Current situation of lead (Pb) exposure in raptors and waterfowl in Japan and difference in sensitivity to in vitro lead exposure among avian species

Although lead (Pb) poisoning in wild birds has been considered a serious problem in Japan for over 30 years, there is little information about Pb exposure and its sources throughout Japan except for Hokkaido. Furthermore, to identify and effectively prioritize the conservation needs of highly vulnerable species, differences in sensitivity to Pb exposure among avian species need to be determined. Therefore, we investigated the current situation of Pb exposure in raptors (13 species, N = 82), waterfowl (eight species, N = 44) and crows (one species, N = 6) using concentration and isotope analysis. We employed blood or tissue samples collected in various Japanese facilities mainly in 2022 or 2023. We also carried out a comparative study of blood δ-ALAD sensitivity to in vitro Pb exposure using blood of nine avian species. Pb concentrations in the blood or tissues displayed increased levels (>0.1 μg/g blood) in two raptors (2.4%), ten waterfowl (23%) and one crow (17%). Among them, poisoning levels (>0.6 μg/g blood) were found in one black kite and one common teal. The sources of Pb isotope ratios in ten blood samples with high Pb levels were determined as deriving from shot pellets (N = 9) or rifle bullets (N = 1). In the δ-ALAD study, red-crowned crane showed the highest sensitivity among the nine tested avian species and was followed in order by five Accipitriformes species (including white-tailed and Steller's sea eagle), Blakiston's fish owl, Muscovy duck and chicken, suggesting a genetically driven variance in susceptibility. Further studies on contamination conditions and exposure sources are urgently needed to inform strict regulations on the usage of Pb ammunition. Furthermore, detailed examinations of δ-ALAD sensitivity, interspecific differences, and other factors involved in the variability in sensitivity to Pb are required to identify and prioritize highly sensitive species.

Blood lead levels and math learning in first year of school: An association for concern

Lead is a well-known neurotoxicant that continues to affect children's cognition and behavior. With the aim to examine the associations of lead exposure with math performance in children at the beginning of formal schooling, we conducted a cross-sectional study of first-grade students from 11 schools in Montevideo, Uruguay. Math abilities were assessed with tests from the Batería III Woodcock-Muñoz (Calculation, Math Facts Fluency, Applied Problems, Math Calculation Skills and Broad Maths). Separate generalized linear models (GLM) tested the association of blood lead level (BLL) and each math ability, adjusting for key covariates including age and sex, maternal education, household assets and Home Observation for Measurement of the Environment Inventory score. In a complete-case of 252 first-grade students (age 67-105 months, 45% girls), mean ± SD blood lead level was 4.0 ± 2.2 μg/dL. Covariate-adjusted logistic models were used to examine the association between childhood BLLs and the odds of low math performance. BLL was negatively associated with scores on the Calculation test (β (95% CI): -0.18 (-0.33, -0.03)), Math Calculation Skills (-1.26 (-2.26, -0.25)), and Broad Maths cluster scores (-0.88 (-1.55, -0.21)). Similarly, performance on the Calculation test, as well as cluster scores for Broad Maths and Math Calculation Skills differed between children with BLLs <5 and ≥ 5 μg/dL (p < 0.01), being lower in children with higher BLLs. Finally, considering the likelihood of low test performance, each 1 μg/dL higher B-Pb was related to 27% higher likelihood for Maths Facts Fluency, 30% for Broad Math and Math Calculation Skills, and 31% for Calculation (p < 0.05). These results suggest that lead exposure is negatively associated with several basic skills that are key to math learning. These findings further suggest that the cognitive deficits related to lead exposure impact student achievement at very early stages of formal education.

Lead exposure, glucocorticoids, and physiological stress across the life course: A systematic review

The biological pathways linking lead exposure to adverse outcomes are beginning to be understood. Rodent models suggest lead exposure induces dysfunction within the hypothalamic-pituitary-adrenal (HPA) axis and glucocorticoid regulation, a primary physiological stress response system. Over time, HPA axis and glucocorticoid dysfunction has been associated with adverse neurocognitive and cardiometabolic health, much like lead exposure. This systematic review utilized PRISMA guidelines to synthesize the literature regarding associations between lead exposure and downstream effector hormones of the HPA axis, including cortisol, a glucocorticoid, and dehydroepiandrosterone (DHEA), a glucocorticoid antagonist. We additionally determined the state of the evidence regarding lead exposure and allostatic load, a measure of cumulative body burden resultant of HPA axis and glucocorticoid dysfunction. A total of 18 articles were included in the review: 16 assessed cortisol or DHEA and 3 assessed allostatic load. Generally, the few available child studies suggest a significant association between early life lead exposure and altered cortisol, potentially suggesting the impact of developmental exposure. In adulthood, only cross sectional studies were available. These reported significant associations between lead and reduced cortisol awakening response and increased cortisol reactivity, but few associations with fasting serum cortisol. Two studies reported significant associations between increasing lead exposure and allostatic load in adults and another between early life lead exposure and adolescent allostatic load. The paucity of studies examining associations between lead exposure and allostatic load or DHEA and overall heterogeneity of allostatic load measurements limit conclusions. However, these findings cautiously suggest associations between lead and dysregulation of physiological stress pathways (i.e., glucocorticoids) as seen through cortisol measurement in children and adults. Future research would help to elucidate these associations and could further examine the physiological stress pathway as a mediator between lead exposure and detrimental health outcomes.

Prenatal and childhood lead exposure is prospectively associated with biological markers of aging in adolescence

Few studies have related early life lead exposure to adolescent biological aging, a period characterized by marked increases in maturational tempo. We examined associations between prenatal and childhood lead exposure and adolescent biological age (mean 14.5 years) utilizing multiple epigenetic clocks including: intrinsic (IEAA), extrinsic (EEAA), Horvath, Hannum, PhenoAge, GrimAge, Skin-Blood, Wu, PedBE, as well as DNA methylation derived telomere length (DNAmTL). Epigenetic clocks and DNAmTL were calculated via adolescent blood DNA methylation measured by Infinium MethylationEPIC BeadChips. We constructed general linear models (GLMs) with individual lead measures predicting biological age. We additionally examined sex-stratified models and lead by sex interactions, adjusting for adolescent age and lead levels, maternal smoking and education, and proportion of cell types. We also estimated effects of lead exposure on biological age using generalized estimating equations (GEE). First trimester blood lead was positively associated with a 0.14 increase in EEAA age in the GLMs though not the GEE models (95%CI 0.03, 0.25). First and 2nd trimester blood lead levels were associated with a 0.02 year increase in PedBE age in GLM and GEE models (1st trimester, 95%CI 0.004, 0.03; 2nd trimester, 95%CI 0.01, 0.03). Third trimester and 24 month blood lead levels were associated with a -0.06 and -0.05 decrease in Skin-Blood age, respectively, in GLM models. Additionally, 3rd trimester blood lead levels were associated with a 0.08 year decrease in Hannum age in GLM and GEE models (95%CI -0.15, -0.01). There were multiple significant results in sex-stratified models and significant lead by sex interactions, where males experienced accelerated biological age, compared to females who saw a decelerated biological age, with respect to IEAA, EEAA, Horvath, Hannum, and PedBE clocks. Further research is needed to understand sex-specific relationships between lead exposure and measures of biological aging in adolescence and the trajectory of biological aging into young adulthood.

Peiminine alleviate coliti-like phenotype in mice induced by lead exposure

The deleterious impact of lead (Pb) pollution on human health is evident in both domestic and occupational settings, provoking an inflammatory response across multiple tissue, limited attention has been devoted to its adverse effects on colitis and the underlying mechanisms. Peiminine (PMI) has been recognized for its anti-inflammatory properties, yet its specific anti-inflammatory effects in lead-induced colitis models remain elusive. Through the establishment of both in vivo and in vitro lead exposure models, suggests that lead exposure can induce colitis and that PMI regulates lead exposure-induced colitis by inhibiting the NF-kB signaling pathway, and alleviates the ability of lead to apoptosis and inflammation levels in intestinal epithelial cells. Consequently, these results present a promising avenue for further exploration of the molecular mechanisms underlying lead-induced colitis, evaluation of the associated risks linked to lead exposure, and the development of therapeutic interventions for colitis resulting from lead exposure.

Cottage industry as a source of high exposure to lead: A biomonitoring study among people involved in manufacturing cookware from scrap metal

In low-income countries, a widespread but poorly studied type of cottage industry consists of melting scrap metal for making cookware. We assessed the exposure to lead (Pb) among artisanal workers, and their families, involved in manufacturing cookware from scrap metal. In a cross-sectional survey, we compared artisanal cookware manufacturing foundries with carpentry workshops (negative controls) and car battery repair workshops (positive controls), all located in residential areas, in Lubumbashi (DR Congo). We collected surface dust in the workspaces, and blood and urine samples among workers, as well as residents living in the cookware workshops. Trace elements were quantified in the samples by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). In surface dust, median Pb concentrations were higher in cookware foundries (347 mg/kg) than in carpentries (234 mg/kg) but lower than in battery repair workshops (22,000 mg/kg). In workers making the cookware (n = 24), geometric mean (GM) Pb blood cencentration was 118 μg/L [interquartile range (IQR) 78.4-204], i.e. nearly twice as high as among carpenters [60.2 μg/L (44.4-84.7), n = 33], and half the concentration of battery repair workers [255 μg/L (197-362), n = 23]. Resident children from the cookware foundries, had higher urinary Pb [6.2 μg/g creatinine (2.3-19.3), n = 6] than adults [2.3 (2.2-2.5), n = 3]. Our investigation confirms the high Pb hazard linked to car battery repair and reveals a high exposure to Pb among artisanal cookware manufacturers and their families, especially children, in residential areas of a city in a low-income country.

Reductions in spice lead levels in the republic of Georgia: 2020-2022

Spice adulteration using yellow lead chromate-based pigments has been documented as a growing global health concern. Spices from the Republic of Georgia with extremely high levels of lead, up to an order of magnitude higher than any other spices worldwide, have been implicated as sources of child lead poisoning. The objectives of this study were to 1) evaluate lead concentrations in spices sampled across the country of Georgia between 2020 and 2022, and 2) assess factors associated with spice adulteration, specifically the role of spice quality and regulatory enforcement. Spice samples were collected from 29 cities nationwide. The most populous cities were selected in each administrative region as well as those of importance to the spice supply chain. Sampling was carried out at the largest spice bazaars in each city. The regions of Adjara and Imereti were the focus of qualitative interviews conducted in 2021 with key businesspeople selling spices with very high and low levels of lead. The same cities and bazaars were visited at each of three sampling periods between 2020 and 2022. In total, 765 spice samples were collected. Lead concentrations in spices decreased over time, with a maximum of 14,233 μg/g in 2020 down to 36 μg/g in the final sampling round of 2022. A logistic regression determined that sampling round, region and spice type were associated with elevated lead in samples. Samples from Adjara and those containing marigold had the highest lead levels. Interviews with eighteen prominent spice vendors revealed difficulties sourcing sufficient quantities of high quality, brightly colored marigold, and concerns about adulteration. Interviews with two authorities from the National Food Authority highlighted the increased attention on regulating lead in spices since 2018. Continued monitoring and periodic regulatory enforcement may adequately disincentivize further adulteration with lead chromate in the spice industry in Georgia.

Integral trends in research of lead exposure and child health from 2012 to 2022: a bibliometric analysis

Lead poisoning in children is a non-negligible and ongoing threat to children's health and optimal development worldwide. There is no sufficient scientometric analysis available on this subject, though. Aiming to uncover the research development, hotspots, and possible future orientation, we performed a scientometric analysis of related publications from 2012 to 2022. Initial information was accessed using the "Analysis Results" and "Create Citation Report" sections of the Web of Science core collection database, which were utilized to find original publications in this field of research. Biblioshiny and VOSviewer software were applied to further analyze and visualize the data. The research addressed a range of topics, including yearly publications, highly cited articles, co-cited references, journals, authors, nations, organizations, and keywords. A total of 883 articles were retrieved. From 2018 to 2021, the annual publication output was abundant and peaked in 2019. Among 111 countries, the USA obtained the highest number of documents issued, total citations, and total link strength. Meanwhile, most of the top 15 institutions, including the top four, are located in the USA. Further, we spotted greater scopes with development potential, including enhancing records to lessen exposure to harmful risks, improving methods for observing lead sources, and elucidating the gradient link between lead poisoning symptoms and concentrations. We anticipate that our research will assist researchers in summarizing previous research and providing perspectives for workable prospective study topics.

A systematic analysis of chronic kidney disease burden attributable to lead exposure based on the global burden of disease study 2019

AIM

As an important toxic heavy metal, lead exposure can lead to the occurrence of chronic kidney disease (CKD). However, the analysis of its disease burden pattern on a global scale is lacking. This study aimed to analyze the CKD burden attributable to lead exposure globally, regionally and temporally, as well as to examine the role of socio-economic factors.

METHOD

This study used data from the Global Burden of Disease (GBD) study 2019. We obtained the global burden of CKD caused by lead exposure between 1990 and 2019, and stratified this burden according to factors such as gender, age, GBD regions, and countries. From 1990 to 2019, the changing trend of the disease burden of CKD attributed to lead exposure was estimated using Joinpoint regression model with the average annual percent change (AAPC) estimated. Finally, the relationship between country-level socio-economic factors and lead exposure related CKD burden was explored using a panel data model analysis.

RESULTS

In 2019, worldwide, there were 52.94 thousand deaths (95 % uncertainty interval (UI): 31.64, 76.23) and 1225.2 thousand disability-adjusted life years (DALYs) (95 % UI: 707.88, 1818) of CKD caused by lead exposure, accounting for 3.71 % of total CKD deaths and 2.95 % of total CKD DALYs. The age-standardized death and DALY rates per 100,000 population were 0.68 (95 % UI: 0.40, 0.98) and 15.02 (95 % UI: 8.68, 22.26) respectively, indicating an upward trend and stable trend between 1990 and 2019. However, the age-standardized rates attributed to lead exposure showed a wide variability across regions, with the highest rates in Central Latin America and the lowest in Eastern Europe. Moreover, the results of panel model analysis indicated that GDP growth was positively associated with lead exposure related CKD death rate and DALY rate. However, there were inverse associations between life expectancy at birth and hospital beds (per 1000 people) with lead exposure-related CKD DALY rate.

CONCLUSION

In summary, a significant burden of CKD can be attributed to lead exposure, with noticeable regional discrepancies. Findings here are valuable to deploy efficient measures at curbing lead exposure worldwide.

Blood Homocysteine Levels Mediate the Association Between Blood Lead Levels and Cardiovascular Mortality

Lead is a heavy, toxic metal and its exposure to humans can lead to increased risk of cardiovascular disease development and mortality. Lead exposure has been shown to induce hyperhomocysteinemia (HHCy) which may be a major pathogenic risk for the risk of CVDs. The aim of this study was to investigate whether homocysteine (Hcy) mediates the effect of lead on cardiovascular mortality. A total of 17,915 adults aged ≥ 20 who participated in the National Health and Nutrition Examination Survey (1999 to 2006). Information on mortality was ascertained via probabilistic matching to the death certificates from the National Death Index recorded up to December 31, 2015. Cox proportional hazards regression was performed to assess the association between blood lead levels and mortality. Mediation via Hcy was examined using a logit model. During a mean follow-up of 11.6 years, the incidences of CVD mortality were 0.73, 2.18, 3.03 and 4.94 per 1000 person-years across quarterlies of blood lead levels from low to high. Following multivariable adjustment, blood lead levels were strongly associated with CVD mortality in all mortality models (p-trend < 0.001). This association remained statistically significant after further adjusting for quartiles of homocysteine (model 3; HR 1.38 (95% CI 1.01-1.89) p-trend < 0.001). Furthermore, blood lead levels increased the odds of CVD mortality via homocysteine (indirect effect) (OR 1.42 (95% CI 1.30-1.55)), demonstrating the mediatory effect of homocysteine. This the first study that demonstrates that increased homocysteine mediates nearly half of CVD mortality related to blood lead levels.

Enduring Ethanol-Induced Behavioral Alterations in Caenorhabditis elegans After Developmental Lead Exposure

The roundworm Caenorhabditis elegans (C. elegans) has become a powerful tool to evaluate the deleterious effects of early-life exposure to xenobiotics, including metals. The present chapter describes a detailed protocol for developmental lead (Pb)-exposure in C. elegans. Preliminary assays as well as the final procedure are described in detail. In addition, further protocols aimed to assess ethanol exposure at later stages of life demonstrate the impact of this drug on locomotor behavior, revealing the enduring effects that Pb can imprint on this organism when exposure occurs during development.

Lead activates neutrophil degranulation to induce early myocardial injury in mice

Lead (Pb) is a pervasive toxic metal contaminant associated with a high risk of myocardial injury. However, the precise mechanism underlying Pb-induced myocardial injury has yet to be fully elucidated. In this study, a murine model of Pb exposure (0, 1, 5, and 10 mg/kg) was employed to investigate the involvement of neutrophil degranulation in the induction of myocardial injury. Notably, serum levels of cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) increased significantly in Pb-exposed mice, whereas cTnI levels in cardiomyocytes decreased, suggesting that Pb exposure may cause early myocardial injury. Moreover, Pb exposure was found to promote neutrophil degranulation, as evidenced by elevated myeloperoxidase (MPO) and neutrophil elastase (NE) concentrations in both the serum of Pb-exposed workers and Pb-exposed mice, as well as the extracellular supernatant of neutrophils following exposure. However, we found that serum level of cTnI enhanced by Pb exposure is associated with increased NE levels in the serum, but not with MPO levels. Upon treatment with NE inhibitor (sivelestat), the serum level of cTnI markedly reduced in Pb-exposed mice, we found that early myocardial injury is associated with NE levels in the serum. At the molecular level, western blotting analysis revealed an upregulation of ERK1/2 expression in vitro following Pb exposure, suggesting that the activation of the ERK1/2 signaling pathway may underlie the participation of neutrophil degranulation in Pb-induced myocardial injury. In summary, our findings demonstrate that Pb exposure can initiate early myocardial injury by promoting the neutrophil degranulation process, thereby highlighting the potential role of this process in the pathogenesis of Pb-associated myocardial injury.

Disease burden of chronic kidney disease attributable to lead exposure: A global analysis of 30 years since 1990

BACKGROUND

Exposure to lead (Pb) is associated with an increased risk of chronic kidney disease (CKD). However, limited studies explored the global burden of CKD attributable to Pb exposure, especially in countries with different development levels. This study aimed to comprehensively evaluate the temporal and spatial trend in the disease burden of CKD attributable to Pb exposure in 204 countries and territories from 1990 to 2019.

METHODS

We used the data from Global Burden of Disease Study (GBD) 2019 to estimate annual deaths, disability-adjusted life years (DALYs), age-standardized mortality rates (ASMR), and age-standardized DALYs rate (ASDR) of CKD attributable to Pb exposure. The annual average percentage change (AAPCs) was calculated using the Joinpoint model to evaluate the changing trend of CKD ASMR and ASDR attributable to Pb exposure from 1990 to 2019. Meanwhile, age-period-cohort (APC) model was used to assess changes in the mortality of CKD attributable to Pb exposure from 1990 to 2019.

RESULTS

Global ASMR for CKD attributable to Pb exposure trended upward from 1990 to 2019. ASMR and ASDR were the highest in low and low-middle SDI regions. With the APC model, we found that global mortality rates for CKD attributable to Pb exposure increased with age. The global period rate ratio showed the highest value in 2000-2004 and the lowest in 2015-2019, while the global cohort rate ratio showed the highest value in 1941-1949 and the lowest during 1986-1994.

CONCLUSIONS

From 1990 to 2019, the global burden of CKD attributable to Pb exposure increased globally, especially in low and low-middle SDI regions, as well as the elderly. Pb exposure is still a great threat to the global burden of CKD, and the implementation of effective prevention measures to reduce Pb exposure in the environment should be continually strengthened.

Succimer chelation does not produce lasting reductions of blood lead levels in a rodent model of retained lead fragments

Retained lead fragments from nonfatal firearm injuries pose a risk of lead poisoning. While chelation is well-established as a lead poisoning treatment, it remains unclear whether chelation mobilizes lead from embedded lead fragments. Here, we tested whether 1) DMSA/succimer or CaNa2EDTA increases mobilization of lead from fragments in vitro, and 2) succimer is efficacious in chelating fragment lead in vivo, using stable lead isotope tracer methods in a rodent model of embedded fragments. DMSA was > 10-times more effective than CaNa2EDTA in mobilizing fragment lead in vitro. In the rodent model, succimer chelation on day 1 produced the greatest blood lead reductions, and fragment lead was not mobilized into blood. However, with continued chelation and over 3-weeks post-chelation, blood lead levels rebounded with mobilization of lead from the fragments. These findings suggest prolonged chelation will increase fragment lead mobilization post-chelation, supporting the need for long-term surveillance in patients with retained fragments.

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.

Emerging roles of epigenetics in lead-induced neurotoxicity

Lead is a common environmental heavy metal contaminant. Humans are highly susceptible to lead accumulation in the body, which causes nervous system damage and leads to a variety of nervous system diseases, such as Alzheimer's disease, Parkinson's disease, and autism spectrum disorder. Recent research has focused on the mechanisms of lead-induced neurotoxicity at multiple levels, including DNA methylation, histone modifications, and non-coding RNAs, which are involved in various lead-induced nervous system diseases. We reviewed the latest articles and summarised the emerging roles of DNA methylation, histone modification, and non-coding RNAs in lead-induced neurotoxicity. Our summary provides a theoretical basis and directions for future research on the prevention, diagnosis, and treatment of lead-induced neurological diseases.

Lead Exposure of Four Biologically Important Common Branded and Non-branded Spices: Relative Analysis and Health Implication

Technological advances and socioeconomic development of Bangladesh are leading to the best choice between branded and non-branded powdered spices. But toxic metal issues can be another factor to elect them. So lead (Pb) exposure and its consequence on the human body for these two categories of four common spices have been ascertained here. A validated laboratory method using hot plate digestion and flame atomic absorption spectrometry (FAAS) has been used for that. The obtained mean concentration of Pb in branded and non-branded spice powders followed the decreasing order of turmeric > coriander > red chili > cumin powder and turmeric > red chili > cumin > coriander powder, respectively, where, in any analysis mode, the non-branded items are potentially ahead of Pb exposure. The market-based mean concentration between these two categories was not a significant difference (t-test). Approximately 90% of the spice samples have shown within the maximum allowable limit by Bangladesh Standard. The sum of estimated daily intake indicated that most of the city market (67%) for non-branded items and some branded (33%) samples have crossed the maximum tolerable daily intake (> 0.21 mg/kg). So, the human health risk assumption for the inhabitant of studied areas suggests there is no significant level of risk for them due to the consumption of spices regarding non-carcinogenic risk factor (THQ and total THQ) and carcinogenic risk factor (CR). But the development of a quality control process for loose spice powders as well as toxic metal screening from raw materials to finish products urgently needed and continuous monitoring with identifying the source of toxic metal is highly recommended.

The Relationship between Blood Lead Level and Chronic Pain in US Adults: A Nationwide Cross-Sectional Study

INTRODUCTION

Lead toxicity has been a major public health problem worldwide, yet no study has investigated the association between lead exposure and chronic pain.

METHODS

We used data from three cycles of National Health and Nutrition Examination Survey (NHANES) with chronic pain status. We conducted univariate and multivariate logistic regression analyses to investigate the association between chronic pain and blood lead level (BLL). Subgroup analyses were performed to explore which confounding factor modified the association between chronic pain and BLL.

RESULTS

A total of 13,485 participants were included in our final analysis, out of which 1950 (14.46%) had chronic pain. In the fully adjusted model, a 1 μg/dL increase of BLL was associated with 3% higher risk of chronic pain. The highest BLL quartile (BLL > 2.40 μg/dL) was associated with a 32% increase in the risk of chronic pain compared with the lowest BLL quartile (BLL < 0.90 μg/dL). In the subgroup analyses, hypertension (P for interaction = 0.018) and arthritis (P for interaction = 0.004) status modified the association between BLL and chronic pain. Higher quartiles of BLL were associated with a higher risk of chronic pain only in individuals with hypertension or arthritis but not those without these conditions.

CONCLUSION

A higher BLL was associated with a higher risk of chronic pain. Further research is warranted to investigate whether a causal relationship exists between the two, as well as potential underlying mechanisms.

Association Between Blood Lead Levels and Thyroid Function: An Updated Systematic Review and Meta-Analysis

Chronic Lead (Pb) exposure is associated with disrupting certain endocrine levels and is referred to as an endocrine disruptor. Thyroid hormones, involved in regulating numerous physiological functions, are reported with conflicting associations with chronic Pb exposure. This study broadly evaluated the association between long-term lead exposure and thyroid function parameters. In this systematic review, the observational studies documenting the changes in thyroid function parameters between the chronically Pb-exposed and controls were systematically identified from PubMed-Medline, Scopus, and Embase digital databases from the beginning to March 31, 2022. The protocol was previously registered with PROSPERO (ID: CRD42022315520) and executed following PRISMA 2020 guidelines. The random-effects model was used to analyze the mean differences in thyroid function parameters between groups. The classical I2 statistic was applied to assess heterogeneity, while the Newcastle Ottawa Scale was used to assess the risk of various biases. Where data allowed, sub-group, sensitivity, and meta-regression analyses were carried out. The current systematic review included fifteen observational studies. The Pb-exposed have a higher mean blood Pb level [i.e. 28.07 (95% CI 21.43-34.72) µg/dl], significantly higher free T3 [(i.e. 0.48 pg/dl (95% CI 0.05-0.95)] and trend of higher T3. T4, FT4, and TSH levels than controls with high heterogeneity (I2 > 85%). Considering the important role of thyroid hormone in multiple biological functions, the present findings emphasize the requisite for high-quality studies to investigate the association between levels of thyroid function parameters among individuals known for cumulative exposure to Pb.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-023-01113-8.

Health risk assessment of lead via the ingestion pathway for preschool children in a typical heavy metal polluted area

The problems of environmental lead (Pb) pollution caused by mining activities have attracted global attention. Preschool children are vulnerable to exposure to Pb from the environment. To investigate the health risk of multiple exposures to Pb via oral ingestion (soil, water, rice, wheat, and vegetables) for preschool children in typical polluted areas, in this study, preschool children in Baiyin city were selected as the potential receptors, Pb concentrations in 28 soil samples and 33 vegetable samples were collected and measured. In addition, the Pb concentrations in local water, rice, and wheat were obtained by searching the literature. The Monte Carlo simulation was used in the uncertainty and sensitivity analysis of the parameters. Results showed that Pb concentrations in spinach, tomato, cushaw, lettuce, broad bean, pea, eggplant, and radish exceeded the standards (GB 2762-2017), and 42.86% of soil samples exceeded screening values (GB 15618-2018). The non-carcinogenic risk was as high as 3.58. Vegetables and wheat were the major contributors in the oral ingestion pathway. Furthermore, the carcinogenic risk of preschool children was 6.02E-06, which was acceptable. Monte Carlo simulations showed that health risk assessment results were most likely to be influenced by Pb concentrations in the media. In conclusion, the food safety of vegetables in soil-polluted areas deserves more attention, and certain measures should be taken to reduce the health risks to preschool children.

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

BACKGROUND

Lead is a major developmental neurotoxicant in children, and tobacco smoke has been suggested as a source of lead exposure in vulnerable populations. This study evaluates the contribution of secondhand tobacco smoke (SHS) to blood lead levels (BLLs) in children and adolescents.

METHODS

We analyze data from 2,815 participants aged 6-19 years who participated in the National Health and Nutrition Examination Survey (2015-2018) to investigate the association between serum cotinine levels and BLLs. A multivariate linear regression was conducted to estimate geometric means (GMs) and the ratios of GMs after adjusting for all covariates.

RESULTS

The geometric means of BLLs in study participants aged 6 - 19 years were 0.46 µg/dl (95% CI 0.44, 0.49). After adjusting for relevant participant characteristics, the geometric means of BLLs were 18% (BLL 0.48 µg/dl, 95% CI 0.45, 0.51) and 29% (BLL 0.52 µg/dl, 95% CI 0.46, 0.59) higher in participants who had intermediate serum cotinine levels (0.03 - 3 ng/mL) and those who had high serum cotinine levels (> 3 ng/mL) respectively, compared to participants who had low serum cotinine levels (BLL 0.41 µg/dl, 95% CI 0.38, 0.43).

CONCLUSIONS

SHS exposure may be a source of BLLs in US children and adolescents. Efforts to reduce lead exposure in children and adolescents should include strategies to reduce SHS exposure.

Patterns of global burden of 13 diseases attributable to lead exposure, 1990-2019

OBJECTIVES

Understanding the spatio-temporal patterns of the global burden of various diseases resulting from lead exposure is critical for controlling lead pollution and disease prevention.

METHODS

Based on the 2019 Global Burden of Disease (GBD) framework and methodology, the global, regional, and national burden of 13 level-three diseases attributable to lead exposure were analyzed by disease type, patient age and sex, and year of occurrence. Population attributable fraction (PAF), deaths and disability-adjusted life years (DALYs), age-standardized mortality rate (ASMR) and age-standardized DALYs rate (ASDR) obtained from the GBD 2019 database were used as descriptive indicators, and the average annual percentage change (AAPC) was estimated by a log-linear regression model to reflect the time trend.

RESULTS AND CONCLUSIONS

From 1990 to 2019, the number of deaths and DALYs resulting from lead exposure increased by 70.19% and 35.26%, respectively; however, the ASMR and ASDR decreased by 20.66% and 29.23%, respectively. Ischemic heart disease (IHD), stroke, and hypertensive heart disease (HHD) showed the highest increases in deaths; IHD, stroke, and diabetes and kidney disease (DKD) had the fastest-growing DALYs. The fastest decline in ASMR and ASDR was seen in stroke, with AAPCs of -1.25 (95% CI [95% confidence interval]: -1.36, -1.14) and -1.66 (95% CI: -1.76, -1.57), respectively. High PAFs occurred mainly in South Asia, East Asia, the Middle East, and North Africa. Age-specific PAFs of DKD resulting from lead exposure were positively correlated with age, whereas the opposite was true for mental disorders (MD), with the burden of lead-induced MD concentrated in children aged 0-6 years. The AAPCs of ASMR and ASDR showed a strong negative correlation with the socio-demographic index. Our findings showed that the global impact of lead exposure and its burden increased from 1990 to 2019 and varied significantly according to age, sex, region, and resulting disease. Effective public health measures and policies should be adopted to prevent and control lead exposure.

Food safety policy enforcement and associated actions reduce turmeric lead chromate adulteration across Bangladesh

Turmeric adulterated with lead chromate pigment has been previously identified as a primary source of lead exposure in Bangladesh. This study assesses the impact of a multi-faceted intervention between 2017 and 2021 to reduce lead-tainted turmeric in Bangladesh. The intervention involved: i) disseminating findings from scientific studies via news media that identified turmeric as a source of lead poisoning, ii) educating consumers and businesspeople about the risks of lead chromate in turmeric via public notices and face-to-face meetings, and iii) collaborating with the Bangladesh Food Safety Authority to utilize a rapid lead detection technology to enforce policy disallowing turmeric adulteration. Before and after the intervention, evidence of lead chromate turmeric adulteration was assessed at the nation's largest turmeric wholesale market and at turmeric polishing mills across the country. Blood lead levels of workers at two mills were also assessed. Forty-seven interviews were conducted with consumers, businesspeople, and government officials to assess changes in supply, demand, and regulatory capacity. The proportion of market turmeric samples containing detectable lead decreased from 47% pre-intervention in 2019 to 0% in 2021 (n = 631, p < 0.0001). The proportion of mills with direct evidence of lead chromate adulteration (pigment on-site) decreased from 30% pre-intervention in 2017 to 0% in 2021 (n = 33, p < 0.0001). Blood lead levels dropped a median of 30% (IQR: 21-43%), while the 90th percentile dropped 49% from 18.2 μg/dL to 9.2 μg/dL 16 months after the intervention (n = 15, p = 0.033). Media attention, credible information, rapid lead detection tools and swift government action to enforce penalties all contributed to the intervention's success. Subsequent efforts should evaluate if this is an example of an effective intervention that can be replicated to reduce lead chromate adulteration of spices globally.

High blood lead level correlates with selective hippocampal subfield atrophy and neuropsychological impairments

BACKGROUND

Lead contamination is a major public health concern. Previous studies have demonstrated that lead exposure could affect the hippocampus, which is a complex and heterogeneous structure composed of 12 subregions. Here, we explored volumetric and functional changes in hippocampal subfields and neuropsychological alterations after lead exposure.

METHODS

We performed a cross-sectional study at a smelting company between September 2020 and December 2021. Blood lead level was recorded, and neuropsychological functions were assessed by Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), Self-rating Anxiety Scale (SAS), and Self-rating Depression Scale (SDS). The hippocampus was segmented into 12 subfields in each hemisphere in magnetic resonance images (MRIs). Then, the effect of altered hippocampal subfield volumes on brain functions were studied by seed-based functional connectivity (FC) analysis. Finally, the relationships between the lead level with hippocampal subfield volumes and neuropsychological functions were investigated. Baseline characteristics, hippocampal subfield volumes, and FC analysis were compared between lead-exposed (≥ 300 μg/L) and the control group (≤ 100 μg/L).

RESULTS

In 76 participants, lead level positively correlated with SDS(r = 0.422) and negatively correlated with MoCA(r = -0.414), MMSE(r = -0.251), Concentration(r = -0.331), Recall(r = -0.319), Orientation(r = -0.298) and Executive Function/Visuospatial abilities(r = -0.231). Lead group (26 participants) had lower MoCA and MMSE and higher SDS than control group (23 participants). A significantly decreased volume in the left CA4 and GC-ML-DG subfields was found in the lead group compared with the control group. The left GC-ML-DG of the lead group showed a decreased FC with the bilateral postcentral gyrus. The left CA4(r = -0.409) and left GC-ML-DG (r = -0.383) volumes negatively correlated with lead level. The FC between left GC-ML-DG and left postcentral gyrus positively correlated with MoCA(r = 0.318), MMSE(r = 0.379) and Recall(r = 0.311). The FC between left GC-ML-DG and right postcentral gyrus positively correlated with MoCA(r = 0.326), Executive Function/Visuospatial abilities(r = 0.307) and Concentration(r = 0.297).

CONCLUSION

High blood lead level was associated with neuropsychological alterations, hippocampal structural and functional changes. The left GC-ML-DG and CA4 atrophy might serve as predictive imaging markers for neurological damage associated with high lead exposure.

Metals as toxicants in event-based expedited production of children's jewelry

Globally, the hazardous substance in children's goods is of great concern. Toxic chemicals are potentially harmful to the health and growth of infants and children. Lead (Pb) and cadmium (Cd)-contaminated children's jewelry is widely encountered in many countries. This study aims to determine the concentration of metal toxicants (Pb, Cd, Ni, Cu, Zn, Co, and Fe) in event-based (Independence Day festival) children's jewelry, considering time-limited and fast production products that may compromise the quality and safety parameters during manufacturing. The determinations are for the time-constraint industrial production of children's jewelry in the context of the toxic substances in a variety of base materials used. This is the first time event-based children's jewelry has been monitored and critically assessed for metal contamination. Forty-two samples, including metallic, wooden, textile, rubber, plastic, and paint-coated plastic children's jewelry, were tested. Seventy-four percent of samples detected Pb and Cd in quantifiable amounts. Ni in 71%, Cu in 67%, Co in 43%, and Zn and Fe were detected in 100% samples with quantifiable amounts. Twenty-two ID-CJ samples exceeded the US regulatory limit for Pb and four samples for Cd. However, twenty-nine samples for Pb, eleven for Cd, five for Co, and one for Cu exceeded the EU regulatory limit. The highest concentration of Pb was found in paint-coated plastic jewelry, and the highest Cd was found in metallic jewelry. These results suggest that the potential hazards of event-based children's jewelry deserve the attention of government agencies seeking to limit children's exposure to toxic chemicals. Intergovernmental organizations and individual countries regulate chemicals in consumer products, but a coordinated international approach is lacking. Some continents and countries still lack in regulations for children's products, especially jewelry, and toys.

The metabolism and detoxification effects of lead exposure on Aleurolyphus ovatus (Acari: Acaridae) via transcriptome analysis

Aleurolyphus ovatus Troupeau is one of the most predominant species of the Acaridae family worldwide. Recent reports have demonstrated that the accumulation of lead in stored grains and dietary items exceeds the required standards. However, the molecular mechanism of heavy metal stress on mites has not been reported. To understand the mechanism underlying the heavy metal response of A. ovatus, comparative transcriptome analysis was performed in this study using an Illumina high throughput mRNA sequencing (RNA-seq) platform. A. ovatus was fed on artificial diets containing two different concentrations of lead, namely, a low concentration of 12.5 mg/kg (LAO) and a high concentration of 100 mg/kg (HAO), while the mites in the control (NAO) group were not exposed to lead. A total of 44,362 unigenes, with an average length of 1547 bp, were identified. Of these, 996 unigenes were successfully annotated in seven functional databases. The number of differentially expressed genes (DEGs) in A. ovatus under different lead concentrations was compared. In NAO versus LAO group, including 310 up-regulated and 1580 down-regulated DEGs. In NAO versus HAO group, including 3928 up-regulated and 1761 down-regulated DEGs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment indicated that detoxification enzyme genes were significantly expressed in pathways, such as cytochrome P450 foreign body metabolism, glutathione metabolism and drug metabolism-cytochrome pathway. The results of gene annotation and quantitative real-time PCR showed that high concentration of lead significantly stimulated the expression of metabolic detoxification enzyme genes such as glutathione S transferase (GST) and superoxide dismutase (SOD), while low concentration inhibited their expression. This study will provide a basis for the molecular mechanism of A. ovatus in response to heavy metal lead stimulation in stored grain.

Associations Between the Lead Level in Maternal Blood and Umbilical Cord Blood and Congenital Heart Diseases in Offspring

The incidence of congenital heart diseases (CHDs) shows an increasing trend and results in large health burdens in China. However, there have been inconsistent results of the relationship between lead (Pb) level and risk of CHDs. We performed a pair-matched case-control study and included 97 cases and 194 controls to investigate the association between pregnancy Pb exposure and the risk of CHDs in a birth cohort study conducted in Lanzhou, China. The results showed that compared to the lowest Pb tertile, both highest tertile levels of maternal blood and umbilical cord blood Pb were associated with an increased risk of CHDs. The similar significant results were found in cases with isolated CHDs. Compared to both lowest tertiles of Pb level in maternal blood and umbilical cord blood, the highest tertile was associated with an increased risk of CHDs, especially for isolated CHDs. Overall, our study suggests a significant association between pregnancy Pb exposure and risk of CHDs, especially for isolated CHDs. Future studies are needed to elucidate the underlying mechanism.

Adaptive changes in redox response and decreased platelet aggregation in lead-exposed workers

Chronic lead exposure can generate pro-oxidative and pro-inflammatory conditions in the blood, related to high platelet activation and aggregation, altering cell functions. We studied ADP-stimulated aggregation and the oxidant/antioxidant system of platelets from chronically lead-exposed workers and non-exposed workers. Platelet aggregation was low in lead-exposed workers (62 vs. 97%), who had normal platelet counts and showed no clinical manifestations of hemostatic failure. ADP-activated platelets from lead-exposed workers failed to increase superoxide release (3.3 vs. 6.6 µmol/g protein), had low NADPH concentration (60 vs. 92 nmol/mg protein), high concentration of hydrogen peroxide (224 vs. 129 nmol/mg protein) and high plasma PGE₂ concentration (287 vs. 79 pg/mL). Altogether, those conditions, on the one hand, could account for the low platelet aggregation and, on the other, indicate an adaptive mechanism for the oxidative status of platelets and anti-aggregating molecules to prevent thrombotic problems in the pro-oxidant and pro-inflammatory environment of chronic lead exposure.

A better cost:benefit analysis yields better and fairer results: EPA's lead and copper rule revision

When conducted on a societal level, cost-benefit analysis (CBA) can indicate policies that best allocate scarce public resources. Done incompletely, CBA can produce spurious, biased results. To estimate the potential health benefits of EPA's recent Lead and Copper Drinking Water Rule Revision (LCRR), we used EPA's exposure, compliance, and effect coefficient estimates to monetize 16 of the health endpoints EPA has determined are causally related to lead exposure. In addition, we monetized one health endpoint that EPA has used elsewhere: preterm birth. We estimated that the total annual health benefits of the LCRR greatly exceed EPA's estimated annual costs: $9 billion vs $335 million (2016$). Our benefit estimates greatly exceed EPA's benefit estimates. There are also nonhealth benefits because lead generally contaminates drinking water through the corrosion of plumbing components that contain lead. The LCRR therefore has 2 components: reducing how corrosive the water is and limited replacement of lead pipes. Reducing corrosion damage to drinking water and wastewater infrastructure and residential appliances that use water yields significant annualized material benefits also: $2-8 billion (2016$). Effectively, the health benefits are free. Finally, while actual exposure data are limited, the available data on lead-contaminated drinking water exhibits known risk patterns, disproportionately burdening low-income and minority populations and women. This economic analysis demonstrates that to maximize national benefits and improve equity, the LCRR should be as rigorous as possible.

Soluble dietary fiber from Prunus persica dregs alleviates gut microbiota dysfunction through lead excretion

Lead (Pb) can pollute the environment and food through air, water and other means, resulting in human exposure to lead pollution, and there is no threshold level of lead toxicity, even small doses of lead will have a range of harmful effects in humans. This study demonstrates for the first time that dietary addition of soluble dietary fiber (SDF) from Prunus persica dregs reduces lead bioaccumulation in mice, and eliminates lead through feces. Compared with lead-exposed mice, SDF supplementation effectively prevented lead-induced changes in colon tissue, and increased expression of tight junction proteins (ZO-1 and occludin). We analyzed the effects of SDF on gut microbiota and metabolites by a combination of 16S rRNA high-throughput sequencing and untargeted metabolomics. The results showed that SDF altered lead-induced perturbations in the layout and structure of the gut microbiota, including increased Desulfovibrio and Alistipes abundance and decreased Bacteroidetes abundance. Meanwhile, we also provide evidence that SDF supplementation alters the levels of amino acids, bile acids, and lipids in the gut, and that these metabolites are closely associated with microbiota with good lead binding capacity. Therefore, we speculate that SDF has the potential to provide a protective effect against intestinal damage by promoting lead excretion.

Higher rates of autism and attention deficit/hyperactivity disorder in American children: Are food quality issues impacting epigenetic inheritance?

In the United States, schools offer special education services to children who are diagnosed with a learning or neurodevelopmental disorder and have difficulty meeting their learning goals. Pediatricians may play a key role in helping children access special education services. The number of children ages 6-21 in the United States receiving special education services increased 10.4% from 2006 to 2021. Children receiving special education services under the autism category increased 242% during the same period. The demand for special education services for children under the developmental delay and other health impaired categories increased by 184% and 83% respectively. Although student enrollment in American schools has remained stable since 2006, the percentage distribution of children receiving special education services nearly tripled for the autism category and quadrupled for the developmental delay category by 2021. Allowable heavy metal residues remain persistent in the American food supply due to food ingredient manufacturing processes. Numerous clinical trial data indicate heavy metal exposures and poor diet are the primary epigenetic factors responsible for the autism and attention deficit hyperactivity disorder epidemics. Dietary heavy metal exposures, especially inorganic mercury and lead may impact gene behavior across generations. In 2021, the United States Congress found heavy metal residues problematic in the American food supply but took no legislative action. Mandatory health warning labels on select foods may be the only way to reduce dietary heavy metal exposures and improve child learning across generations.

Domestic dogs as sentinels of children lead exposure: Multi-pathway identification and source apportionment based on isotope technique

Environmental lead exposure poses risks to children' health, thus exposure sources and pathways identification remain important concern and research scope. Due to sharing the same environment, domestic animals, especially dogs, have been used as useful sentinels to identify human lead exposure. However, more evidence is needed on whether domestic dogs could be used to identify the lead exposure pathways and sources of children. Thus, this study investigated the dietary habits, behaviors, and household environment of children and dogs in a typical coal-fired area in China. The lead levels and lead isotope ratios (Acronym: LIRs, expressed as ²⁰⁸Pb/²⁰⁶Pb and ²⁰⁷Pb/²⁰⁶Pb) in dogs' and children's blood, as well as in environmental media (food, PM_2.5, indoor/outdoor dust, drinking water and soil) were measured to explore the predominant lead pollution sources and exposure pathways of children. The results showed that the LIRs of children's blood (²⁰⁸Pb/²⁰⁶Pb = 2.0703 ± 0.0076, ²⁰⁷Pb/²⁰⁶Pb = 0.8501 ± 0.0052) were similar to those of dogs' blood (²⁰⁸Pb/²⁰⁶Pb = 2.0696 ± 0.0085, ²⁰⁷Pb/²⁰⁶Pb = 0.8499 ± 0.0052), as well as similar to the LIRs of environmental media, i.e. children's food (²⁰⁸Pb/²⁰⁶Pb = 2.0731 ± 0.0057, ²⁰⁷Pb/²⁰⁶Pb = 0.8491 ± 0.0036) and coal (²⁰⁸Pb/²⁰⁶Pb = 2.0683 ± 0.017, ²⁰⁷Pb/²⁰⁶Pb = 0.8515 ± 0.01). Children and dogs had similar lead exposure pathways, but the contributions of each exposure pathway were different, i.e., 83.1% vs. 76.9% for children and dogs via food ingestion, 1.4% vs. 5.6% via particulate matter exposure, and 15.5% vs. 17.5% via household dust exposure, respectively. The contribution of food via ingestion to lead exposure remains dominant, and coal combustion is a main lead exposure source for children and domestic dogs.

Association between lower-level of environmental lead exposure and reactive and proactive aggression in youth: Sex differences

Lead exposure during childhood has been associated with a variety of negative outcomes, including antisocial/aggressive behavior. However, different subtypes of antisocial behavior have been found to have different neurobiological correlates, and it is unclear whether lead exposure is related to specific subtypes of aggressive behavior. The objective of the study was to examine relationships between childhood blood lead levels (BLL) and proactive and reactive aggression. Further, given prior findings of sex differences in the effects of lead exposure, we examine whether there are sex differences in these relationships. In a sample of 818 youth (47.2% girls) ages 10-13 in China, we assessed BLL and administered the Reactive Proactive Aggression Questionnaire. Results show that BLLs were associated with reactive, but not proactive aggression. There was a significant interaction between BLL and sex in predicting aggression; boys with higher BLL scored higher in both proactive and reactive aggression than boys with lower BLL, but these differences were not present for girls. These findings suggest that lead exposure may have broad effects on antisocial behavior, but that boys may be more susceptible than girls. These findings may provide insights to identifying protective factors that could be potential targets for intervention.

Lead content in automotive paints purchased at formal and informal outlets in Kenya

Lead (Pb) is added to automotive paints to prevent corrosion on metallic surfaces, for decorative colours, and for reflective properties to heighten visibility, and enhanced drying time, and durability. However, there are substitutes for all of these applications and Pb is highly toxic to human health and the environment. Through concerted efforts, leaded gasoline was phased out and currently, the focus is on lead-based paints. Leaded automotive paint used for spray painting activities often conducted in close proximity to human habitation raises public health concerns over possible exposure. This study was therefore undertaken to assess Pb levels in automotive paints frequently used by informal spray painters. A total of thirty-two (n = 32) cans of automotive paints were purchased in 4 sets of red, blue, green and white colours from eight formal and informal retail shops. Lead levels in the paint samples were analyzed in triplicates using Atomic Absorption Spectrophotometry. All the automotive paints from the informal retail shops had Pb levels that ranged from 220 to 2740 ppm, and exceeded the regulatory limit of 90 ppm. The blue paint from the informal store had the highest Pb levels which were 30 times of the set limit. On the contrary, the paints from the formal stores had significantly (p < 0.05) lower Pb levels that ranged from 80.7 to 580 ppm than those of the informal stores. Although only one paint sample from the former retail shop had Pb levels within the limit. In general, the elevated Pb levels in automotive paints that are used in an unregulated environment are potential sources of exposure and environmental contamination. The study urgently calls for enforcement of the regulatory limits and comprehensive Pb exposure assessments in this sector.

Associations between DNA methylation and genotoxicity among lead-exposed workers in China

Studies have shown that lead (Pb) exposure caused genotoxicity, however, the underlying mechanisms remain unclear. A mechanism may be via DNA methylation which is one of the most widely studied epigenetic regulations for cellular activities. Whether this is involved in Pb-induced genotoxicity has rarely been studied. Our study aimed to examine whether DNA methylation was associated with Pb exposure and genotoxicity, and to explore its potential mediating roles. A total of 250 Pb-exposed workers were enrolled. Blood lead levels (BLLs) and genotoxic biomarkers (Micronuclei and Comet) were analyzed. Methylation levels at CpG sites of LINE1 and Alu and promoter region of P53, BRCA1, TRIM36 and OGG1 were measured by pyrosequencing. Generalized linear model (GLM) combined with restricted cubic splines (RCS) were used to analyze relationships between Pb exposure, DNA methylation and genotoxicity. Mediation effect was used to explore mediating roles of DNA methylation. The distribution of BLLs was right-skewed and showed wide ranges from 23.7 to 636.2 μg/L with median (P₂₅, P₇₅) being 218.4 (106.1, 313.9) μg/L among all workers. Micronuclei frequencies showed Poisson distribution [1.94 ± 1.88‰] and Comet tail intensity showed normal distribution [1.69 ± 0.93%]. GLM combined with RCS showed that Alu methylation was negatively associated with BLLs, while P53 and OGG1 methylation were positively associated with BLLs. Micronuclei were negatively associated with Alu and TRIM36 methylation but positively with P53 methylation. Comet was positively associated with P53 and BRCA1 methylation. Mediation effect showed that Alu methylation mediated 7% effects on association between Pb exposure and micronuclei, whereas, P53 methylation mediated 14% and BRCA1 mediated 9% effects on association between Pb exposure and Comet. Our data show that Pb exposure induced changes of global and gene-specific DNA methylation which mediated Pb-induced genotoxicity.

The construction and validation of a lead exposure screening tool for pregnant women in Thailand (ThaiL8Is)

Objectives

To construct, validate, and implement a new screening tool for lead exposure in Thai pregnant women.

Methods

A cross-sectional study that included three processes: screening tool development, validation, and implementation. The participants were pregnant women who had received antenatal care at district health promotion hospitals. There were 100 pregnant women in Nakhon Si Thammarat province during the validation process, and 30 pregnant women in Phang Nga province during the implementation process. Blood lead levels (BLLs) were analysed by atomic absorption spectrophotometry. The sensitivity and specificity of the screening instrument, as well as the Area Under the Curve (AUC), demonstrate its validity.

Results

There were 80 BLL-related items found through the collection of primary and secondary data and examined for validity and inter-rater reliability by five experts. Six items were excluded because the values were less than the criteria set. Seventy-four items remained with the Item Content Validity Index (I-CVI) = 0.80-1.00, the Content Validity Index Average (S-CVI/Ave) = 0.91, and Kappa scores = 0.76-1.00. After using 74 items collected on pregnant women, only 31 items were included in the validation process. Following that, the pooled eight items with cut-off point scores of 1 had the highest validity, which included systolic blood pressure, diastolic blood pressure, urine sugar, haemoglobin level, occupation, drinking coffee, using chemical products, and education level (ThaiL8Is). The ThaiL8Is in the validation process yielded sensitivity = 80.9%, specificity = 69.8%, and an AUC (95%CI) = 0.78 (0.69-0.87). The implementation process has confirmed the validity of the screening tool; sensitivity = 78.9%, specificity = 81.8%, and the AUC (95%CI) = 0.80 (0.63-0.97).

Conclusions

The ThaiL8Is a valid screening tool for Thai pregnant women. ThaiL8Is' sensitivity in detecting the risk groups for lead exposure can be enhanced by a combination of biochemical markers used in routine prenatal screening. It can be used to screen pregnant women for early indicators of lead exposure prior to a blood lead test.

Elevated soil and blood lead levels with increasing residential proximity to a mine tailings facility in Soweto, South Africa

Mining has long been associated with the release of a range of toxic metals including lead, elevated levels of which have been found in land surrounding mine dumps as far afield as Spain, India, Macedonia and Nigeria. Mining has been a key pillar of economic development in South Africa for around a century and a half, and has left a legacy of major environmental contamination, with the poorest experiencing the highest burden of exposure. The current study was undertaken to ascertain the concentrations of lead in soil and in the blood of adults and children residing at increasing distances from a cluster of large tailings facilities (MTFs) in greater Johannesburg, South Africa. Through a cross-sectional survey data on household characteristics were collected through a questionnaire survey, and supplemented with samples of soil from household gardens, together with blood samples from child-adult pairs from all households included in the study. Soil lead concentrations decreased significantly (median = 35.7 mg/kg closest to the mine tailings facility (MTF) and 8.6 mg/kg at the furthest point in the study site) with increasing distance from the MTF. Blood lead levels were highest in both adults (median = 3.0 μg/dL) and children (median = 4.0 μg/dL) who lived closest (≤500 m) to the MTF, and lowest (1.4 μg/dL in adults and 2.5 μg/dL in children) in those who lived furthest away (4-5 km). The study findings point to a need for greater emphasis on the precautionary principle in environmental health and for health impact assessments to inform decisions on planning, especially with regard to the location of human settlements relative to major, polluting development initiatives.

Lead exposure promotes the inflammation via the circRNA-05280/miR-146a/IRAK1 axis in mammary gland

Lead, the most widely used heavy metal in industry, is detrimental to human health if exposed to living and occupational environment. Although several studies have been conducted on lead exposure, little has been reported on its harm to mammary gland and its mechanisms. In view of this, our study is the first to verify that lead exposure could promote apoptosis and inflammation in mouse mammary tissue (in vivo) and cow mammary epithelial cells (in vitro). After establishing a lead exposed mouse model, the expression profile of mammary gland tissue was constructed by high-throughput sequencing technology. In the profile, 917 differentially expressed genes were screened, of which IRAK1 was up-regulated by 4.33 times. Then, from qRT-PCR, Western blot and Luciferase report, IRAK1 was found to promote the release of inflammatory factors and tissue apoptosis and could be a specific target of miR-146a. On the other hand, double luciferase reporter system and qRT-PCR predicted the existence of a binding site between circRNA-05280 and miR-146a sequence. Experiments such as immunohistochemistry, apoptosis and EdU demonstrated that circRNA-05280 could promote not only cell apoptosis but also the expression level of inflammatory genes. Nevertheless, the function of miR-146a is opposite to that of circRNA-05280. Specifically, circRNA-05280 can regulate the level of apoptosis and inflammation of mammary gland by binding miR-146a and releasing the expression of miR-146a on target gene IRAK1. This study concludes that circRNA-05280/ miR-146a/ IRAK1 signaling pathway could mediate the mammary gland damage resulting from lead exposure. Accordingly, it sheds new light on further exploration of molecular mechanisms of mammary gland tissue damage caused by lead exposure, the risk assessment of lead, and the mechanism of lead mammary gland toxicity.

Childhood lead exposure and sex-based neurobehavioral functioning in adolescence

It is well documented that childhood lead exposure is associated with long-term decreases in intelligence quotients (IQ). Lesser known is the relationship with neurobehavioral domains, especially in adolescence. This study sought to identify cross-sectional and longitudinal associations between lead exposure and adolescent executive and visual-motor functioning and examine sex-based differences. Participants were 681 children from Jintan, China who had their blood lead levels (BLLs) assessed at age 3-5 years and 12 years old and neurobehavioral functioning assessed through the University of Pennsylvania Computerized Neurocognitive Battery (PennCNB) platform http://www.med.upenn.edu/bbl at 12 years old. Mean BLLs were 6.41 mcg/dl at age 3-5 years and 3.10 mcg/dl at 12. BLLs at 3-5 years and 12 years were used as predictors for the individual neurobehavioral domains in general linear models while controlling for father and mother occupation and education, residence location, age, and adolescent IQ. Models were run separately for males and females. In adjusted models, males BLLs at 3-5 years were associated with increased time to correctly complete tasks in multiple domains including abstraction/flexibility (β = 19.90, 95% CI( 4.26, 35.54) and spatial processing (β = 96.00, 95% CI 6.18, 185.82) at 12 years. For females in adjusted models, BLLs at 3-5 years were associated with increasing time to correctly complete tasks on the episodic memory domain task (β = 34.59, 95% CI 5.33, 63.84) at 12 years. Two adolescent cross-sectional relationships remained in the adjusted models for males only, suggesting a positive association between BLLs and increasing time for correct responses on the attentional domain task (β = 15.08, 95% CI 0.65, 29.51) and decreasing time for correct responses on the episodic memory task (β = -73.49, 95% CI -138.91, -8.06) in males at 12 years. These associations remained with and without controlling for IQ. These results suggest that lead exposure is associated with overall deficits in male and female neurobehavioral functioning, though in different domains and different timing of exposure.

On the authenticity of Beethoven's skull fragments from the estate of Prof. Dr. Romeo Seligmann

On the occasion of the reburial of Beethoven's mortal remains in 1863, skull fragments are said to have come into the possession of Prof. Dr. Seligmann, who was present at that time and had conducted scientific investigations. These fragments were inherited in his family and are currently housed in the USA. Their authenticity is doubted by some scientists. On the basis of a plaster cast of Beethoven's skull kept in the Natural History Museum, Fool's Tower, in Vienna, the exact topographical position of these skull fragments could be reconstructed and it could be shown that there is no indication that the fragments did not originate from Beethoven's skull.

Estimating the burden of diseases attributable to lead exposure in the North Africa and Middle East region, 1990-2019: a systematic analysis for the Global Burden of Disease study 2019

BACKGROUND

Lead exposure (LE) and its attributable deaths and disability-adjusted life years (DALYs) have declined in the recent decade; however, it remains one of the leading public health concerns, particularly in regions with low socio-demographic index (SDI) such as the North Africa and Middle East (NAME) region. Hence, we aimed to describe the attributable burden of the LE in this region.

METHODS

Data on deaths, DALYs, years of life lost (YLLs), and years lived with disability (YLDs) attributable to LE in the NAME region and its 21 countries from 1990 to 2019 were extracted from the Global Burden of Disease (GBD) 2019 study.

RESULTS

In 2019, the age-standardized death and DALY rates attributable to LE were 23.4 (95% uncertainty interval: 15.1 to 33.3) and 489.3 (320.5 to 669.6) per 100,000 in the region, respectively, both of which were higher among men than women. The overall age-standardized death and DALY rates showed 27.7% and 36.8% decreases, respectively, between 1990 and 2019. In this period, Bahrain, the United Arab Emirates, and Turkey had the highest decreases in the age-standardized death and DALY rates, while Afghanistan, Egypt, and Yemen had the lowest ones. Countries within high SDI quintile had lower attributable burden to LE compared with the low SDI quintile. Cardiovascular diseases and chronic kidney diseases accounted for the 414.2 (258.6 to 580.6) and 28.7 (17.7 to 41.7) LE attributable DALYs per 100,000 in 2019, respectively. The attributable YLDs was 46.4 (20.7 to 82.1) per 100,000 in 2019, which shows a 25.7% reduction (-30.8 to -22.5%) over 1990-2019.

CONCLUSIONS

The overall LE and its attributed burden by cause have decreased in the region from 1990-2019. Nevertheless, the application of cost-effective and long-term programs for decreasing LE and its consequences in NAME is needed.

How long-term metal and lead exposure among foundry workers affect COVID-19 infection outcomes in Jordan

Foundry workers face a number of occupational health hazards, which may lead to an increased risk of respiratory disease, cancer, and anxiety level and are associated with endocrine, hematologic, renal, and neurological problems in humans. This study aims to evaluated thyroid functions, glutathione level, and the risk of infection with SARS-CoV-2 after vaccinated (two doses of the BNT162b2 mRNA COVID-19 vaccine) foundry workers in Jordan. We examined the efficacy BNT162b2 vaccine by calculating the rate of mortality and the degree of severity from mild to severe respiratory infections in 105 adult males foundry workers occupationally exposed to metals and Pb who had been received two doses, 21 days apart, of the BNT162b2 vaccine. Seventy-five male subjects not exposed to the Pb and who received two shots of the BNT162b2 vaccine (Pfizer-BioNTech) served as the control group. In foundry workers who were infected with COVID-19, the mortality rate (0%) was similar as in the control group (0%), and increased transmission of infection with SARS-CoV-2; the non-hospitalized infections increased nearly 3.4-times and hospitalized infections increased 4.29-times among people exposed to lead and metal contamination compared to the healthy persons control group. Also, among the foundry workers, the blood lead, FT3, and FT4 levels were significantly higher (p < 0.0001) and the levels of glutathione and TSH were significantly decreased (p < 0.0001) compared with the control group. In conclusion, long-term exposure to Pb is associated with a risk of infection with COVID-19 despite the 2 doses of the BNT162b2 vaccine (Pfizer-BioNTech). Also, exposure to Pb is associated with hyperthyroidism and a reduction in glutathione.

Molecular mechanisms of mechanical function changes of the rat myocardium under subchronic lead exposure

A moderate degree of lead intoxication was observed in male rats after repeated intraperitoneal injections with two doses of lead acetate three times a week during 5 (12.5 mg of Pb per kg body mass) and 6 (6.01 mg of Pb per kg body mass) weeks. Using an in vitro motility assay, we investigated the impact of this intoxication on the characteristics of actin-myosin interaction and its regulation in the atria, right, and left ventricles. Both lead doses exposure decreased the maximum sliding velocity of reconstituted thin filaments over myosin and fraction of motile filaments in all heart chambers, caused the myosin isoforms shift towards slower β-myosin heavy chains in ventricles and decreased regulatory light chain phosphorylation in atria. No statistically significant difference was found in force and calcium regulation of actin-myosin interaction. A dose-dependent effect of lead on myosin functional characteristics was found in all heart chambers, but the degree of this effect varied depending on the heart chamber.

Global magnitude and temporal trends of idiopathic developmental intellectual disability attributable to lead exposure from 1990 to 2019: Results from Global Burden of Disease Study

As an important environmental pollutant, lead exposure can result in idiopathic developmental intellectual disability (IDII). However, the latest spatiotemporal patterns across the world are unclear. Therefore, in this study, the global burden of lead exposure-related IDII was assessed using the Global Burden of Disease (GBD) study (2019). The data were downloaded from the Institute for Health Metrics and Evaluation (IHME), and the estimated annual percentage change (EAPC) was calculated to assess the changing trend of the age-standardized disability-adjusted life-years (DALYs) rates (ASDR) of global IDII attributed to lead exposure. In 2019, the number of global DALYs of IDII attributed to lead exposure was 2.72 million, the corresponding ASDR was 35.70 per 100,000. The ASDR was highest in children and adolescents, and low- and middle-income countries. From 1990 to 2019, the global number of DALYs of IDII attributable to lead exposure increased by 7.89%, while the ASDR of IDII decreased by 19.19% [EAPC = -0.78, 95% confidence interval (CI): (-0.90, -0.66)]. The downward trends were seen in most GBD regions and countries, especially in high-income countries, but 11 countries presented an upward trend. Therefore, it is important to continue to improve primary mental healthcare globally, especially in low- and middle-income countries. Meanwhile, the implementation of effective strategies to reduce lead exposure should be continually strengthened.

Association between lead exposure and DNA damage (genotoxicity): systematic review and meta-analysis

Studies suggest that chronic lead (Pb) exposure may induce deoxyribonucleic acid (DNA) damage. However, there is no synthesised evidence in this regard. We systematically reviewed existing literature and synthesised evidence on the association between chronic Pb exposure and markers of genotoxicity. Observational studies reporting biomarkers of DNA damage among occupationally Pb-exposed and unexposed controls were systematically searched from PubMed, Scopus and Embase databases from inception to January 2022. The markers included were micronucleus frequency (MN), chromosomal aberrations, comet assay, and 8-hydroxy-deoxyguanosine. During the execution of this review, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Mean differences in the biological markers of DNA damage between Pb-exposed and control groups were pooled using the random-effects model. The heterogeneity was assessed using the Cochran-Q test and I² statistic. The review included forty-five studies comparing markers of DNA damage between Pb-exposed and unexposed. The primary studies utilised buccal and/or peripheral leukocytes for evaluating the DNA damage. The pooled quantitative results revealed significantly higher DNA damage characterised by increased levels of MN and SCE frequency, chromosomal aberrations, and oxidative DNA damage (comet assay and 8-OHdG) among Pb-exposed than the unexposed. However, studies included in the review exhibited high levels of heterogeneity among the studies. Chronic Pb exposure is associated with DNA damage. However, high-quality, multicentred studies are required to strengthen present observations and further understand the Pb's role in inducing DNA damage. CRD42022286810.

Does short-term, airborne lead exposure during pregnancy affect birth outcomes? Quasi-experimental evidence from NASCAR's deleading policy

BACKGROUND

There is evidence of a weak placental-fetal barrier to lead, suggesting that maternal lead exposure could affect the fetus. The health consequences for newborns from in utero lead exposure are not well understood.

OBJECTIVES

We estimated the effects by trimester, of short-term (<1 week), airborne lead exposure during pregnancy on birth outcomes.

METHODS

We use quasi-experimental variation in airborne lead exposure during pregnancy, based on NASCAR's deleading of racing fuel in 2007, in a difference-in-differences model, to estimate the effect of deleading on the birth outcomes of all live births (n = 147,673) in the Charlotte-Concord-Gastonia Metropolitan Statistical Area between 2004 and 2009.

RESULTS

After deleading, children born to mothers residing <4000 m of Charlotte Motor Speedway (relative to those residing >10,000 m) experienced an average increase in birthweight (BW) of 102.50 g [P < 0.001]. The probability of low birthweight (LBW) declined by 0.045 [P = 0.001], preterm (PRE) births by 0.03 [P = 0.04], and small for gestational age (SGA) by 0.04 [P = 0.002]. We find that benefits accrue primarily in preterm LBW and SGA babies, and from decreased lead exposure in the first trimester.

CONCLUSIONS

Short-term exposure to airborne lead during pregnancy adversely affects birth outcomes. Reducing even very brief exposure to airborne lead during pregnancy may improve birth outcomes.

Occupational lead exposure on genome-wide DNA methylation and DNA damage

Lead (Pb) exposure can induce DNA damage and alter DNA methylation but their inter-relationships have not been adequately determined. Our overall aims were to explore such relationships and to evaluate underlying epigenetic mechanisms of Pb-induced genotoxicity in Chinese workers. Blood Pb levels (BLLs) were determined and used as individual's Pb-exposure dose and the Comet assay (i.e., % tail DNA) was conducted to evaluate DNA damage. In the screening assay, 850 K BeadChip sequencing was performed on peripheral blood from 10 controls (BLLs ≤100 μg/L) and 20 exposed workers (i.e., 10 DNA-damaged and 10 DNA-undamaged workers). Using the technique, differentially methylated positions (DMPs) between the controls and the exposed workers were identified. In addition, DMPs were identified between the DNA-undamaged and DNA-damaged workers (% tail DNA >2.14%). In our validation assay, methylation levels of four candidate genes were measured by pyrosequencing in an independent sample set (n = 305), including RRAGC (Ras related GTP binding C), USP1 (Ubiquitin specific protease 1), COPS7B (COP9 signalosome subunit 7 B) and CHEK1 (Checkpoint kinase 1). The result of comparisons between the controls and the Pb-exposed workers show that DMPs were significantly enriched in genes related to nerve conduction and cell cycle. Between DNA-damaged group and DNA-undamaged group, differentially methylated genes were enriched in the pathways related to cell cycle and DNA integrity checkpoints. Additionally, methylation levels of RRAGC and USP1 were negatively associated with BLLs (P < 0.05), and the former mediated 19.40% of the effect of Pb on the % tail DNA. These findings collectively indicated that Pb-induced DNA damage was closely related to methylation of genes in cell cycle regulation, and methylation levels of RRAGC were involved in Pb-induced genotoxicity.

MiR-378a-3p/ SLC7A11 regulate ferroptosis in nerve injury induced by lead exposure

An increasing number of studies have clarified that ferroptosis plays a vital role in neurodegenerative diseases, which is characterized by the accumulation of Fe²⁺, lipid peroxidation, and alteration of mitochondrial structure. However, whether ferroptosis is involved in nerve injury caused by lead exposure remains unclear. In this study, HT22 cells and mice were treated with lead acetate to investigate the role of ferroptosis in lead neurotoxicity. The results showed that lead exposure resulted in an accumulation of Fe²⁺, an increase in malondialdehyde (MDA) levels, and a decrease in glutathione (GSH) levels in vivo and in vitro. An increase in the levels of lipid reactive oxygen species (ROS) and the expression of 4HNE, as well as the change in mitochondrial morphology, were also observed in HT22 cells treated with lead acetate. In addition, deferoxamine (DFO; an iron chelator) attenuated the accumulation of Fe²⁺ and significantly enhanced the viability of HT22 cells exposed to lead. Fer-1 (an anti-ferroptosis agent) reduced the level of lipid ROS and expression of 4HNE in lead-treated HT22 cells. Furthermore, lead exposure sharply downregulated the expression of SLC7A11 in HT22 cells. Overexpression of SLC7A11 reversed the changes in MDA and GSH levels and cell viability induced by lead exposure. In contrast, lower expression of SLC7A11 accelerated the changes in these parameters. Consequently, we screened miRNAs that regulate SLC7A11 using TargetScan. We found that miR-378a-3p showed the highest expression among the target miRNAs regulating SLC7A11 expression. Inhibition of miR-378a-3p expression reversed the reduction in GSH and the increase in lipid ROS levels induced by lead exposure. Taken together, these findings indicate that lead exposure can cause ferroptosis and that miR-378a-3p exerted an important effect by regulating SLC7A11 expression. Our findings provide new insights into the mechanisms underlying the effects of lead exposure.

Effects of single and combined exposure to lead and stress during pregnancy on offspring neurodevelopment

Objective

To assess associations of single and combined exposures to lead and stress during different stages of pregnancy with offspring neurodevelopment.

Methods

We measured prenatal lead (maternal blood-lead in early-pregnancy and umbilical-cord-blood-lead) and maternal stress levels in Shanghai-Birth-Cohort from 2013 to 2016. Maternal stress was assessed using Center-for-Epidemiological-Studies-Depression-Scale and Self-Rating-Anxiety-Scale during mid-pregnancy. The Ages-Stages-Questionnaires-3 (at 6/12-months-of-age) and Bayley-III (at 24-months-of-age) were both used to assess neurodevelopment.

Results

A total of 2132 mother-child pairs with both prenatal lead and stress measurements were included. The geometric-means of blood-lead in early-pregnancy and cord-blood-lead were 1.46 μg/dL and 1.33 μg/dL, respectively. Among the study women, 1.89 % and 0.14 % were screened positive for depression and anxiety. Adjusting for related confounders, the combined exposures had stronger adverse associations with offspring social-emotional skills than single exposures; and the combined exposure in early-pregnancy was associated with greater neurodevelopmental differences than combined exposure around-birth, especially in social-emotion at 24 months-of-age [β (95 %CI): − 10.48(−17.42, −3.54) vs. − 5.95(−11.53, −0.36)].

Conclusions

Both single and combined prenatal exposures to lead/stress impaired infant neuro-development, and the effects of combined exposure may be more profound than single exposures. Combined exposure in early-pregnancy may be associated with worse neurodevelopmental outcomes than combined exposure around-birth, especially in social-emotional development.

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Effects of prenatal single and combined exposure to lead and stress were investigated using a large-scale birth cohort.

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The overall levels of prenatal exposures to lead/stress were relatively low in the Shanghai study women.

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Adverse effects of prenatal combined exposure on offspring neurodevelopment may be more profound than single exposure.

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The impaired neurodevelopment domains in the offspring mainly include social-emotional development.

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Higher levels of impairments were induced when the combined exposure occurred in an earlier stage of pregnancy.

Therapeutic Effects of Sodium Para-Aminosalicylic Acid on Cognitive Deficits and Activated ERK1/2-p90RSK/NF-κB Inflammatory Pathway in Pb-Exposed Rats

Lead (Pb) is a toxic heavy metal and environmental pollutant that adversely affects the nervous system. However, effective therapeutic drugs for Pb-induced neurotoxicity have yet to be developed. In the present study, we investigated the ameliorative effect of sodium para-aminosalicylic acid (PAS-Na) on Pb-induced neurotoxicity. Male Sprague-Dawley rats were treated with (CH₃COO)₂ Pb•4H₂O (6 mg/kg) for 4 weeks, followed by 3 weeks of PAS-Na (100, 200, and 300 mg/kg). The results showed that subacute Pb exposure significantly decreased rats body-weight gains and increased liver coefficient, and impaired spatial learning and memory. HE staining showed that Pb damaged the structure of the hippocampus. Moreover, Pb activated the ERK1/2-p90^RSK/ NF-κB pathway concomitant with increased inflammatory cytokine IL-1β levels in rat hippocampus. PAS-Na reversed the Pb-induced increase in the liver coefficient as well as the learning and memory deficits. In addition, PAS-Na reduced the phosphorylation of ERK1/2, p90^RSK and NF-κB p65, decreasing IL-1β levels in hippocampus. Our findings indicated that PAS-Na showed efficacy in reversing Pb-induced rats cognitive deficits and triggered an anti-inflammatory response. Thus, PAS-Na may be a promising therapy for treating Pb-induced neurotoxicity.