Lead Exposure Research Articles

Trend Analysis of the Burden of Hypertensive Heart Disease in China from 1990 to 2021

Objective: To quantitatively analyze the burden of hypertensive heart disease (HHD) in China and provide a scientific basis for prevention and control strategies. Methods: Data from the Global Burden of Disease 2021 database were used to assess the disease burden, deaths, years lived with disability (YLDs), and risk factors for HHD in the Chinese population from 1990 to 2021. Results: From 1990 to 2021, HHD cases in China increased from 1.5 million to 3.9 million, with an average annual growth rate of 2.83%. Prevalence rose from 127.76/100,000 to 259.00/100,000, while age-standardized prevalence decreased by 0.68% annually. HHD deaths increased from 232,478 to 320,247, with a mortality rate rise from 19.76/100,000 to 22.56/100,000, though age-standardized mortality decreased by 2.68% annually. YLDs rose from 124,386 to 301,426, with the rate increasing by 2.20% annually, while age-standardized YLDs decreased by 0.67% annually. High sodium intake and low fruit consumption were key risk factors for HHD deaths. Deaths related to low vegetable intake decreased until 2005 and then rose, while deaths from lead exposure showed a similar pattern. Conclusion: HHD cases and prevalence increased significantly, but age-standardized prevalence and mortality rates declined, reflecting the impact of an aging population and improved health interventions. The rise in YLDs highlights the long-term impact on patients’ quality of life. Key risk factors included high sodium intake and low fruit consumption, emphasizing the importance of dietary improvements in HHD prevention. HHD remains a significant public health challenge in China, requiring continuous research and targeted prevention strategies.

Diet quality and blood lead levels in Uruguayan first graders

ObjectiveFoods are a potential source of lead but also contain nutrients that counteract the intestinal absorption of lead. Translatable evidence is needed to better understand the relationship between whole diets and blood lead levels (BLLs) in children. In this cross-sectional study we investigated the association between dietary variety, adequacy, moderation, and overall diet quality with children's BLLs. MethodsFirst graders (~ 7 years) from Montevideo, Uruguay were evaluated in years 2009–13 (Phase I, n = 303) and 2015–19 (Phase II, n = 443). Lead was measured in fasting blood via atomic absorption spectrometry and primary caregivers completed two non-consecutive 24-h recalls. Indices of dietary variety (maximum score of 20), adequacy (maximum 40), moderation (maximum 30), and overall diet quality were calculated from food and nutrient intakes averaged over two recall days. The indices were adapted from the Diet Quality Index-International based on dietary recommendations for children. Missing covariate data were imputed. The associations between diet quality measures and BLLs were modeled separately in Phase I and II with multivariable linear models, testing for sex differences via interaction terms and stratified models. ResultsThe median[IQR] BLLs were 3.8[2.6, 4.9] and 1.3[0.7, 3.6] μg/dL in study Phases I and II, respectively. All diet quality scores were <60 % of the maximum values and daily intakes of key food groups fell below recommended levels. There was little evidence of an association between measures of diet quality and children's BLLs overall. On the other hand, higher diet variety, adequacy, and overall diet quality were associated with slightly higher BLLs among girls in Phase I only. ConclusionsIn the context of low lead exposure and food consumption patterns that fall short of recommended levels, the relation of diet quality to children's BLLs may depend on lead exposure levels.

Assessment of immune status markers during occupational lead exposure

The immune system is sensitive to the effects of environmental factors, and according to numerous studies, lead has an immunotoxic effect. At the same time, there is evidence of the multidirectional nature of the impact of lead on the immune system, determined by the degree of exposure to this heavy metal, which makes it current to study changes in immunological markers in workers of a modern lead recycling plant, taking into account levels and complexity of exposure. In the era of personalized medicine, monitoring the potential influence of occupational factors exposure on the immune system can facilitate a personalized approach to the prevention of work-related health conditions. The aim of the study: to evaluate changes in immune status markers among employees of lead recycling plant. The main group – 62 men working at a lead recycling plant, the control group – 47 men not exposed to occupational factors. Laboratory examination included a determination of the lead blood level, a clinical blood test, the serum levels of IL- 1â, IL- 10, IL- 8, MCP-1, C3 and C4 complement components, IgA, IgM, IgG. In the main group, compared to the control group, a higher number of neutrophils, lymphocytes, monocytes, higher levels of IL-8, C3 and C4 components of the complement system, and lower levels of IgM were detected. In the main group, the following changes in markers were significantly more often detected in comparison with reference values: an increase in the C3 component of complement (51.6% in the main group compared to 12.5% in the control group), decreased IgG (24.2% compared to 6.2%) and increased IgA (22.6% compared to 6.2%). Associations were identified between the lead blood level and the number of lymphocytes, the level of IgG, between work experience in contact with lead and the level of MCP-1 and C3 complement components. The results of the studies revealed the presence of changes in the immune status markers of workers at a lead recycling plant, which demonstrate a proinflammatory effect of lead and an influence on the humoral immune status. The identified changes in immunological parameters may underlie the mechanisms of formation of pathological conditions associated with lead exposure, which determines the relevance of continuing research to assess dynamic changes in immunological parameters and develop a system for monitoring the immune status of workers exposed to lead and its compounds to optimize preventive measures.

Comparative study on the immune surveillance injury of blood cerebrospinal fluid barrier induced by exposure to lead acetate and nano-lead sulfide

Objective: To investigate the differences in terms of blood cerebrospinal fluid barrier immune surveillance injury by lead acetate and nano-lead sulfide exposure in order to provide basis for the study of their mechanism of nerve injury caused by exposure to lead and nano lead. Methods: In June 2015, forty-five SPF SD male rats were randomly divided into control group, lead acetate group (20 mg/kg) and nano-lead sulfide group (20 mg/kg), with 15 rats in each group. The rats were intragastric five times a week, for nine weeks. The numbers of CD4(+) T lymphocytes in blood and cerebrospinal fluid were detected by flow cytometry. The levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) in serum and cerebrospinal fluid were detected by ELISA. The expressions and distribution of intercellular cell adhesion molecule-1 (ICAM-1) and CD4(+) T lymphocytes in choroid plexus were detected by laser confocal fluorescence immunoassay. The mRNA expression levels of IL-4, IFN-γ and ICAM-1 in the choroid plexus were detected by real-time PCR. Results: Compared with the control group, the proportion of CD4(+) T lymphocytes in blood of rats in lead acetate group was increased, the proportions of CD4(+) T lymphocytes in cerebrospinal fluid of rats in lead acetate group and nano-lead sulfide group were increased, the contents of IL-4 and IFN-γ in serum of rats in lead acetate group and nano-lead sulfide group were increased, the content of IL-4 in cerebrospinal fluid of rats in lead acetate group and the contents of IL-4 and IFN-γ in cerebrospinal fluid of rats in nano-lead sulfide group were increased, the differences were statistically significant (P<0.05). The fluorescence intensity of ICAM-1 and CD4(+) T lymphocytes in choriochoroid plexus of rats in lead acetate group and nano-lead sulfide group were stronger than those in control group, and the fluorescence intensity of CD4(+) T lymphocytes of rats in nano-lead sulfide group was weaker than that in lead acetate group. Compared with the control group, the mRNA expression levels of ICAM-1, IL-4 and IFN-γ in choriochoroids plexus of rats in lead acetate group and nano-lead sulfide group were increased, and the mRNA expression levels of ICAM-1 and IL-4 in nano-lead sulfide group were higher than those in lead acetate group, while the mRNA expression level of IFN-γ in nano-lead sulfide group was lower than that in lead acetate group (P<0.05) . Conclusion: Exposure to lead and nano-lead sulfide can cause the increase of CD4(+) T lymphocytes, IL-4, IFN-γ and ICAM-1, which may be related to the damage to the immune surveillance of the blood cerebrospinal fluid barrier. And there is a difference in the injury caused by lead and nano-lead sulfide exposure.

Lead exposure of a fossorial rodent varies with the use of ammunition across the landscape

Exposure to heavy metals has been documented in a wide range of wildlife species, but infrequently in ground squirrels. This is despite their tendency to be targets of recreational shooters and the accumulation of lead ammunition in the soil environments they inhabit. We analyzed lead and copper concentrations in liver (nPb = 116, nCu = 101) and femur (nPb = 116, nCu = 116) of Piute ground squirrels (Urocitellus mollis) and in soil (n = 75) on public lands in southwestern Idaho to understand how lead exposure may vary across a gradient of intensities and histories of shooting activity. The liver and femur of squirrels from areas used for recreational shooting for >30 years had elevated lead concentrations relative to areas where shooting was rare or did not occur (our negative control), but as expected, lower than areas used for military target training for >70 years (our positive control). Lead concentration in soils were higher in areas used for military target training than in those used for recreational shooting. There were no differences in copper concentrations in biological or soil samples among sites. These data suggest that ground squirrels can be influenced by the history of lead use in their local environment, and they illustrate another pathway by which human activity can influence toxicant exposure to wildlife.

MORPHOLOGY OF THE HEART IN THE DELAYED PERIOD OF EXPOSURE TO LOW DOSES OF LEAD

The aim of this study was to investigate the delayed effects of low doses of lead exposure on the hart using an original experimental model for studying the delayed effects. Analysis of the obtained morphological picture revealed structural abnormalities affecting both the muscular and stromal-vascular components. The degree of damage is in direct correlation with the received dose of lead. The above indicates that lead loading, even in low doses, is accompanied by structural abnormalities in the heart even after a long time. Most likely, this is due to the ability of lead to accumulate in the body and remain there for a long time. Vascular disorders play a certain, if not the main, role in the damage to muscle cells. However, the presence of a complex mechanism, which also implies primary damage to cardiomyocytes under the influence of lead, cannot be ruled out. Due to the properties of lead and its impact on the body, and also due to the fact that it is impossible to stop the spread of lead in nature, it is important, along with the study of the mechanisms and results of lead exposure, to find prophylactic means that displace lead ions from the body and regulate metabolism, which is affected by their activity.

Loss of cognitive function in Mexican children due to lead exposure and the associated economic costs

BackgroundLead exposure reduces the cognitive development and future economic prospects of children. While previous studies in high-income settings have explored productivity losses associated with lead exposure, limited research has focused on low and middle-income countries like Mexico. ObjectivesThis study aims to provide a comprehensive assessment of the economic implications of lead exposure on Mexican children using, for the first time, nationally representative Blood Lead Levels (BLLs) measurements in children aged 1–4, specifically focusing on the costs of forgone lifetime income due to cognitive losses. MethodsBLLs of children aged 1–4 were extracted from the 2018–2019 National Health and Nutrition Survey (ENSANUT). Estimations of cognitive losses were derived from a log-linear relationship between BLLs and IQ loss. Lost lifetime economic productivity per child was calculated, assuming a 2% reduction in lifetime potential productivity for each IQ point lost due to lead exposure, based on previous literature (Attina and Trasande, 2013; Larsen and Sánchez-Triana, 2023). Productivity data were obtained from representative sources for Mexico. ResultsThe estimated economic loss amounted to US $33.02 billion, equivalent to 2.76% of Mexico's Gross Domestic Product (GDP) in 2019 (calculated for a 1-year cohort). On a national scale, the long-term loss of cognition for children 1–4 years old is 4.14 IQ points per child due to lead exposure, with significant variability across States (range: 3.26 to 5.26). Lead-poisoned children (≥5 μg/dL) suffered an average loss of 6.42 IQ points (range: 0 to 6.97). In terms of economic impact, some States like Chiapas experienced losses of 7.08% of its GDP, while others had losses as low as 0.67%. Intriguingly, states with lower Human Development Index (HDIs) exhibited relatively higher economic losses despite lower average blood lead levels. DiscussionThe heterogeneous impact of lead exposure across Mexican states underscores the necessity for tailored regional policies. These findings emphasize the urgency for targeted interventions and informed policy measures to mitigate the socioeconomic consequences of lead exposure on Mexican children.

Childhood lead exposure and sleep problems in adolescents: a longitudinal cohort study.

Childhood lead exposure is linked to poorer neurobehavioral function in adolescence, but the relationship between lead and adolescent sleep health remains inconsistent. This study aimed to investigate concurrent and longitudinal associations between lead exposure and multiple sleep health domains in adolescents. A total of 972 adolescents from China Jintan Child Cohort were included in analyses. The Blood lead levels (BLLs) were assessed in two Waves, at ages 3-5years (mean 6.50 ± 2.76μg/dL) and 11-13years (mean 3.12 ± 1.17μg/dL). Sleep problems at age 11-13 were parent-reported via the Child Sleep Health Questionnaire (CSHQ) and self-reported by adolescents using the Pittsburgh Sleep Quality Index (PSQI). Both early and later BLLs were associated positively with parental reported sleep problems, including sleep onset delay, night waking, short duration, parasomnias, and disordered breathing. Sex-stratified analyzes showed that most adjusted associations between two-Wave BLLs and sleep outcomes (CSHQ and PSQI) remained statistically significant in males, with a minor increase in the magnitude of these associations. The association between Wave II BLLs and shorter self-reported sleep duration was only statistically significant in female adolescents. Compared to children with consistently low BLLs at both ages, those with persistently high BLLs at both ages had significantly shorter parental-reported sleep duration and worse sleep onset delay. Findings suggest that both early and later childhood lead exposures link to more adolescent sleep problems, with recent BLLs showing stronger associations with poor adolescent sleep health reported by their parents.

Bone lead measurements of live condors in field to assess cumulative lead exposure.

Lead poisoning remains the leading cause of diagnosed death for critically endangered California condors, which are annually monitored for lead exposure via blood tests. Blood tests are generally reflective of acute lead exposure. Since condors are victims to both chronic and acute lead exposure, measuring bone, which in humans is reflective of years to decades worth of exposure, is a valuable biomarker. In this study, we measured bone Pb of the tibiotarsus of 64 condors in vivo using a portable x-ray fluorescence device. The average uncertainty for measurements, typically reflective of how effective the device performed, was found to be 3.8 ± 2.2µg/g bone mineral. The average bone lead level was found to be 26.7 ± 24.5µg/g bone mineral. Bone lead correlated significantly with a sum of all blood lead measures over the lifetime of each condor. In the future, bone lead can potentially be used to inform treatment planning and address the chronic health implications of lead in the species.

Engineering a PbrR-Based Biosensor for Cell-Free Detection of Lead at the Legal Limit.

Industrialization and failing infrastructure have led to a growing number of irreversible health conditions resulting from chronic lead exposure. While state-of-the-art analytical chemistry methods provide accurate and sensitive detection of lead, they are too slow, expensive, and centralized to be accessible to many. Cell-free biosensors based on allosteric transcription factors (aTFs) can address the need for accessible, on-demand lead detection at the point of use. However, known aTFs, such as PbrR, are unable to detect lead at concentrations regulated by the Environmental Protection Agency (24-72 nM). Here, we develop a rapid cell-free platform for engineering aTF biosensors with improved sensitivity, selectivity, and dynamic range characteristics. We apply this platform to engineer PbrR mutants for a shift in limit of detection from 10 μM to 50 nM lead and demonstrate use of PbrR as a cell-free biosensor. We envision that our workflow could be applied to engineer any aTF.

Internal blood lead exposure levels in permanent residents of Jiangxi Province and its effects on routine hematological and biochemical indices.

Lead exposure levels are closely linked to human health and can cause damage to multiple organ systems, including the blood system and liver. However, due to insufficient evidence, the effects of lead exposure on hematological and biochemical indices have not been fully established. This study aims to explore the blood lead levels of permanent residents in Jiangxi Province and analyze the factors affecting blood lead levels and the impact of blood lead levels on hematological and biochemical indices. We conducted a cross-sectional study including questionnaires, health examinations, and blood sample examinations on 720 randomly selected permanent residents (3-79 years) in Jiangxi Province in 2018. The blood lead levels were measured using inductively coupled plasma mass spectrometry. Routine hematological and biochemical tests were determined by qualified medical institutions using automated hematology analyzers and biochemistry analyzers. The geometric mean of blood lead concentration in permanent residents of Jiangxi Province was 20.45 μg/L. Gender, age, annual household income, smoking, and hypertension were the influencing factors for blood lead levels. For each 1 μg/L increase in blood lead, the risks of elevated red blood cell count (from low to high), platelet volume distribution width, alkaline phosphatase (from low to high), and cholesterol increased by 2.4, 1.6, 3.6, and 2.3%, respectively, whereas the risks of elevation of direct bilirubin and total bilirubin both decreased by 1.7%. The blood lead level in permanent residents of Jiangxi Province is higher than the national average. Higher blood lead levels were found in men than in women; blood lead levels were positively correlated with age but negatively correlated with annual household income; smoking and hypertension are risk factors for elevated blood lead; and blood lead levels affect routine hematological and biochemical markers such as red blood cell count, platelet volume distribution width, direct bilirubin, total bilirubin, alkaline phosphatase, and cholesterol.

Evaluation of lead exposure effects on tissue accumulation, behavior, morphological and hemato-biochemical changes in common carp, Cyprinus carpio

BackgroundHeavy metal pollution, particularly lead (Pb), poses a significant threat to aquatic ecosystems and their inhabitants, threatening their delicate balance and long-term viability. This study highlights the urgent need to mitigate heavy metal pollution in aquatic ecosystems. ObjectiveThis study investigates Pb(NO3)2 exposure effects on tissue accumulation, behavioral abnormalities, and hemato-biochemical parameters in common carp (Cyprinus carpio), a widely distributed freshwater fish species. MethodologyFish (115 ± 5.23 g) were exposed to various Pb(NO3)2 concentrations for 10 and 20 days, representing control (0 %), 25 %, 50 %, and 75 % of the LC50 equivalent to 19.33, 38.66, and 58.0 mg/l, respectively. The standard manual procedure was used for blood sampling. The lead concentration in fish tissue was determined using an atomic absorption spectrophotometer. ResultsResults revealed that fish gills showed significant (P < 0.05) increase in Pb(NO3)2 after 10 days, further rising after 20 days. Liver concentrations also rose significantly (P < 0.05) with prolonged exposure and increasing Pb levels. Muscle had lower concentrations. Hematological parameters (RBC, WBC, HB, HCT) decreased with higher Pb(NO3)2 levels. Behavioral and morphological changes were significantly more pronounced in the exposure groups when compared to the control group. Hepatic enzyme activities (AST, ALT), glucose, and lipid levels increased, while total protein decreased. ConclusionsThe study highlights Pb(NO3)2 harmful effects on common carp, impacting tissue accumulation, hematological parameters, and biochemical disruptions. It emphasizes the need to monitor and mitigate heavy metal pollution in aquatic environments to safeguard freshwater organisms and ecosystems, and to further increase our understanding of Pb toxicity in freshwater ecosystems.

Pre-natal and early life lead exposure and childhood inhibitory control: an item response theory approach to improve measurement precision of inhibitory control

BackgroundNeurodevelopmental performance tasks are often separately analyzed, even when they tap into a similar construct. This may yield mixed findings for associations of an exposure-neurobehavioral outcome. We develop an item response theory (IRT) approach to integrate multiple task variables together to improve measurement precision of the underlying construct. We apply this approach to create an integrative measure of childhood inhibitory control, and study impacts of pre/post-natal lead exposure.MethodsUsing data from a prospective cohort based in Mexico (N = 533), we created an inhibitory control scale that integrates accuracy and reaction time information from four inhibitory control tasks (Go/NoGo Letter, Go/NoGo Neutral, Go/NoGo Happy, Delis-Kaplan Executive Function System (D-KEFS) Color-Word Interference Test, Condition 3). Using a generalized partial credit item response theory model, we estimated an inhibitory control index for each participant. We then assessed adjusted associations between umbilical cord blood and 4-year lead and childhood inhibitory control. We developed a resampling approach to incorporate error estimates from the inhibitory control variable to confirm the consistency of the lead-inhibitory control associations. We modeled time-varying associations of lead with each inhibitory control measure separately.ResultsParticipants had a median age of 9 years; 51.4% were males. Umbilical cord blood [-0.06 (95% CI: -0.11, -0.01)] and 4-year lead [-0.07 (95% CI: -0.12, -0.02)] were associated with inhibitory control index at 8–10 years. A resampling approach confirmed that 4-year lead was consistently associated with childhood inhibitory control index. Umbilical cord blood and 4-year lead were each associated with 3 out of 8 measures in separate models.ConclusionThis is the first application of IRT in environmental epidemiology to create a latent variable for inhibitory control that integrates accuracy and reaction time information from multiple, related tasks. This framework can be applied to other correlated neurobehavioral assessments or other phenotype data.

Predicting blood lead in Uruguayan children: Individual- vs neighborhood-level ensemble learners.

Predicting childhood blood lead levels (BLLs) has had mixed success, and it is unclear if individual- or neighborhood-level variables are most predictive. An ensemble machine learning (ML) approach to identify the most relevant predictors of BLL ≥2μg/dL in urban children was implemented. A cross-sectional sample of 603 children (~7 years of age) recruited between 2009-2019 from Montevideo, Uruguay participated in the study. 77 individual- and 32 neighborhood-level variables were used to predict BLLs ≥2μg/dL. Three ensemble learners were created: one with individual-level predictors (Ensemble-I), one with neighborhood-level predictors (Ensemble-N), and one with both (Ensemble-All). Each ensemble learner comprised four base classifiers with 50% training, 25% validation, and 25% test datasets. Predictive performance of the three ensemble models was compared using area under the curve (AUC) for the receiver operating characteristic (ROC), precision, sensitivity, and specificity on the test dataset. Ensemble-I (AUC: 0.75, precision: 0.56, sensitivity: 0.79, specificity: 0.65) performed similarly to Ensemble-All (AUC: 0.75, precision: 0.63, sensitivity: 0.79, specificity: 0.69). Ensemble-N (AUC: 0.51, precision: 0.0, sensitivity: 0.0, specificity: 0.50) severely underperformed. Year of enrollment was most important in Ensemble-I and Ensemble-All, followed by household water Pb. Three neighborhood-level variables were among the top 10 important predictors in Ensemble-All (density of bus routes, dwellings with stream/other water source and distance to nearest river). The individual-level only model performed best, although precision was improved when both neighborhood and individual-level variables were included. Future predictive models of lead exposure should consider proximal predictors (i.e., household characteristics).

Spatial Variability in Relationships between Early Childhood Lead Exposure and Standardized Test Scores in Fourth Grade North Carolina Public School Students (2013-2016).

Exposure to lead during childhood is detrimental to children's health. The extent to which the association between lead exposure and elementary school academic outcomes varies across geography is not known. Estimate associations between blood lead levels (BLLs) and fourth grade standardized test scores in reading and mathematics in North Carolina using models that allow associations between BLL and test scores to vary spatially across communities. We link geocoded, individual-level, standardized test score data for North Carolina public school students in fourth grade (2013-2016) with detailed birth records and blood lead testing data retrieved from the North Carolina childhood blood lead state registry on samples typically collected at 1-6 y of age. BLLs were categorized as: (reference), , and . We then fit spatially varying coefficient models that incorporate information sharing (smoothness), across neighboring communities via a Gaussian Markov random field to provide a global estimate of the association between BLL and test scores, as well as census tract-specific estimates (i.e., spatial coefficients). Models adjusted for maternal- and child-level covariates and were fit separately for reading and math. The average BLL across the 91,706 individuals in the analysis dataset was . Individuals were distributed across 2,002 (out of 2,195) census tracts in North Carolina. In models adjusting for child sex, birth weight percentile for gestational age, and Medicaid participation as well as maternal race/ethnicity, educational attainment, marital status, and tobacco use, BLLs of , and were associated with overall lower reading test scores of [95% confidence interval (CI): , ], (, ), and (, ), respectively. For BLLs of , , and , spatial coefficients-that is, tract-specific adjustments in reading test score relative to the "global" coefficient-ranged from to 2.52, to 3.90, to 7.85, and to 4.33, respectively. Results for mathematics were similar to those for reading. The association between lead exposure and reading and mathematics test scores exhibits considerable heterogeneity across North Carolina communities. These results emphasize the need for prevention and mitigation efforts with respect to lead exposures everywhere, with special attention to locations where the cognitive impact is elevated. https://doi.org/10.1289/EHP13898.

BLOOD LEAD CONCENTRATION ANALYSIS BETWEEN REHABILITATION FACILITY AND PERI-URBAN ENVIRONMENT VIRGINIA OPOSSUMS (DIDELPHIS VIRGINIANA) OF ILLINOIS.

The Virginia opossum (Didelphis virginiana) is the only marsupial in North America with a natural range north of Mexico. Its range is widespread throughout the United States, including Illinois. Virginia opossums are opportunistic omnivores that will eat a variety of fruits, grains, insects, and even carrion. They are a ground-foraging species, with frequent soil contact allowing for potential exposure to heavy metal contaminants in terrestrial environments. They are also opportunists that thrive in human-altered ecosystems, including peri-urban environments. Lead is a naturally occurring element and highly toxic metal that is abundant in the soil, primarily due to anthropogenic factors such as fossil fuel use, paint, industrial production waste, and battery recycling. Furthermore, carrion and offal piles containing lead bullet fragments remaining from hunting result in environmental contamination of this heavy metal. Few studies exist on lead exposure in the Virginia opossum. This pilot study evaluates the blood lead burden of 16 free-ranging Virginia opossums presented to a wildlife rehabilitation facility, compared with 16 wild-caught Virginia opossums trapped in grassland, maintained forest, or mixed ecotones. In other species, lead toxicosis has been associated with cognitive dysfunction that may increase the likelihood of trauma or injury in a free-ranging setting. In addition, a high incidence of Virginia opossums presenting for wildlife rehabilitation do so as result of human-animal conflict. Therefore, it was anticipated that individuals presenting for wildlife rehabilitation would have significantly higher blood lead concentrations than their free-roaming counterparts. In this study, every Virginia opossum had measurable blood lead concentrations and the average blood lead concentration of the rehabilitated group was 2.7 times higher than that measured in wild-caught Virginia opossums. These results suggest that Virginia opossums are exposed and susceptible to lead toxicosis due to their diet and foraging behaviors, making them more prone to subsequent injury and presentation to wildlife rehabilitation centers.

Commentary on: Lead exposure by E-waste disposal and recycling in Agbogbloshie, Ghana by Püschel et al. International Journal of Hygiene and Environmental Health 259 (2024)

Commentary on: Lead exposure by E-waste disposal and recycling in Agbogbloshie, Ghana by Püschel et al. International Journal of Hygiene and Environmental Health 259 (2024)

Abstract P129: Assessing the impact of serum lead levels on kidney function Among hypertensive population: NHANES 2017-2020

Purpose: Hypertension and chronic kidney disease is known adverse effects of lead poisoning. However, there is limited evidence on the magnitude of the relationship between blood lead levels and kidney function, especially on a national scale. This study investigates the association of serum lead levels (Pb-S) with estimated glomerular filtration rate (eGFR). Method: A national study of 6,789 adults, using NHANES 2017-2020 data, analyzed the correlation between Pb-S and eGFR. Participants were categorized into non-hypertension and hypertension groups based on self-reported for doctor diagnosis, with three linear regression models employed. Results: In our population, 35.6% have been diagnosed with hypertension, with 36.1% in males and 35.2% in females. The average SBP and DBP were 130.7 ± 17.8 mmHg and 77.6 ± 12.7 mmHg, respectively. The average Pb-S level was 1.04 ± 0.68 µg/dL, with 1.16 ± 0.72 µg/dL for males and 0.94 ± 0.63 µg/dL for females (mean difference 0.22 ± 0.02, P&lt;0.001). Individuals with hypertension had higher mean Pb-S levels compared to those without hypertension (1.15 ± 0.70 vs. 0.98 ± 0.66 µg/dL; mean difference 0.17 ± 0.02, P&lt;0.001). In the final adjusted model, eGFR declined by -1.28 (95% CI: -2.16 to -0.39) in the total group, by -0.35 (95% CI: -1.50 to 0.80) in the non-hypertension group, and by -2.50 (95% CI: -3.90 to -1.11) in the hypertension group, respectively (Fig 1). Conclusion: The Pb-S is inversely associated with kidney function in adult hypertensive population in the United States Testing for Pb-S may be considered to especially in hypertensive patients with declined kidney function who are at risk for lead exposure or toxicity.

Influences of quality of maternal care and environmental enrichment on associative memory function in rats with early life lead exposure.

Children in low socioeconomic status (SES) communities are at higher risk of exposure to lead (Pb) and potentially more severe adverse outcomes from Pb exposures. While the factors encompassing SES are complex, low SES households often have less enriching home environments and parent-child interactions. This study investigated the extent to which environmental/behavioral factors (quality of maternal care and richness of the postnatal environment) may modify adverse effects from Pb exposure. Long-Evans female rats were randomly assigned to Control (no Pb), Early Postnatal (EPN: birth through weaning), or Perinatal (PERI: 14 days pre-mating through weaning) Pb exposure groups. From postnatal days (PNDs) 2-9, maternal care behaviors were observed, and dams were classified as low or high maternal care based on amounts of licking/grooming and arched back nursing. At weaning, pups were randomly assigned to enriched or non-enriched environments. At PND 55, animals began trace fear conditioning and associative memory was tested on days 1, 2, and 10 postconditioning. Control offspring showed no significant effects of maternal care or enrichment on task performance. Females with EPN-Pb exposure and males with PERI-Pb exposure living in the non-enriched environment and having an LMC mother had significant memory impairments at days 2 and 10 that were not observed in comparably housed animals with HMC mothers. Enriched animals had no deficits, regardless of maternal care status. These results show the potential for modulatory influences of maternal care and housing environment on protecting against or reversing at least one aspect of Pb-induced cognitive/behavioral dysfunction.

A randomized controlled trial of a housing intervention to reduce endocrine disrupting chemical exposures in children

Few studies have considered household interventions for reducing endocrine disrupting chemical (EDC) exposures. We conducted a secondary analysis of a randomized controlled trial, originally designed to reduce lead exposure, to evaluate if the intervention lowered EDC exposures in young children. Study participants were children from the Cincinnati, Ohio area (n = 250, HOME Study). Prenatally, families received a housing intervention that included paint stabilization and dust mitigation, or as a control, injury prevention measures. At 24-months, we measured organophosphate esters (OPEs) and phthalates or their metabolites in dust and urine. We measured perfluoroalkyl substances (PFAS) in dust and serum at 24- and 36-months, respectively. We assessed associations between dust and biomarker EDCs using Spearman correlations, characterized EDC mixtures via principal components analysis, and investigated treatment effects using linear regression. To mitigate selection bias, we fit statistical models using inverse probability of retention weights. Correlations between dust EDCs and analogous biomarkers were weak-to-moderate (ρ’s ≤ 0.3). The intervention was associated with 23 % (95 % CI: −38, −3) lower urinary DEHP metabolites and, in a per-protocol analysis, 34 % lower (95 % CI: −55, −2) urinary MBZP. Additionally, among Black or African American children, the intervention was associated with lower serum concentrations of several PFAS (e.g., −42 %; 95 % CI: −63, −8 for PFNA). Household interventions that include paint stabilization and dust mitigation may reduce childhood exposures to some phthalates and PFAS in Blacks/African Americans. These findings highlight the need for larger studies with tailored and sustained housing interventions.