Low Blood Lead Levels Research Articles

Association Between Lead Exposure and Red Blood Cell Folate Concentrations in U.S. Children Aged 2–17 Years: An Analysis of Data from NHANES 2007–2018

The objective of this study is to evaluate the impact of low blood lead levels (BLLs) on the red blood cell folate concentrations in U.S. children aged 2–17 years. All data were obtained from the National Health and Nutrition Examination Survey (NHANES) over six consecutive cycles from 2007–2008 to 2017–2018. A total of 12,739 children with BLLs lower than 10 µg/dL (geometric mean: 0.66 µg/dL) were included in the dataset. BLLs were categorized into three tertiles (tertile 1: <0.55 µg/dL; tertile 2: 0.55–0.95 µg/dL; and tertile 3: ≥0.95 µg/dL). The multivariate linear regression model analysis indicates a negative relationship between BLLs and red blood cell folate concentrations. After adjusting for potential confounding factors, red blood cell folate concentrations were lower in children in the BLL tertile 2 (β-coefficient = −0.0450; 95% CI: −0.0676, −0.0224) and BLL tertile 3 groups (β-coefficient = −0.0775; 95% CI: −0.1032, −0.0517) compared to children in the BLL tertile 1 group. When stratified by age, gender, and race/Hispanic origin, the subgroup analysis consistently revealed a negative relationship between BLLs and red blood cell folate concentrations, with red blood cell folate concentrations being lower (p < 0.05) in children in the BLL tertile 3 group compared to children in the tertile 1 group. Further investigation is needed to explore the mechanism underlying the potential relationship between BLLs and red blood cell folate concentrations and determine whether folate plays an active role beneficial for preventing the harmful effects of lead on children.

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

PurposeChildhood 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.MethodsA 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 3–5 years (mean 6.50 ± 2.76 μg/dL) and 11–13 years (mean 3.12 ± 1.17 μg/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).ResultsBoth 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.ConclusionFindings 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.

Exploring Blood Lead Level Determinants in Refinery Workers: A Cross-Sectional Study.

Occupational lead exposure poses a significant risk to workers in industrial settings, especially in petroleum refineries. The study aimed to examine the prevalence and determinants of high blood lead concentrations among refinery workers in Kirkuk, Iraq. It has also been aimed to provide evidence-based approaches to identify associated risk factors. A cross-sectional study was conducted among 187 workers from three departments (transportation, storage, and production) in a petroleum refinery from August 2023 to April 2024. Blood lead levels (BLLs) were measured using graphite furnace atomic absorption spectroscopy (GFAAS)(Agilent, Santa Clara, CA). The elevated BLLs were defined as lead levels in blood samples greater than 10 µg/dL. Data on demographic characteristics, such as occupations, smoking habits, and drinking milk, were collected using a researcher-developed information sheet. Statistical analyses included the Kruskal-Wallis test and Pearson Chi-Square test, and logistic regression was used to address the determinants of elevated BLLs. The corresponding associations were reported using odds ratios (OR) and adjusted OR(AOR) along with 95% confidence intervals (CIs). Eighty-five percent of the workers had high BLLs, with a median BLL of 17.11 µg/dL. The findings revealed that workers employed in outdoor settings had 4.25 times higher AOR(95% CI: 1.24-14.48) of experiencing high BLLs compared to those working indoors, after adjusting for other factors. This was especially true for workers who spent nine to 16 hours outdoors. Additionally, age and smoking were also found to be associated with an increased risk of high BLLs. On the other hand, the analysis indicated that drinking milk had a protective effect against high BLLs. The high prevalence of elevated BLLs among refinery workers in Kirkuk underscores the urgency for immediate interventions. Regular monitoring of BLLs, improved training, dietary adjustments (e.g., consuming calcium and phosphate-rich milk, which can help lower BLLs), and smoking cessation programs are recommended to reduce lead exposure and safeguard workers' health. Furthermore, the results suggest that drinking milk could potentially reduce BLLs among petroleum refinery workers. Additional research is necessary to evaluate the effectiveness of these interventions and to continue monitoring exposure levels.

Association between breakfast skipping and blood levels of lead and cadmium in children and adolescents aged 6–17 years: Results from the National Health and Nutrition Examination Survey 2013–2018

IntroductionPrevious research suggests that fasting increases lead absorption in the gastrointestinal tract, and that regularly eating meals may reduce blood lead. However, there is insufficient evidence linking breakfast status and blood-metal levels in children. We assessed the cross-sectional association between breakfast consumption status and children and adolescent’s blood levels of lead and cadmium. We also explored blood hemoglobin, serum ferritin, and age group as potential effect modifiers of these associations. MethodsThis analysis included children and adolescents aged 6–17 years who participated in the National Health and Nutrition Examination Survey (NHANES) cycles 2013–2018 with complete data on breakfast consumption status (consumers vs. skippers), blood metals, and covariates (N=3722). Blood metal variables were log-transformed. Crude and covariate-adjusted, survey-weighted linear regression models were conducted for each blood metal outcome. Potential effect modification was explored using stratification. ResultsOverall fewer participants reported skipping breakfast (n=719) than eating breakfast (n=3003). Mean (SE) concentrations of blood lead and cadmium (µg/L) were 0.63 (0.01) µg/dL and 0.13 (0.00) µg/L, respectively. Children and adolescents who skipped breakfast were more likely to be female (51.2%), older (mean 12.2 years, SE = 0.1), have a higher body mass index (mean 22.8 kg/m2, SE = 0.2), and a lower income-poverty ratio (mean 1.7, SE = 0.1) than breakfast consumers. No associations between breakfast consumption and any of the blood metals were found. When stratified by age (≤ 10, 11–13, and 14–17 years), children aged 11–13 years who consumed breakfast had lower log-transformed blood lead levels [β = −0.14 µg/L; 95% CI: (-0.25, −0.03)] compared to children of the same age who skipped breakfast. ConclusionChildren 11–13 years-old who were breakfast consumers had lower blood lead levels compared to children of the same age who skipped breakfast. Our results support that encouraging breakfast consumption among school-age children may contribute to lower blood lead levels.

Distribution of blood lead and cadmium levels in healthy children aged 0 to 18 years and analysis of related influencing factors in Henan, China: data findings from 2017 to 2022

BackgroundThere is still a lack of data on blood lead levels (BLLs) and blood lead levels (BLLs) in healthy children of all ages from 0 to 18 years in China. This study was performed to analyze the BLLs and BCLs in healthy children aged 0-18 years from 2017 to 2022 in urban and rural areas of Henan Province, Central China, as well as their relationships with socio-demographic variables and certain relevant exposure factors. To provide a basis for evaluating public health policy development and exposure risk management.MethodsThis was an observational study containing data from 17 prefecture-level cities in Henan, China. Blood Pb and Cd levels were determined using a triple quadrupole inductively coupled plasma mass spectrometer equipped with an autosampler. We first calculated the concentrations of Pb and Cd elements in participants of different genders, ages and years, and then created visual graphs depicting the distribution of each element in terms of gender, age and year (2017-2022). The rates between different groups were compared using the Chi-square test or Fisher exact test (if applicable). The means were compared by one-way ANOVA, medians were compared with the Kruskal-Wallis rank-sum test. Generalized linear models (GLM) were performed to estimate the effects of various factors on blood Pb and Cd concentrations in children.ResultsWe recruited a total of 25,920 children (16,142 boys and 9,778 girls) aged 0.01 to 18.00 years (2.58 (1.00,6.25)). The median of BLLs was 23.48µg/L, around 9.39% of studied children had elevated BLLs. The median of BCLs was 0.66µg/L, around 1.84% of studied children had elevated BCLs. The median blood Pb concentration was higher in boys (23.90µg/L) than in girls (22.75µg/L) (P<0.001). The median blood Pb concentration was highest in the 3-7 years group (24.51µg/L) and the median blood Cd concentration was highest in the 1-3 years group (0.66µg/L) among all age groups. Both BLLs and BCLs were substantially higher in children in 2020-2022 compared to 2017-2019. Rural children had lower BLLs and higher BCLs. The results of the generalized linear model showed that children in households using Oil, coal, pellet or other wood as a fuel for heating, children with higher frequency of exposure to tobacco smoke and beverage intake had significantly increased chances of elevated BLLs and BCLs.ConclusionsPb and Cd exposure of children in this area is relatively low, but associated risk factors continue to exist in vulnerable populations. This study is the first big data analysis of Pb and Cd in children in Henan, China, and provides baseline information for future research.

Association between relatively low blood lead levels and urinary δ-aminolevulinic acid concentrations among male workers at a Japanese battery factory.

Whether the known positive association between blood lead (PbB) levels and urinary δ-aminolevulinic acid (ALAU) also exists at relatively low PbB levels (<40μg/dL) remains unclear. We aimed to investigate this association at lower PbB levels. We analyzed data from biannual medical examinations of workers at a Japanese factory from August 2013 to August 2023. We excluded records from female workers and those with missing data, resulting in a dataset consisting of 1396 records from 155 male workers. We employed mixed-effect linear regression models with a random intercept for workers and additional adjustments for age and smoking status. The median PbB level across all the analyzed records was 8μg/dL (range: 1-31μg/dL). Significant positive associations were observed between PbB and ALAU, with a 1-unit increase in natural logarithm-transformed PbB corresponding to a 10.0% increase in ALAU (95% CI, 2.7%-17.9%). Categorized PbB analyses showed a 23.8% increase in ALAU (95% CI, 2.7%-49.2%) for PbB levels at 20-24μg/dL and an 83.1% increase (95% CI, 30.1%-157.7%) for PbB levels ≥25μg/dL, compared with those <5μg/dL. The exposure-response curve analysis indicated a plateau followed by an increasing trend. A positive and nonlinear association between PbB and ALAU levels was observed at relatively low PbB levels.

Assessing Cross-Sectional Association of Uremic Pruritus with Serum Heavy Metal Levels: A Single-Center Study

(1) Background: Uremic pruritus (UP) is a common and taxing symptom in patients on maintenance hemodialysis (MHD). We have previously shown that blood lead levels (BLLs) and blood aluminum levels (BALs) were separately positively associated with UP in MHD patients. We also found that blood cadmium levels (BCLs) were positively associated with all-cause mortality and cardiovascular-related mortality in MHD patients. We wondered whether there is any correlation between BCLs and UP after adjusting for BLLs and BALs. (2) Methods: Patients enrolled in this study were all from three hemodialysis (HD) centers at Chang Gung Memorial Hospital, Lin-Kou Medical Center, including both the Taipei and Taoyuan branches. Correlations between UP and BLLs, BALs, BCLs, and other clinical data were analyzed. (3) Results: Eight hundred and fifty-three patients were recruited. Univariate logistic regressions showed that diabetes mellitus, hepatitis B virus infection, hepatitis C virus infection, HD duration, hemodiafiltration, dialysis clearance of urea, normalized protein catabolic rate, non-anuria, serum albumin levels, log (intact-parathyroid hormone levels), total serum cholesterol levels, serum low-density lipoprotein levels, log (blood aluminum levels), and log (blood lead levels) were associated with UP. Although log BCLs were not significantly associated with UP (p = 0.136) in univariate analysis, we still included log BCLs in multivariate logistic regression to verify their effect on UP given that our aim in this study was to verify associations between serum heavy metals and UP. Multivariate logistic regressions showed that log BLLs (OR: 27.556, 95% CI: 10.912–69.587, p &lt; 0.001) and log BALs (OR: 5.485, 95% CI: 2.985–10.079, p &lt; 0.001) were positively associated with UP. The other logistic regression, which stratified BLLs and BALs into high and low BLLs and BALs, respectively, showed that high BLLs or high BALs (low BLLs and low BALs as reference) (OR: 3.760, 95% CI: 2.554–5.535, p &lt; 0.001) and high BLLs and high BALs combined (low BLLs and low BALs as reference) (OR: 10.838, 95% CI: 5.381–21.828, p &lt; 0.001) were positively correlated with UP. (4) Conclusions: BLLs and BALs were positively correlated with UP. BCLs were not correlated with UP. Clinicians should pay more attention to the environmental sources of lead and aluminum to prevent UP.

Association between Chronic Environmental Lead (Pb) Exposure and Cytokines in Males and Females of Reproductive Age from Kabwe, Zambia.

Lead (Pb) poisoning remains a great public health challenge globally known to induce a wide range of ailments in both children and adults. The current study investigated the association of chronic environmental Pb exposure and immunomodulatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-8 (IL-8) in adult males and females living in Kabwe, Zambia. The standard human cytokine/chemokine Milliplex assay was used to quantify plasma cytokines from four groups categorized as low (<10 μg/dL) and high (>10 μg/dL) blood lead level (BLL) groups, namely, low BLL female (n = 47; BLL = 3.76 μg/dL), low BLL Male (n = 43; BLL = 4.13 μg/dL), high BLL female (n = 21; BLL = 23.5 μg/dL), and high BLL male (n = 18; BLL = 23.7 μg/dL), respectively. The low BLL group was associated with increased TNF-α levels, and the high BLL group was associated with reduced TNF-α levels in female subjects. No associations between BLL and the levels of IL-8 and TNF-α cytokines were observed in either females or males, respectively. A negative correlation between BLL and TNF-α was found in female subjects, suggesting that an increase in BLL accompanied by a reduction in TNF-α. The reduced levels of circulating TNF-α in female subjects suggest that chronic Pb exposure could predispose females to immune and inflammation-related disorders than their male counterparts. Further studies are recommended to ascertain the impact of chronic Pb exposure on immunomodulatory cytokines, especially in females.

Nine kinds of novel cytokines identified in children with lead exposure

Lead (Pb) is a neurotoxic heavy metal element with many recognized adverse health side effects, and its main target of lead toxicity is the central nervous system. The mechanism of lead toxicity is still uncertain. However, there are few studies investigated the cytokines changes caused by lead exposure in children. The BLLs was quantified using flame atomic absorption spectroscopy. The novel cytokines were detected by RayBio@ Human Cytokine Antibody Array. A total of 4 children with elevated blood lead levels (BLLs) and 4 children with low BLLs were chosen in the study. Volcano plot analysis was performed to identify significant proteins, with the criteria: P value &lt;0.05 and log2 fold change &gt;1. The mean BLLs of children with elevated BLLs (5.675±1.018 μg/dL) has significant difference compared with those with low BLLs (1.975±0.3966 μg/dL) (P=0.0148, t=3.385). And 9 kinds of novel cytokines were identified. The expression of IL-6, IL-8 and IL-17 was significantly up-regulated, while the expression of BDNF, BMP-4, IGF-1, IL-7, IL-10 and Leptin was significantly down-regulated.

Exposure to lead and cadmium is associated with fasting plasma glucose and type 2 diabetes in Chinese adults.

Exposure to lead and cadmium has been associated with type 2 diabetes, but the results are largely inconsistent, and little is known about their joint effect. We aimed to investigate the associations of lead and cadmium co-exposure with fasting plasma glucose (FPG) and type 2 diabetes. The study included 5732 participants aged ≥18years from 16 communities in East China. Blood levels of lead and cadmium were determined using graphite furnace atomic absorption spectrometry. Multivariable linear and logistic regression models were performed to evaluate the associations of lead and cadmium alone or in combination with FPG and diabetes. The median (interquartile range) values of blood lead and cadmium were 40.0 (26.8-57.9) and 1.70 (0.56-3.60)μg/L, respectively. After adjustment for potential confounders, blood lead levels were positively associated with FPG (difference comparing extreme lead quartiles=0.11 [95% CI: 0.03, 0.20]mmol/L) and prevalent diabetes (odds ratio [OR]=1.35 [95% CI: 1.03, 1.78]). The association between lead and diabetes was observed among participants with high cadmium, but not among those with low cadmium (P for interaction=0.03). In the joint analysis, compared with participants with low levels of blood lead and cadmium, participants with high levels of two metals had a 0.16 (95% CI: 0.07, 0.25) mmol/L increase in FPG and a 51% (OR=1.51, 95% CI: 1.15, 1.99) increase in odds of diabetes. Our findings suggest that lead and cadmium co-exposure is significantly associated with elevated FPG and type 2 diabetes in the general population.

Blood Lead Levels among Non-Occupationally Exposed Pregnant Women in Southern Thailand

Lead (Pb) is a heavy metal that is toxic to humans, especially children and pregnant women. In Thailand, guidelines exist to minimize lead exposure in pregnant women working in lead-related occupations. However, no guidelines exist for pregnant women who are not employed in these economic sectors. This cross-sectional study aimed to examine blood lead levels (BLLs) and related risk factors among 80 non-occupationally exposed pregnant women from the general population living in Nakhon Si Thammarat province, Southern Thailand. BLLs were determined by graphite furnace atomic absorption spectrophotometry. A validated questionnaire was adopted to interview participants which included demographic, consumer goods, supplement intake, and health factors. The mean BLL was 4.68 ± 1.55 µg/dL (95% CI 4.33–5.02) and 42.50% had BLLs ≥ 5 µg/dL. Higher education was the only demographic factor associated with BLLs ≥ 5 µg/dL (aOR 0.16, 95% CI 0.03–0.80, p = 0.027). Systolic blood pressure was also associated with BLLs ≥ 5 µg/dL (aOR 5.00, 95% CI 1.23–17.16, p = 0.023). However, consumer goods and supplement intake were not associated with BLLs. Our results indicate that pregnant women from the general population who were not in the risk exposure group had lead in their bodies. Except for education, demographics were not associated with pregnant women with BLLs. However, with health factors, even low BLLs had a small effect on systolic blood pressure. These data suggest a need for promoting health education and health interventions to prevent the dangers of lead exposure, especially for pregnant women and children.

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.

Industries With the Highest Occupational Blood Lead Test Results, California Occupational Blood Lead Registry, 2020‒2021.

Objectives. To evaluate the focused surveillance of blood lead results of 20 micrograms per deciliter (µg/dL) of venous blood and higher received by the California Occupational Blood Lead Registry (Registry) because of new legislation concerning occupational lead poisoning. Methods. We used occupational blood lead results reported to the Registry from January 1, 2020, to December 31, 2021, to describe the current industries with workers having the highest levels of lead poisoning. Results. The Registry received 239 blood lead levels (BLLs) of 20 µg/dL or higher for 151 adults with occupational lead exposure in 28 industries over the study period. Worker BLLs ranged from 20 µg/dL to 55 µg/dL. The industries with the greatest number of workers were storage battery manufacturing, painting contractors, and shooting ranges. Conclusions. Occupational lead poisoning is a health concern across numerous industries in California. The current outdated state and federal occupational lead standards would not require removal from lead work for any of the workers in this study despite extensive evidence of harm at lower BLLs. Strengthened standards could support public health initiatives for worker protection and reduce take-home lead to family members. (Am J Public Health. 2022;112(S7):S690-S694. https://doi.org/10.2105/AJPH.2022.307002).

Lung cancer incidence among workers biologically monitored for occupational exposure to lead: a cohort study.

Earlier studies have reported increased risks of lung, kidney and brain cancers for exposure to lead. The International Agency for Research on Cancer (IARC) Working Group evaluated inorganic lead and its compounds probably carcinogenic to humans. This study aimed to assess the association between blood lead level in occupational exposure and risk of lung cancer. The study was based on the follow-up of lung cancer incidence during 1973-2014 among 20 729 employees biologically monitored for their occupational lead exposure in 1973-1983. Duration of employment in the monitored work was assessed using records from the Finnish Centre for Pensions; and potential confounding by other occupational carcinogens using longitudinal information on the occupation in censuses and the Finnish National Job-Exposure Matrix (FINJEM). Occupation- and gender-specific prevalence of regular tobacco smoking and the socioeconomic status were also utilized in the adjustments for potential confounding. Positive trends were found for the elevated blood lead levels on the lung cancer risk. Among employees with the duration of employment of ≥60 months, the relative risk (RR) of lung cancer was 1.72 [95% confidence interval (CI) 1.28-2.31] for mean blood lead 1.0-1.9 µmol/L and RR 2.63 (95% CI 1.71-4.05) for mean blood lead ≥2.0 µmol/L, compared with mean lead <0.5 µmol/L. The studied potential confounders did not explain the findings on the increased risk for lead exposure. The current study lends support to the findings that exposure to lead increases lung cancer risk. Increased risks were seen already at rather low blood lead levels.

Low level lead exposure in early childhood and parental education on adolescent IQ and working memory: a cohort study.

The independent effect of lead exposure and parental education on children's neurocognition is well-documented. However, few studies have examined the combined effect of childhood lead exposure and parental education on adolescent neurocognition, especially in China. Examine both the combined and interactive effect of childhood blood lead levels (BLLs) and parental education on early adolescent neurocognition. 417 children from a longitudinal cohort study in Jintan, China had BLLs measured at 3-5 years and 12 years, parental education levels assessed at 3-5 years, and neurocognitive outcomes tested at 12 years. BLLs at 3-5 years were inversely associated with adolescent IQ (β -0.55 95% CI: -0.97, -0.13) but not working memory (β -0.06 95% CI: -0.23, 0.11) and parental education was positively associated with adolescent IQ (β 0.68 95% CI: 0.19, 1.17) and working memory (β 0.24 95% CI: 0.04, 0.44). BLLs and parental education evidenced combined effects on neurocognition, where children with higher BLLs and lower fathers' education had mean IQ scores 7.84 (95% CI: -13.15, -2.53) points lower than children with lower BLLs and higher fathers' education. There were significant associations between parental education and working memory, however, not with BLLs. The interaction between mother and father high school education and BLLs was insignificant for effects on IQ and working memory. Childhood lead exposure and parental education levels have a combined and long-term impact on IQ, evidence that may partially explain disparities in lead exposure associated outcomes and highlight those children at greatest risk for neurocognitive deficits. Children continue to be exposed to low-levels of environmental lead in China and globally, warranting examination of the impact of such exposures. This paper demonstrates that even relatively low-level lead exposure in early childhood significantly influences adolescent neurocognitive functioning. Furthermore, co-existing social determinant of health-related variables, measured here as parental education, have a combined impact on neurocognition. These results highlight children at greater risk for neurocognitive deficits and demonstrate the need to examine the influence of lead exposure within the broader socio- ecological environment, as these factors work in tandem to influence longer-term neurocognitive outcomes.

Estimation of blood lead levels in the French population using two complementary approaches: Esteban (2014–2016) as part of the human biomonitoring program and the national surveillance system for childhood lead poisoning (2015–2018)

BackgroundUsed widely for centuries, lead is a common environmental pollutant. As a cumulative toxic, its presence in the body is always evidence of exposure, and health effects occur without threshold. Though regulated by European directives, lead requires close monitoring due to its environmental persistence and toxicity. MethodsThe first data source was the French surveillance system for monitoring childhood lead poisoning, which records the screening results of children (−18 years), providing data on their temporal and geographical distribution, characteristics, and risk factors. The second data source was Esteban, a cross-sectional study conducted in 2014–2016 on a random sample of the French population as part of the human biomonitoring program. The Esteban lead study concerns 904 children (6–17 years) and 999 adults (18–74 years), providing data on biological samples, sociodemographic characteristics, occupational exposure, environmental and dietary factors. ResultsThe surveillance system highlighted that lead poisoning affected 10% of children screened between 2015 and 2018. The main risk factor remains housing. Esteban confirmed this observation, finding a general mean of blood lead level (BLL) at 9.9 and 18.5 μg/L for children and adults, respectively. In children, parents’ occupation increased BLLs. In adults, the greatest exposure factors were smoking, age, place of residence, alcohol, bread-based products, and homegrown livestock products. In both, drinking tap water and year of housing construction increased BLLs. ConclusionsThe surveillance system showed a high number of children with lead poisoning despite the implementation of prevention measures, which mainly concern lead paints in old and degraded homes. To help identify children at risk, healthcare providers need to know about exposure from housing and the emerging sources identified in the Esteban survey. Despite lower BLLs, the well-known risk factors of lead exposure persist, meaning prevention efforts must continue in order to limit their impact on the population.

Associations between exposure to different heavy metals and self-reported erectile dysfunction: a population-based study using data from the 2001-2004 National Health and Nutrition Examination Survey.

Heavy metals are ubiquitous and nonbiodegradable pollutants that are widely distributed in the environment. Heavy metal exposure can damage various biological tissues and cause several diseases. This study aimed to investigate the association between blood and urinary cadmium, lead, and mercury levels and erectile dysfunction (ED) based on data from the 2001-2004 National Health and Nutrition Examination Survey. In total, 3681 participants were included in the analysis. Results showed that participants with ED had high blood cadmium, mercury, creatinine, urinary lead, cadmium levels, low blood lead, serum cotinine, and urinary mercury levels. Multivariate logistic regression analysis showed that only blood cadmium level was an independent risk factor of ED (tertile [T]2 vs T1: odds ratio = 1.495, 95% confidence interval: 1.181-1.892, p = 0.001; T3 vs T1: odds ratio = 2.089, 95% confidence interval: 1.554-2.809, p < 0.001). The dose-response curve showed a positive nonlinear association between blood cadmium and lead levels and ED and a negative nonlinear association between blood and urinary mercury levels and ED after propensity score matching. In conclusion, heavy metal exposure is closely correlated with the development of ED, and a high blood cadmium level is an independent risk factor of ED.

Early-Life Pb Exposure Might Exert Synapse-Toxic Effects Via Inhibiting Synapse-Associated Membrane Protein 2 (VAMP2) Mediated by Upregulation of miR-34b.

Early-life Pb exposure can cause behavioral and cognitive problems and induce symptoms of hyperactivity, impulsivity, and inattention in children. Studies showed that blood lead levels were highly correlated with neuropsychiatric disorders, and effects of neurotoxicity might persist and affect the incidence of neurodegenerative diseases, for example Alzheimer's disease (AD). To explore possible mechanisms of developmental Pb-induced neuropsychiatric dysfunctions. Children were divided into low blood lead level (BLL) group (0-50.00μg/L) and high BLL group (> 50.00μg/L) and blood samples were collected. miRNA array was used to testify miRNA expression landscape between two groups. Correlation analysis and real-time PCR were applied to find miRNAs that altered in Pb and neuropsychiatric diseases. Animal models and cell experiments were used to confirm the effect of miRNAs in response to Pb, and siRNA and luciferase experiments were conducted to examine their effect on neural functions. miRNA array data and correlation analysis showed that miR-34b was the most relevant miRNA among Pb neurotoxicity and neuropsychiatric disorders, and synapse-associated membrane protein 2 (VAMP2) was the target gene regulating synapse function. In vivo and in vitro studies showed Pb exposure injured rats' cognitive abilities and induced upregulation of miR-34b and downregulation of VAMP2, resulting in decreases of hippocampal synaptic vesicles. Blockage of miR-34b mitigated Pb's effects on VAMP2 in vitro. Early-life Pb exposure might exert synapse-toxic effects via inhibiting VAMP2 mediated by upregulation of miR-34b and shed a light on the underlying relationship between Pb neurotoxicity and developmental neuropsychiatric disorders.

Age at Menarche in Urban Girls Exposed to Lead in the Copper Basin, Poland.

Simple SummaryLead is an environmental pollutant that negatively affects human growth, development and health. However, research into its effect on age at menarche (first menstruation), a proxy for maturation, is, to some extent, inconclusive. In this study, we identified that lower than currently acceptable blood lead level was related to later menarche. However, body weight and fatness had a moderating effect on this relationship, decreasing its significance.Lead negatively affects human growth and development. In this research, we aimed to assess the effect of elevated blood lead level on age at menarche (AM), controlling for body mass index (BMI) and estimated fatness. The sample included 490 girls aged 7–16 examined in Polkowice town (Copper Basin, Poland) in 2008. Measurements included height, weight, skinfold thicknesses and estimated percentage of body fat. AM was assessed using the status quo method. Blood samples were taken for lead level assessment. Two groups were defined based on the median blood lead level for the total sample of children (3.7 µg/dL). Logistic regression models were used to assess the association between AM and independent variables. The results indicated that menarche in the higher blood lead level group was significantly later compared to the lower blood lead level group (p < 0.01). This relationship remained only marginally significant when BMI (p < 0.10), sum of skinfolds (p < 0.09) or percentage of fat (p < 0.08) were controlled. The results revealed that a lower blood lead level (3.7 µg/dL) than the currently acceptable threshold (5 µg/dL) is related to a later AM; however, this relationship is moderated by body fatness, which may decrease its significance.

Developmental Pb2+ -Exposure Induces Cardiovascular Pathologies in Adult Male Rats

Background: Developmental lead (Pb2+) exposure has been historically shown to alter the pathological functions of the cardiovascular system at high blood lead levels (i.e.,&gt;15 μg/dL). However, given the time that has elapsed in the field (i.e., some 30 years), there is a great need for less clinical and more basic research on the cardiopathology of low blood lead levels (lBLLs; i.e.,&lt;10 μg/dL). Further, most of the prior literature had focused solely on males as they had been reported to be more vulnerable to Pb2+ induced cardiovascular pathology. Aims and Objectives: To generate a model system of Pb2+-induced cardiovascular pathology that would be consistent with past reports, the present study examined male Long–Evans Hooded rats that were perinatally Pb2+ exposed (i.e., via their food with 996 ppm lead acetate in the rat chow) up until weaning (i.e., postnatal day 22; blood lead levels [BLLs]: 10–15 μg/dL) and were then removed from Pb2+ exposure for nearly 1.5 months (i.e., BLLs &gt;3.33 μg/dL). Materials and Methods: Rats were then subjected to cardiovascular measures of systolic and diastolic blood pressures (SBP and DBP) and heart rates. Rats were sacrificed and their hearts were weighed; their thoracic aortas were collected and examined for microstructural and morphological changes through a scanning electron micrograph. Results: The data showed that compared to age matched control rats, the Pb2+ exposed rats have increased SBP, DBP, and heart rate with no differences in heart weight. These data show that early developmental Pb2+ exposure comprising lBLLs can cause significant cardiovascular pathological changes in rats. Conclusion: The present model of developmental Pb2+-exposure occurring early in life caused Pb2+-induced cardiopathology later in life through increased hypertension and reduced elasticity of the aorta media. These cardiovascular pathologies could further increase the likelihood of accelerated fronto executive dysfunctions due to the direct action of Pb2+ on neurons through inhibition of calcium dependent processes and might also contribute to vascular dementias.