the prevalence of lead toxicity in patients with abdominal pain in Southern Iran. Methods: In this study, 50 pediatric patients with chronic abdominal pain and 50 healthy individuals were compared in terms of their blood lead levels and underlying demographic information that could contribute to lead toxicity. Results: A total of 100 participants were enrolled in this study, with a mean age of 8.50 ± 2.444 years, 53.0% of whom were male. The mean blood lead levels in the control and case groups were 1.54 ± 0.693 and 2.73 ± 2.547 µg/dL, respectively, with a statistically significant difference (P = 0.002). When cutoff values of 2 µg/dL and 3.5 µg/dL were considered for lead toxicity, the prevalence of lead toxicity was significantly higher in the case group. Environmental and demographic factors did not differ between patients with lead toxicity and those with normal lead levels (P &gt; 0.05). Conclusions: The prevalence of lead toxicity in children complaining of chronic abdominal pain was 12.0% (95% CI: 4.5% - 24.3%). However, more accurate testing of the environment is needed in future studies.

Evaluation of Lead and Cadmium Levels in Individuals Exposed to Cement Dust

Background: Heavy metals such as lead and cadmium, which are present in cement dust, are elements with a density of more than 5 g/cm3 that are harmful to both the environment and living creatures. This study was set out to evaluate levels of lead and cadmium in individuals exposed to cement dust in Nnewi metropolis. Study Design: This case-control study was carried out among male and female workers in cement depots in Nnewi metropolis who were selected by simple random sampling. Methods: Thirty-five individuals exposed to cement dust defined as test participants and thirty-five individuals not exposed to cement dust defined as control participants within the age range of 18 and 51 years were selected into this study. Test participants were sub-grouped based on years of exposure to cement dust into 3 years and below, 4 to 6 years and 7 years and above. Five millilitres of whole blood was collected from each selected participant and levels of lead and cadmium were determined using atomic absorption spectrometry. Data were analysed using Independent Student’s T-test and ANOVA with least significant difference post hoc. Data was presented as mean ± standard deviation and significance level was taken at p&lt; 0.05. Results: The blood levels of lead and cadmium in test participants were significantly higher than blood levels in control participants. The lead levels were significantly higher in test participants exposed to cement dust for 7 years and above than in test participants exposed to cement dust between 4 to 6 years and test participants exposed to cement dust for 3 years and below (p&lt;0.001). There was no significant difference in serum levels of cadmium between test participants exposed to cement dust for 3 years and below, test participants exposed to cement dust between 4 years to 6 years and test participants exposed to cement dust for 7 years and above (p&gt;0.05). Conclusion: Occupational exposure to cement dust causes high blood levels of lead and cadmium in the body and this accumulation is dangerous to health.

Evidence of turmeric adulteration with lead chromate across South Asia

Food adulteration with toxic chemicals is a global public health threat. Lead chromate adulterated spices have been linked with lead poisoning in many countries, from Bangladesh to the United States. This study systematically assessed lead chromate adulteration in turmeric, a spice that is consumed daily across South Asia. Our study focused on four understudied countries that produce >80 % of the world's turmeric and collectively include 1.7 billion people, 22 % of the world's population. Turmeric samples were collected from wholesale and retail bazaars from 23 major cities across India, Pakistan, Sri Lanka, and Nepal between December 2020 and March 2021. Turmeric samples were analyzed for lead and chromium concentrations and maximum child blood lead levels were modeled in regions where samples had detectable lead. A total of 356 turmeric samples were collected, including 180 samples of dried turmeric roots and 176 samples of turmeric powder. In total, 14 % of the samples (n = 51) had detectable lead above 2 μg/g. Turmeric samples with lead levels greater than or equal to 18 μg/g had molar ratios of lead to chromium near 1:1, suggestive of lead chromate adulteration. Turmeric lead levels exceeded 1000 μg/g in Patna (Bihar, India) as well as Karachi and Peshawar (Pakistan), resulting in projected child blood lead levels up to 10 times higher than the CDC's threshold of concern. Given the overwhelmingly elevated lead levels in turmeric from these locations, urgent action is needed to halt the practice of lead chromate addition in the turmeric supply chain.

Determinant Factors of Children's Blood Lead Levels in Java, Indonesia

IntroductionLead poisoning contributes to a significant burden of disease as a toxic substance found in air, soil, and water. In Indonesia, the risk of exposure is high due to the inappropriate recycling of used lead batteries. The objective was to investigate the factors that influence lead levels in children's blood. MethodsThis cross-sectional study assessed blood lead levels (BLLs) in children aged 12–59 months in four communities exposed to used lead-acid batteries (ULABs) recycling activities, comparing them to a control area. The study employed a threshold level of 20 μg/dL to identify high BLLs and utilized a sample size of 324 children from exposed sites and 240 from control sites. Questionnaires, blood lead tests and a home-based assessment for environmental exposures were applied. ResultsThe study participants comprised 295 boys and 269 girls, with an average age of 35 months. Significant disparities in soil lead concentrations median: Q1-Q3 were found between exposed (6581.7 : 2432.6–16647.1) ppm and control areas (253.5 : 158.8–417.1) ppm. Children in exposed areas had 3.9 times higher odds of BLL ≥20 μg/dL. Fathers with BLL ≥20 μg/dL had children with similarly elevated BLLs. Multivariate analysis identified socioeconomic status, study areas, environmental factors (cookware, food ware, spices, house cleaning), and children's behavior (breastfeeding duration) as determinants of elevated BLLs. Reported environmental factors had notable impact on BLLs, with aluminum cookware (aOR = 1.4, 95%CI [1.2–1.6]), food ware materials (aOR = 1.15, 95%CI [1.0–1.3]), type of spices (aOR = 2.7, 95%CI [1.7–48.0]), and house cleaning method (aOR = 2.9, 95%CI [1.2–7.1]). ConclusionThis study highlighted key risk factors affecting children's blood lead levels (BLL) and emphasized the urgency of employing effective strategies to remediate lead-contaminated soils in exposed regions. The findings underscore the need for prompt medical intervention and monitoring for children in these areas, with additional research essential to fully understand lead poisoning pathways in the environment.

Childhood Lead Exposure Linked to Apple Cinnamon Fruit Puree Pouches - North Carolina, June 2023-January 2024.

Lead exposure is toxic even at low levels, resulting in impairments that can affect a child's lifelong success. In North Carolina, testing for lead is encouraged for all children at ages 1 and 2 years and required for children covered by Medicaid; investigations are performed to identify potential exposure sources for children with blood lead levels (BLLs) ≥5 μg/dL. During June-August 2023, routine lead testing identified four asymptomatic North Carolina children with BLLs ≥5 μg/dL. Home investigations identified only WanaBana brand apple cinnamon fruit puree pouches as a potential exposure source; product samples contained 1.9-3.0 ppm of lead. An expanded nationwide investigation led to identification of approximately 500 cases of childhood lead exposure believed to be linked to consumption of apple cinnamon purees, including 22 cases in North Carolina. Fewer than one half (45%) of the 22 North Carolina cases were among children covered by Medicaid. A coordinated multiagency communication strategy was implemented in North Carolina to notify consumers of the hazard and provide recommendations for preventing further exposure. The Food and Drug Administration issued a nationwide public health advisory on October 28, 2023; 2 days later, the manufacturer issued a voluntary recall. Routine testing of young children for lead exposure, combined with thorough environmental investigations, can identify emerging sources of lead exposure and limit further harm.

A novel indicator for lead poisoning beyond blood lead level: Facile diagnosis of lead poisoning using random urine with point-of-care testing

Lead (Pb) poisoning is estimated to account for 1 % of the global disease burden. The gold standard for diagnosing lead poisoning in human body relies on blood lead level (BLL), which is always performed in hospitals using expensive instruments. However, there are still many countries and regions with a lack of medical resources (without enough professional medical staff and analytical instruments). To achieve a facile diagnosis of lead poisoning by ordinary residents (without any expertise), this study conducted a research study on 810 participants to discover and validate a new lead poisoning indicator (creatinine-corrected urinary lead level, cULL) beyond BLL in non-invasive samples. A point-of-care testing (POCT) device to measure cULL was developed, equipped with liquid-phase microextraction and electromembrane extraction on a paper-based analytical device for on-site separation of lead and creatinine in the urine, using a smartphone for the quantification of analytes. The cULL as a novel indicator and the POCT device developed could be effective in reducing the risk of damage from lead contamination.

Association between blood lead levels and parathyroid hormone among United States adolescents aged 12-19: a cross-sectional study.

Studies on the association between serum lead levels and parathyroid function in adolescents are lacking. Therefore, in this study, we elucidated the possible association between blood lead levels (BLLs) and the parathyroid hormone (PTH) in adolescents aged 12-19 years in the United States. In this study, information from the database of the National Health and Nutrition Examination Survey was utilized. The study included 3919 participants from survey cycles between 2003-2004 and 2005-2006. Multivariable linear regression analysis was performed to determine the correlation between BLLs and PTH. Furthermore, smooth curve fitting was utilized to analyze the dose-response relationship between BLLs and PTH. Multivariable linear regression analysis revealed that every 1 μg/dL increase in BLLs was associated with 0.67 pg/mL increase in PTH (β = 0.67, 95% CI: 0.16-1.18, p < 0.01). However, sex-stratified subgroup analysis revealed that this positive association was only observed in males (β = 1.16, 95% CI: 0.50-1.83 p < 0.01). Smooth curve fitting revealed a positive correlation between BLLs and PTH. In adolescents in the United States, BLLs are positively correlated with PTH, particularly in males.

The relationships between blood lead levels and nocturia prevalence in adults: A retrospective study.

The purpose of this study was to examine the association between blood lead levels and the prevalence of nocturia in American adults. We analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2020, focusing on individuals aged 20 years or older (n = 11,919). Blood lead levels were categorized into two groups (<2 µg/dL and ≥2 µg/dL), and the presence of nocturia was assessed based on questionnaire responses. We used multivariable logistic regression models to explore the association between blood lead levels and nocturia while adjusting for various covariates, including sex, ratio of family income to poverty (RIP), lipid profile, age, body mass index (BMI), race, citizenship, sleep trouble, diabetes, and hypertension. To verify whether certain covariates influence blood lead levels and the risk of nocturia, we conducted subgroup analyses. Of the study participants, 31.70% reported experiencing nocturia. Individuals with higher blood lead levels (≥2 µg/dL) exhibited a higher likelihood of experiencing nocturia compared to those with lower levels (<2 µg/dL) in all three models (Model 1: OR 1.46, 95% CI 1.29-1.66, p < 0.0001; Model 2: OR 1.25, 95% CI 1.09-1.44, p = 0.002; Model 3: OR 1.22, 95%CI 1.06-1.41, p = 0.01). Subgroup analyses revealed that factors such as age, sex, sleep trouble, diabetes, hypertension, BMI, RIP, and race did not affect the association between blood lead levels and the risk of nocturia (P for interaction >0.05). This study reported the correlation between blood lead levels and nocturia. We found that compared to blood lead levels below 2 µg/dL, when lead levels reached or exceeded 2 µg/dL, the risk of nocturia occurrence increased by 22%. This study is based on existing data from a public database and not from a specific clinical trial; hence, clinical registration information is not provided.

Lead in umbilical cord blood and associated factors in Casablanca Morocco: A preliminary results

BackgroundLead is the most common toxic metal to which Moroccans are exposed. Given the susceptibility of the fetus to lead, it is crucial to assess prenatal lead exposure. However, in Morocco, no study has assessed prenatal exposure to lead. The main goals of the present study are to determine lead concentration in umbilical cord blood and identify risk factors for prenatal lead exposure in Casablanca, Morocco. MethodsTo achieve these purposes, 87 cord blood lead samples were collected from mothers-baby pairs from January to December 2019. Indeed, a structured questionnaire was used to collect socio-demographic characteristics, obstetric data, leisure, cultural habits, and environmental information. Cord blood lead level was analyzed by inductively coupled plasma-mass spectrometry. ResultsThe median lead concentration was 4.902 µg/dl with a minimum and maximum of 0.833 µg/dl and 23.593 µg/dl, respectively. A high proportion of the newborns (65.52 %) had cord blood lead levels above the Centers for Disease Control (CDC) allowable threshold limit (3.5 µg/dl). Statistical analysis was performed to assess the association between blood levels and the above factors. Lead levels in cord blood were significantly associated with the maternal educational level, anemia history, delivery mode, passive smoking during pregnancy as well as with the frequency of consumption of tea. ConclusionThis study provides the first data on lead levels in newborns. Cord blood lead levels were high in the majority of the participants, these results reinforce the need to establish health surveillance programs in Morocco.

Low levels of potentially toxic elements in workers are associated with self-reported health outcomes

Occupational exposure to toxic elements can adversely affect health. The current study evaluated blood concentrations of potentially toxic elements (PTE) including As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, and Zn in formal and informal workers. Additionally, the study investigated the associations between blood PTE concentrations and reported health outcomes in the study population. The exposed group included women engaged in informal jewelry welding within their homes in Limeira, São Paulo state, Brazil (n = 36) and men who worked at a steel company in Volta Redonda, Rio de Janeiro state, Brazil (n = 22). The control group comprised residents of the same neighborhoods as the workers but without occupational exposure to chemicals (n = 28 in Limeira; n = 27 in Volta Redonda). Triple Quadrupole Inductively Coupled Plasma Mass Spectrometry (TQ ICP-MS) was used to determine PTE concentrations in blood samples. Glycemia, insulin, and lipid profile tests were performed. All participants completed questionnaires on household risk and reported morbidity. The blood concentrations of Cd, As, and Pb, as well as glycemia, were higher in informal workers than in control subjects. No significant differences were observed between formal workers and control subjects. A robust Poisson regression model, adjusted for variables suggested by a Directed Acyclic Graph, disclosed associations of blood lead and arsenic concentrations with the prevalence of neurological manifestations in Limeira. Blood lead levels > 2.6 μg dL−1 were associated with 2.3 times the prevalence of self-reported neurological manifestations (95 % CI: 1.17–4.58; p = 0.02) than lower blood lead concentrations. Furthermore, a positive association between blood cadmium concentrations and glycemia was observed. Informal occupational exposure to these elements may indicate an increased risk of developing diseases. Monitoring exposure and implementing interventions to reduce PTE exposure in the work environment represent significant steps toward prevention.

Blood Lead Mediates the Relationship between Biological Aging and Hypertension: Based on the NHANES Database.

Hypertension remains a major global public health crisis due to various contributing factors, such as age and environmental exposures. This study delves into exploring the intricate association between biological aging, blood lead levels, and hypertension, along with examining the mediating role of blood lead levels in the relationship between biological aging and hypertension. We analyzed data from two cycles of the NHANES, encompassing 4473 individuals aged 18 years and older. Our findings indicate that biological aging potentially escalates the risk of hypertension and the incidences of systolic blood pressure (SBP) and diastolic blood pressure (DBP) abnormalities. Utilizing weighted quantile sum (WQS) and quantile g-computation (QGC) model analyses, we observed that exposure to heavy metal mixtures, particularly lead, may elevate the likelihood of hypertension, SBP, and DBP abnormalities. Further mediation analysis revealed that lead significantly mediated the relationship between biological aging and hypertension and between biological aging and SBP abnormalities, accounting for 64% (95% CI, 49% to 89%) and 64% (95% CI, 44% to 88%) of the effects, respectively. These outcomes emphasize the criticality of implementing environmental health measures.

Impact of Cognitive Intervention on Neurocognitive Development of Schoolchildren Exposed to Lead in a Semi-Urban Community in Mexico.

A quasi-experimental study with a control group was conducted in children aged 7 to 12years from 2 communities in Morelos, Mexico. Blood lead levels were determined, and the neurocognitive function was assessed pre- and postintervention with the Wechsler Intelligence Scale for Children and Children's Auditory Verbal Learning Test-2. A cognitive intervention was conducted at the school. The difference-in-differences method adjusted for variables known as priori and evaluated the impact of cognitive intervention. The differences-in-differences models indicated a significant average increase in scores on the Verbal Comprehension Index (9.58 points), Processing Speed Index (5.33 points), intelligence quotient (5.63 points) level of learning (7.66 points), interference trial (10.12 points), immediate memory span (7.98 points), and recognition accuracy (1.18 points) subtests after the cognitive intervention. The results suggest that cognitive intervention improves neurocognitive development in schoolchildren exposed to Pb.

Assessment of prevalence of elevated blood lead levels and risk factors among children and pregnant women in Bihar, India

BackgroundWhile modeled estimates and studies in contaminated areas indicate high lead exposure among children in Bihar, India, local data on lead exposure in the child population is limited. ObjectivesTo characterize lead exposure, and assess potential sources of lead exposure among a state-representative sample of children and their pregnant mothers residing in Bihar. MethodsBlood samples were collected from 697 children under five and 55 pregnant women from eight districts in Bihar. Blood lead levels were determined using capillary blood and a portable lead analyzer. Household demographics, home environment, behavior, and nutrition information were collected through computer-assisted personal interviews with primary caregivers. Logistic regression was used to assess associations between potential risk factors and elevated blood lead levels. ResultsMore than 90% of children and 80% of pregnant women reported blood lead levels ≥5 μg/dL. Living near a lead-related industry and pica behavior of eating soil were significantly associated with increased odds of having elevated blood lead levels. Additional risk factors for having a blood level ≥5 μg/dL included the use of skin lightning cream (aOR = 5.11, 95%CI: 1.62, 16.16) and the use of eyeliners (aOR = 2.81, 95%CI: 1.14, 6.93). Having blood lead levels ≥10 μg/dL was also significantly associated with the household member who had an occupation or hobby involving the use of lead (aOR = 1.75, 95%CI: 1.13, 2.72). DiscussionElevated blood lead levels were prevalent among children and pregnant women in Bihar, indicating the urgent need for a comprehensive lead poisoning prevention strategy.

Management of the Work Environment to Reduce Blood Lead (BLL) Levels in the Assay Laboratory

Assay Laboratory in PT Freeport Indonesia's Concentrating Division, especially for conducting fire assay. Litharge (lead oxide) is a reagent used to test mineral levels; the content of precious metals is called Au. Although lead exposure is low, prolonged exposure to lead could accumulate in the human system, resulting in poisoning or toxicity. This study aimed to determine the effect of work environment management in assay laboratories on reducing blood lead levels during fire assay analysis. This research is a quantitative cohort study. The sampling technique used is purposive sampling. Data analysis techniques are used in different tests. Data collection was conducted using laboratory tests to take blood samples once a year regularly for every worker working in the assay laboratory. Based on the results of the different tests, a T value of 5,638 was obtained with a Sig value of 0.011 (α˂5%), so it can be concluded that there was a decrease in blood Pb levels in workers before and after managing the work environment. Recommended exposure standards are floor exposure values for laboratories (other than fire test laboratories) not to exceed 2.2 mg/m2 (200 μg/ft2) and surface in dining areas not to exceed 0.43 mg/m2 (40 μg/ft2). Improving working environment conditions by procuring a laundry system and lockers, procuring more than one laboratory coat, procuring sinks in every corner of the laboratory, and having special soap for washing hands has proven to be able to reduce Pb exposure rates in assay laboratories from 2019 to 2022.

A Snapshot of Lead in Consumer Products Across Four US Jurisdictions.

Following the removal of lead from gasoline, paint and pipes were thought to be the main sources of lead exposure in the United States. However, consumer products, such as certain spices, ceramic and metal cookware, traditional health remedies, and cultural powders, are increasingly recognized as important sources of lead exposure across the United States. This paper reviews data from four US jurisdictions that conduct in-home investigations for children with elevated blood lead levels (BLLs) to examine the prevalence of lead exposures associated with consumer products, in comparison with housing-related sources. Authors reviewed investigation data (2010-2021) provided by California, Oregon, New York City, and King County, Washington, and compared the extent of lead exposures associated with housing-related vs. consumer products-related sources. The proportion of investigations identifying consumer products-related sources of lead exposure varied by jurisdiction (range: 15%-38%). A review of US CDC and US FDA alerts and New York City data indicates that these types of lead-containing products are often sourced internationally, with many hand carried into the United States during travel. Based on surveillance data, we believe that US immigrant and refugee communities are at an increased risk for lead exposures associated with these products. To engage health authorities, there is a need for evidentiary data. We recommend implementing a national product surveillance database systematically tracking data on consumer products tested by childhood lead poisoning prevention programs. The data repository should be centralized and accessible to all global stakeholders, including researchers and governmental and nongovernmental agencies, who can use these data to inform investigations. Effectively identifying and addressing the availability of lead-containing consumer products at their source can focus resources on primary prevention, reducing lead exposures for users abroad and in the United States. https://doi.org/10.1289/EHP14336.

Improving prediction of linear regression models by integrating external information from heterogeneous populations: James-Stein estimators.

We consider the setting where (1) an internal study builds a linear regression model for prediction based on individual-level data, (2) some external studies have fitted similar linear regression models that use only subsets of the covariates and provide coefficient estimates for the reduced models without individual-level data, and (3) there is heterogeneity across these study populations. The goal is to integrate the external model summary information into fitting the internal model to improve prediction accuracy. We adapt the James-Stein shrinkage method to propose estimators that are no worse and are oftentimes better in the prediction mean squared error after information integration, regardless of the degree of study population heterogeneity. We conduct comprehensive simulation studies to investigate the numerical performance of the proposed estimators. We also apply the method to enhance a prediction model for patella bone lead level in terms of blood lead level and other covariates by integrating summary information from published literature.

Childhood blood-lead level predicts lower general, non-selective hippocampal subfield volumes in midlife

Millions of adults and children are exposed to high levels of lead, a neurotoxicant, each year. Recent evidence suggests that lead exposure may precipitate neurodegeneration, particularly if the exposure occurs early or late in life, with unique alterations to the structure or function of specific subfields of the hippocampus, a region involved in memory and Alzheimer’s disease. It has been proposed that specific hippocampal subfields may thus be useful biomarkers for lead-associated neurological disease. We turned to a population-representative New Zealand birth cohort where the extent of lead exposure was not confounded by social class (the Dunedin Study; born 1972–1973 and followed to age 45) to test the hypothesis that early life lead exposure (blood-lead level at age 11 years) is associated with smaller MRI-assessed gray matter volumes of specific subfields of the hippocampus at age 45 years. Among the 508 Dunedin Study members with childhood lead data and adult MRI data passing quality control (93.9 % of those with lead data who attended the age-45 assessment wave, 240[47.2 %] female), childhood blood-lead levels ranged from 4 to 31 µg/dL (M[SD]=10.9[4.6]). Total hippocampal volumes were lower among adults with higher childhood blood-lead levels (b=-102.6 mm3 per 5 ug/dL-unit greater blood-lead level, 95 %CI: −175.4 to −29.7, p=.006, β=-.11), as were all volumes of the 24 hemisphere-specific subfields of the hippocampus. Of these 24 subfields, 20 demonstrated negative lead-associations greater than β=-.05 in size, 14 were statistically significant after adjustment for multiple comparisons (pFDR<.05), and 9 remained significant after adjustment for potential confounders and multiple comparisons. Children exposed to lead demonstrate smaller volumes across all subfields of the hippocampus in midlife. The hypothesis that lead selectively impairs specific subfields of the hippocampus, or that specific subfields may be markers for lead-associated neurological disease, requires further evaluation.