Elevated Blood Lead Levels Research Articles

Biomonitoring of lead in blood of children living in a former mining area in Lower Saxony, Germany

Environmental exposure to lead substantially decreased over the past decades. However, soil of former mining areas still contains high lead levels. We therefore performed a biomonitoring study among children living in two former mining communities in Lower Saxony, Germany. In these communities, soil contains lead levels of 1000 to 30,000 mg/kg. Overall, 75 children (6–10 years of age) attending the two primary schools of the study area took part in the study. Parents completed a short questionnaire on sociodemographics, and children provided capillary whole blood samples. We analysed lead using inductively coupled plasma tandem mass spectrometer. We compared the results to current German (20 μg/l for boys, 15 μg/l for girls) and US (35 μg/l) reference values. Potential associations between questionnaire information and lead results were tested using lead as continuous outcome and using lead dichotomized at the reference values. Finally, we analysed spatial patterns of elevated biomonitoring results. Of all children, 48% exceeded the German reference values for lead (5% expected) and 8% the US reference value (2.5% expected). Children 6–8 years of age were more likely to exceed German reference values (63%) than 9–10 year old children were (32%; pFisher = 0.01). No other questionnaire information was statistically significantly associated with biomonitoring results. Additionally, we did not find any indication of spatial clustering. In conclusion, we observed elevated blood lead levels in primary school children living in a former mining area. In the next step, exposure pathways need to be identified to implement effective public health measures.

An inferential spatiotemporal approach for knowledge synthesis to identify trends in public health research

BackgroundDecisions follow patterns that are introduced by human perception. Research and development (R&D) are influenced by these patterns. Furthermore, R&D publications can represent repetitive attempts to solve similar, or the same problems. Literature reviews serve as an important tool for identifying these trends, but they are time consuming. The time commitment of a literature review can be reduced by using a sample of research. This will allow an infinite population of research to be generalized. Additionally, spatiotemporal analysis is most appropriate for fields that follow time and geographic trends, such as public health. Also, using research locations to perform this analysis potentially captures the social return of R&D, as knowledge gained. As a result, an inferential spatiotemporal methodological framework is introduced to quickly identify research trends using public health research. This was applied to a childhood Pb exposure case study. MethodsA body of more than 1000 childhood elevated blood lead (Pb) level (EBLL) research articles were used to extract publication years, research locations, and subtopics. These publications were grouped into research locations (i.e., U.S. states where research was conducted; not publication location) and averaged over years published (i.e., 29 years). Binary indicator variables were derived using the subtopics extracted and the periods identified in time trend analyses. Explanatory variables were used to conduct hypothesis testing. Significant variables were used to generalize the population of the annual average EBLL articles written per state. ResultsThe range of the annual average of EBLL research articles by state was 0–1.7 articles, with a mean of 0.3 articles. Thirty-eight explanatory variables suggested a significant effect on research article production. These included temporal, sociodemographic, education, structure age, environmental, and economic variables. The strongest effect on research production for U.S. states came from the number of structures built before 1950. A predictive model was selected to generalize the population of articles using time-periods 1990-95, environmental subtopic, and structures built before 1950. The locations with the most research production for this topic were California and New York. The locations with the least research production for this topic were Alaska, Hawaii, Nevada, Wyoming, North Dakota, South Dakota, Mississippi, Delaware, and New Hampshire. ConclusionIf the trend for R&D is to make fast decisions, more human bias will be introduced into the decision-making process. Analytical tools that enable researchers to identify trends and ask more questions about their field will mitigate these biases. This hypothesis testing and predictive modeling methodology provide researchers and other decision makers with analytical tools they can use to quickly identify research trends and narrow their field of research. Additionally, this analysis potentially captures the impact of discovered ideas, as a social return spillover, for this topic.

Effect of Environmental and Socioeconomic Factors on Increased Early Childhood Blood Lead Levels: A Case Study in Chicago.

This study analyzes the prevalence of elevated blood lead levels (BLLs) in children across Chicagoland zip codes from 2019 to 2021, linking them to socioeconomic, environmental, and racial factors. Wilcoxon tests and generalized additive model (GAM) regressions identified economic hardship, reflected in per capita income and unemployment rates, as a significant contributor to increased lead poisoning (LP) rates. Additionally, LP rates correlate with the average age of buildings, particularly post the 1978 lead paint ban, illustrating policy impacts on health outcomes. The study further explores the novel area of land surface temperature (LST) effects on LP, finding that higher nighttime LST, indicative of urban heat island effects, correlates with increased LP. This finding gains additional significance in the context of anthropogenic climate change. When these factors are combined with the ongoing expansion of urban territories, a significant risk exists of escalating LP rates on a global scale. Racial disparity analysis revealed that Black and Hispanic/Latino populations face higher LP rates, primarily due to unemployment and older housing. The study underscores the necessity for targeted public health strategies to address these disparities, emphasizing the need for interventions that cater to the unique challenges of these at-risk communities.

Lead occurrence in North Carolina well water: importance of sampling representation and collection techniques

Private wells often lack centralized oversight, drinking water quality standards, and consistent testing methodologies. For lead in well water, the lack of standardized data collection methods can impact reported measurements, which can misinform health risks. Here, we conducted a targeted community science testing of 1143 wells across 17 counties in North Carolina (USA) and compared results to state testing data primarily associated with new well construction compiled in the NCWELL database. The goal of our study was to explore the impacts of sampling methodology and household representation on estimated lead exposures and subsequent health risks. At the household scale, we illustrated how sampling and analytical techniques impact lead measurements. The community science testing first draw samples (characterizing drinking water) had a 90th percentile lead value of 12.8 μg l−1 while the NCWELL database flushed samples (characterizing groundwater) had a value below the reporting level of 5 μg l−1. As lead was associated with the corrosion of premise plumbing, flushing prior to collection substantially reduced lead concentrations. At the community scale, we examined how the lack of representation based on household demographics and well construction characteristics impacted the knowledge of lead and blood lead level (BLL) occurrence. When simulating representative demographics of the well populations, we observed that the 90th percentile lead level could differ by up to 6 μg l−1, resulting in communities being above the USEPA action level. This translated to a 1.0–1.3 μg dl−1 difference in predicted geometric mean BLL among infants consuming reconstituted formula. Further, inclusion of less common well construction types also increased lead in water occurrence. Overall, under- and overestimations of lead concentrations associated with differences in sampling techniques and sample representation can misinform conclusions about risks of elevated BLLs associated with drinking water from private wells which may hinder investigations of waterborne lead exposure.

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.

Firearm-Related Lead Exposure and Child Lead Levels in the United States, 2012-2018

ObjectiveTo determine if firearm ownership is positively related to elevated child lead levels at a state-level, even when accounting for other sources of lead. Study designFor this cross-sectional ecological study, we investigated whether household firearm ownership rates (a proxy for firearm-related lead exposure) was associated with the prevalence of elevated child blood lead levels in 44 US States between 2012 and 2018. To account for potential confounding, we adjusted for other known lead exposures, poverty rate, population density, race, and calendar year. To address missing data, we used multiple imputation by chained equations. ResultsPrevalence of elevated child blood lead positively correlated with household firearm ownership and established predictors of lead exposure. In fully adjusted negative binomial regression models, child blood lead was positively associated with household firearm ownership and older housing; each interquartile range (14%) increase in household firearm ownership rate was associated with a 41% higher prevalence of childhood elevated blood lead (prevalence ratio: 1.41, 95% CI: 1.11-1.79). ConclusionThese data provide state-level evidence that firearms may be an important source of child lead exposure. More research is needed to substantiate this relationship and identify modifiable pathways of exposure at the individual level.

The role of geophagy and artisanal gold mining as risk factors for elevated blood lead levels in pregnant women in northwestern Tanzania.

Neither artisanal and small-scale gold mining (ASGM) or geophagy practices have received substantial attention related to blood lead levels despite the well documented deleterious effects of lead. This cross-sectional analytical study aimed to document the risk of lead exposure from geophagy and mining-related occupational activities for pregnant women. The study recruited 1056 pregnant women (883 in an ASGM area and 173 in a non-ASGM area) between April 2015 -April 2017. Generalized Linear Model with an identity link function was used to model the association between blood lead levels (BLLs) and geophagy practices and involvement in gold mining. The prevalence of geophagy was 36.2% (95% CI: 33.6, 39.4%) and 6.3% engaged in mining as a primary occupation. Practicing geophagy increased BLLs by 22% (β = 1.22, 95% CI: 1.116, 1.309, p<0.0001). Living in a gold mining area increased BLLs by 33.4% (β = 1.334, 95% CI: 1.2, 1.483, p<0.0001). Having mining as a primary occupation increased BLLs by 1.3% β = 1.013, 95% CI: 0.872, 1.176, p = 0.869) even though the association was not statistically significant. Socioeconomic wealth quantile (β = 1.037, 95% CI: 1.021, 1.054, p<0.001) increased blood lead levels by 3.7%. Developing a comprehensive inventory capturing sources of community-level lead exposure is essential. Further, increasing public health campaigns and education are crucial to limit geophagy practices and to minimize work in gold mining activities during pregnancy.

Гормональные, биохимические показатели и уровни микроэлементов крови у молодых женщин с субклиническим гипотиреозом в сочетании с носительством антител к тиреопероксидазе

Many studies have been devoted to investigating the relationship between subclinical hypothyroidism (SH), thyroid gland (TG) autoimmunity, and blood trace elements; however, the data presented in these studies are often contradictory. Aim of study. To identify the factors associated with SH in combination with the presence of Anti-thyroid peroxidase antibody (TPO-Ab). Design. Single-center, observational, single-cohort, cross-sectional, and uncontrolled study. Materials and Methods. This study analyzed 859 women aged 18–45 with SH and without TG dysfunction. Based on thyroid function and TPO-Ab status (presence (+) or absence (–)), four study groups were formed: Group 1 — Euthyroidism and TPO-Ab(–) (n = 503); Group 2 — Euthyroidism and TPO-Ab(+) (n = 164); Group 3 — SH and TPO-Ab(–) (n = 128); Group 4 — SH and TPO-Ab(+) (n = 64). Determination of thyroid-stimulating hormone (TSH), free thyroxine (FT4), and TPO-Ab levels in serum was provided by enzyme immunoassay on the Evolis Robotized System using the test systems "Thyroid-ELISA-TSH, 0.23–3.4 µIU/ml", "Thyroid-ELISA FT4, 10–23.2 pmol/l", and "Thyroid ELISA-TPO-Ab &lt; 30 U/ml". The reference values were taken from the instructions of the manufacturer Alkor Bio Group (Russia). Measurement of element concentrations was conducted on the atomic absorption spectrometer "МГА-915МД" from Lumex (Russia). Logistic regression analysis with a series of univariate and multivariate models was performed to determine independent predictors of the likelihood of SH and TPO-Ab positive status (relative to euthyroid and TPO-Ab negative individuals). Results. In young women, a decrease in FT4 is associated with increasing age, elevated levels of TSH, TPO-Ab, mercury, decreased heart rate, and reduced levels of thyroglobulin, alkaline phosphatase (ALP), manganese, nickel, selenium, lead, and the triglyceride/glucose index. An increase in TSH is associated with lower levels of ALP, manganese, and nickel, and higher mercury levels. The likelihood of having SH combined with the presence of TPO-Ab, compared to the group without thyroid dysfunction and elevated antibodies, increases with reduced concentrations of iodine (odds ratio (OR) = 0.739; 95% confidence interval (CI): 0.618–0.884, p = 0.001), selenium (OR = 0.987; 95% CI: 0.976–0.998, p = 0.018), and zinc (OR = 0.998; 95% CI: 0.997–0.999, p = 0.023), and with elevated lead levels (OR = 1.106; 95% CI: 1.006–1.217, p = 0.038). In a multivariate regression model, the probability also increases with decreased iodine and cadmium levels, and elevated lead levels. Conclusion. Reduced concentrations of iodine, selenium, and zinc, along with elevated blood lead levels, are factors associated with the activation of thyroid autoimmunity and the presence of SH in combination with elevated TPO-Ab levels. Keywords: thyroid gland, thyroid function hormones, microelements, thyroid peroxidase antibodies, young age, women.

Blood lead levels in pregnant women and their newborn infants at an Indian teaching hospital.

With the growth of the world's economy and industrialization, lead (Pb) contamination in the environment has become a major issue on a global scale. Lead is typically linked to unfavorable pregnancy outcomes such as stillbirth, low birth weight preterm, and spontaneous abortion. In this study, we evaluated the blood lead levels of pregnant women and their birth outcomes attending an Indian tertiary care teaching hospital, those who were not exposed to any lead-associated industry or shops. A descriptive study was undertaken to evaluate blood lead estimation in pregnant women and umbilical blood lead levels in a community hospital. Blood samples from 104 mothers during the 1st trimester, 90 mothers during 3rd trimester, and from the umbilical cord were collected. Self-administered questionnaires were used to collect information on demographics, medical history, and concerns linked to pregnancy. Following acid digestion, the levels of lead in whole blood were determined by an atomic absorption spectrometer. The DNA damage in high blood lead-concentrated pregnant women was evaluated by comet assay methods. Among 194 blood samples of pregnant women, 31 (15.98%) samples revealed ≥5 μg/dL blood lead levels. High lead concentration (≥5 µg/dL) in 1st trimester pregnant women, end of 3rd trimester and cord blood were detected 20.19%, 11.11% and 1.11% respectively. The mean blood lead levels in 1st trimester, 3rd trimester, and cord blood were 3.88 ± 3.19, 2.66 ± 1.82, and 1.53 ± 1.06 mg/dL, respectively. The blood lead concentrations were significantly higher in the 1st trimester of pregnancy than in the 3rd trimester of pregnancy (P < 0.0017). A positive correlation between maternal and infant blood lead levels was revealed (P < 0.0001). When the comet assay was used to assess the genotoxic consequences of elevated blood lead levels during pregnancy, higher amounts of DNA damage were found in the samples (P < 0.01). In this descriptive study, there was a significant amount of lead transferred from mother to baby through the placenta. All mothers were not exposed to lead-associated industry and most were housewives. This article may be viewed as an eye-opener for understanding the blood lead concentration during pregnancy to avoid abnormal birth outcomes. To minimize exposure to environmental lead, all possible measures should be undertaken.

Moderate selenium mitigates hand grip strength impairment associated with elevated blood cadmium and lead levels in middle-aged and elderly individuals: insights from NHANES 2011-2014.

Background: Selenium (Se) has been reported to have an antagonistic effect on heavy metals in animals. Nevertheless, there is a lack of epidemiological research examining whether Se can mitigate the adverse effects of cadmium (Cd) and lead (Pb) on hand grip strength (HGS) in middle-aged and elderly individuals. Methods: This study used data from the 2011-2014 National Health and Nutrition Examination Survey (NHANES). HGS measurements were conducted by trained examiners with a dynamometer. Concentrations of Se, Cd, and Pb in blood were determined via inductively coupled plasma mass spectrometry. We employed linear regression, restricted cubic splines, and quantile g-computation (qgcomp) to assess individual and combined associations between heavy metals and HGS. The study also explored the potential influence of Se on these associations. Results: In both individual metal and multi-metal models adjusted for confounders, general linear regression showed Se's positive association with HGS, while Cd and Pb inversely related to it. At varying Se-Cd and Se-Pb concentrations, high Se relative to low Se can attenuate Cd and Pb's HGS impact. An inverted U-shaped correlation exists between Se and both maximum and combined HGS, with Se's benefit plateauing beyond approximately 200μg/L. Stratified analysis by Se quartiles reveals Cd and Pb's adverse HGS effects diminishing as Se levels increase. Qgcomp regression analysis detected Se alleviating HGS damage from combined Cd and Pb exposure. Subsequent subgroup analyses identified the sensitivity of women, the elderly, and those at risk of diabetes to HGS impairment caused by heavy metals, with moderate Se supplementation beneficial in mitigating this effect. In the population at risk for diabetes, the protective role of Se against heavy metal toxicity-induced HGS reduction is inhibited, suggesting that diabetic individuals should particularly avoid heavy metal-induced handgrip impairment. Conclusion: Blood Cd and Pb levels are negatively correlated with HGS. Se can mitigate this negative impact, but its effectiveness plateaus beyond 200μg/L. Women, the elderly, and those at risk of diabetes are more vulnerable to HGS damage from heavy metals. While Se supplementation can help, its protective effect is limited in high diabetes risk groups.

Lead Toxicity from Retained Bullet Fragments in Soft Tissue

Introduction The full extent of adult lead poisoning and toxicity is difficult to ascertain because of limited data; existing data and research findings suggest that it remains an important environmental and public health problem even if population levels are decreasing. The prevalence of elevated lead levels is decreasing in the United States. The consequences of lead exposure may be reduced by taking an occupational and environmental health history, recognizing the early symptoms of elevated blood lead levels (BLLs) and lead poisoning, having a low threshold for suspecting asymptomatic lead exposure based on an occupational and environmental history or medical findings, and checking BLL in such cases to verify the diagnosis and provide appropriate advice and treatment. Case Presentation A 19-year-old Hispanic male presented to the emergency department with symptoms of worsening abdominal pain, anorexia, weight loss (10 lbs. over 2 months), constipation, low back pain, right knee pain, and headache that has been going on for two weeks. Complete blood counts showed microcytic anemia with a peripheral smear showing basophilic stippling; Computerized tomography of the head, abdomen, and pelvis showed no acute findings. Iron profile was within normal limits. Upon careful history and examination, he revealed that he had suffered an accidental gunshot injury to his right knee 6 years ago with retained bullet and had undergone a popliteal artery repair. His knee ray showed retained bullet fragment encased in a chronic calcified hematoma. This led us to suspect lead poisoning and ordering of venous lead level. His blood lead level came back and was elevated to a toxic level of 136.2 mcg/dl (Normal &amp;lt;5.0 mcg/dl). The patient was taken to the operation theatre for extraction of bullet fragments, and the hematoma that was evacuated showed that the inside of the capsule had blackish-grey discoloration possibly from lead. Simultaneously the patient was started on the chelating agent, Succimer. The patient's symptoms gradually improved and were at baseline with no active complaints. He was followed as an outpatient and lead levels were noted to be down trending. He continues to be followed with monthly checks of his blood lead levels. Discussion In lead poisoning, symptoms are most likely to occur in adults with blood lead levels (BLL) &amp;gt;80 mcg/dL. With BLL 40 to 80 mcg/dL, the symptoms are less severe and are variable. Adults with BLL &amp;lt;40 mcg/dL are usually asymptomatic and lead toxicity should be a diagnosis of exclusion. While acute intoxication leads to gastrointestinal, musculoskeletal, neuropsychiatric, and hematological effects, chronic exposure is linked to increased risks of mortality from oncological and cardiovascular causes. Because lead poisoning often presents with nonspecific symptoms and signs, the diagnosis must be suspected based on exposure, occupational history, and other associated symptoms. BLL should be obtained as this forms the basis upon which management and decisions are made. Chelation therapy is suggested for patients with a BLL &amp;gt;80 mcg/dL and all patients with a BLL &amp;gt; 100 mcg/dL. At a minimum, for patients with BLL &amp;lt;10 mcg/dL, surveillance with repeat BLL testing should be done at least annually if lead exposure continues. For BLL 10 to 29 mcg/dL, a repeat BLL should be obtained every three months until BLL is reduced to &amp;lt;10 mcg/dL. For BLL &amp;gt;30 mcg/dL, BLL should be repeated every month.

Impact of the COVID-19 Pandemic on Childhood Lead Testing and Blood Lead Levels

ObjectiveTo evaluate the effect of the COVID-19 pandemic on childhood lead testing and blood lead levels. MethodsA retrospective analysis of lead tests and results was performed across 3 urban medical centers during the pre-COVID-19 (March 10, 2019–March 9, 2020) and COVID-19 (March 10, 2020–March 10, 2022) periods. Interrupted time series analysis with quasi-Poisson regression was used to evaluate changes in lead testing between study periods. The relationship between sociodemographic features with detectable (≧2 µg/dL) and elevated (≧3.5 µg/dL) blood lead levels (BLLs) was assessed with multivariable logistic regression. ResultsAmong a total of 16,364 lead tests across 10,362 patients, weekly testing rates significantly decreased during COVID-19 (relative risk (RR) 0.64, 95% (confidence interval) CI 0.53–0.78). Census tracts with the greatest proportion of pre-1950s housing had a stronger association with detectable BLLs during the COVID-19 period (pre-COVID-19 adjusted odds ratio (aOR) 1.73, 95% CI 1.35–2.20; aOR 2.58, 95% CI 2.13–3.12; interaction P value .014). When limited to 1 year following COVID-19 (March 10, 2020–March 10, 2021), the association between both elevated BLLs (pre-COVID-19: aOR 1.49, 95% CI 0.87–2.53; COVID-19: aOR 3.51, 95% CI 1.98–6.25; interaction P value .032) and detectable BLLs with pre-1950s housing were greater during the COVID-19 period (pre-COVID-19: aOR 1.73, 95% CI 1.35–2.20; COVID-19: aOR 2.56, 95% CI 1.95–3.34; interaction P value .034). ConclusionsThe COVID-19 pandemic led to a significant reduction in lead surveillance and magnified the effect of known risk factors for lead exposure. Concerted clinical, public health, and community advocacy are needed to address care gaps and excess cases of lead poisoning.

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.

Prevalence of elevated blood lead level in children with global developmental delay and its relation with parental and child attributes

Background: Lead, a potential neurotoxin, is found in soil, water and air as a result of its non-biodegradable nature. Common sources of lead toxicity in children are household paints, leaded pipes for water supply, canned food, coloured toys, herbal/folk remedies and electronic wastes. Along with this, other child and parental attributes have been found to contribute to elevated blood lead level (EBLL). Objectives were to estimate the prevalence and risk factors of EBLL in children with global developmental delay (GDD). Methods: This hospital based cross sectional study was conducted between October 2019 and October 2021 at department of paediatrics of JNMCH, AMU, Aligarh. Data regarding clinical and sociodemographic characteristics as well as parental attributes was collected and entered on pre-designed proforma. Results: Among 94 children with GDD mean BLL was found to be 6.72±6.46 mcg/dl and in their mothers it was 6.74±6.46 mcg/dl (p=0.984). A high prevalence of EBLL (&gt;5 mcg/dl) in children with GDD (53.20%) and their mothers (49.3%) was noted. Various child and parental attributes were identified as potential sources of exposure to lead. Conclusions: A high prevalence of EBLL in children with GDD in our study area might also suggest higher exposure from environmental sources such as soil, water, electronic waste, lead acid batteries, etc. For countries like ours which is rapidly undergoing industrialisation, these potential sources need to be identified promptly and swift action in this regard is needed in addition to preventive measures at personal and family levels.

Effects of dietary inflammatory index, blood lead levels, and flavonoid intake on stroke risk in older Americans: A cross-sectional study

ObjectivesWe aimed to investigate the relationship between dietary flavonoids, the dietary inflammatory index (DII), blood lead levels, and stroke and evaluate how these factors interact with one another in relation to stroke. Materials and MethodsWe analyzed data from 3675 older American adults aged ≥60 years, obtained from the National Health and Nutrition Examination Survey. Since this database does not specifically differentiate between hemorrhagic and ischemic strokes, our data include both types. We utilized the DII to assess the inflammatory potential of the diet, calculated using 24 h dietary recalls. To determine the association between dietary flavonoids, blood lead levels, DII, and stroke, we performed multivariate logistic regression, subgroup analysis, and restricted cubic splines. We modeled additive interactions to assess the relationship between blood lead levels and DII. ResultsA high intake of flavonols, flavan-3-ols, and total flavonoids correlated negatively with stroke risk, whereas blood lead levels had a positive association. After adjusting for confounders, stroke risk was found to increase with higher DII. Restricted cubic splines analysis revealed that flavan-3-ols, total flavonoids, blood lead levels, and DII were linearly related to stroke, while the relationships with flavonoids and flavonols were nonlinear. Additionally, a significant interaction was detected between high DII and elevated blood lead levels in relation to stroke risk. ConclusionsIntake of flavan-3-ol, flavanols, and total flavonoids is negatively associated with stroke risk, while higher blood lead levels and DII are positively related to it. High DII and elevated blood lead levels interact synergistically to influence stroke risk.

Screening for elevated blood lead levels using single hair strands: Accounting for external contamination

Hair has long been explored as a potential biomarker of lead exposure since lead is readily adsorbed into hair's keratinous matrix; however, the utility of hair as a biomarker for lead exposure is hampered by its susceptibility to external contamination: lead particles attach to the exposed hair surface, confounding estimates of endogenous concentrations. This study describes the development of a hair screening tool, in which the confounding influence of external contamination are mitigated by focusing on the unexposed hair root, to predict elevated blood lead levels (BLLs). This tool requires a single strand of scalp hair, which is analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Forty-four (44) workers with high potential for lead exposure, and 63 reference individuals (with no known lead exposure) volunteered for the study. Hair lead level (HLL) thresholds were developed using methods from clinical assessment to screen exceedances of BLL thresholds at 10 and 15 µg/dL. Hair from both groups showed significantly lower lead concentrations in below-scalp portions compared to above the scalp (above-scalp was 11.2 times higher in workers, and 3.7 times higher in reference group). Hair lead concentrations below the scalp in workers significantly predicted BLLs. HLL thresholds for screening BLLs were 0.60 mg/kg and 0.75 mg/kg for BLLs of 10 µg/dL and 15 µg/dL, respectively. These HLL thresholds yielded high sensitivity (>85%), and slightly lower specificity (67% and 33%, for BLL thresholds of 10 µg/dL and 15 µg/dL, respectively). This study provides reference HLLs in non-contaminated portions of hair (<0.097 mg/kg), shows the significance of external contamination on exposed portions of hair even in a reference population, and assesses the effectiveness of below-scalp hair as a biomarker of elevated lead exposure. This hair screening tool effectively predicted BLL exceedances and could be considered as a non-invasive alternative to blood sampling.

Nerve excitability test and lead toxicity: a case-control study

BackgroundAlthough conventional electrophysiological parameters have been proposed as clinical indicators for monitoring lead neuropathies, their correlations with blood lead level are weak. In this study, we investigated the applicability of nerve excitability tests (NETs) to evaluate lead intoxication.MethodsFourteen workers who were exposed to lead with an elevated blood level ranging from 17.8 to 64.9 µg/dL and 20 healthy controls with similar ages and body heights were enrolled. Both workers and controls underwent nerve conduction studies (NCSs), motor evoked potentials (MEPs) with transcranial magnetic stimulation (TMS), and NETs.ResultsNCSs showed prolonged distal latencies and decreased motor nerve conduction velocity of median nerves in the workers but without significant correlation to blood lead level (BLL). Significantly prolonged MEP latency was observed in the workers (+ 6 ms). NETs demonstrated hyperpolarized resting membrane potentials in stimulus-response curves and changes in the property of potassium channels under a hyperpolarized current in threshold electrotonus, implying that lead hyperpolarized nerves by interfering with potassium channels. NETs also showed a better correlation with BLL than conventional electrophysiological parameters.ConclusionsAxonal hyperpolarization and central conduction delay are more apparently reflecting elevated BLL than NCS. NET may have the potential for early detection of lead neuropathy.

Metabolomics insights into the effects of pre-pregnancy lead exposure on bone metabolism in pregnant rats

Today's women of childbearing age with a history of high lead (Pb) exposure in childhood have large Pb body burdens, which increases Pb release during pregnancy by promoting bone Pb mobilisation. The purpose of this study was to investigate the metabolic mechanisms underlying bone Pb mobilisation and explore the bone metabolism-related pathways during pregnancy. Drinking water containing 0.05% sodium acetate or Pb acetate was provided to weaned female rats for 4 weeks followed by a 4-week washout period, and then rats were co-caged with healthy males of the same age until pregnancy. Blood and bone tissues of the female rats were collected at gestational day (GD) 3 (early pregnancy), GD 10 (middle pregnancy), and GD 17 (late pregnancy), respectively. Pb and calcium concentrations, biomarkers for bone turnover, bone microstructure, serum metabolomics, and metabolic indicators were intensively analyzed. The results demonstrated that pre-pregnancy Pb exposure elevated blood lead levels (BLLs) at GD17, accompanied by a negative correlation between BLLs and trabecular bone Pb levels. Meanwhile, Pb-exposed rats had low bone mass and aberrant bone architecture with a larger number of mature osteoclasts (OCs) compared to the control group. Moreover, the metabolomics uncovered that Pb exposure caused mitochondrial dysfunction, such as enhanced oxidative stress and inflammatory response, and suppressed energy metabolism. Additionally, the levels of ROS, MDA, IL-1β, and IL-18 involved in redox and inflammatory pathways of bone tissues were significantly increased in the Pb-exposed group, while antioxidant SOD and energy metabolism-related indicators including ATP levels, Na+-K+-ATPase, and Ca2+-Mg2+-ATPase activities were significantly decreased. In conclusion, pre-pregnancy Pb exposure promotes bone Pb mobilisation and affects bone microstructure in the third trimester of pregnancy, which may be attributed to OC activation and mitochondrial dysfunction.

The Association of Children's Blood Lead Levels and Prevalence of Stunting in Tin Mining Area in Indonesia.

Metal mining and smelting activities are regarded as major sources of heavy metals such as lead, mercury, arsenic and cadmium in the environment and in humans living at the surrounding area. Among others, lead can enter and accumulate in the human body and be very influential in children's growth and development. This study aims to assess the association between children's blood lead levels and stunting in a mining area in Indonesia. A cross-sectional design was implemented by involving 193 children living in surrounding tin mining in Bangka Island, Indonesia. Venous blood was drawn and blood lead level was measured by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Stunting status was measured by anthropometry standing height and converted to sexand age-specific Z-scores based on World Health Organization (WHO) growth reference. Children's dietary intake was assessed using 24-hour dietary recall method. Statistics of chi-square test and multiple logistic regression were performed for the analyses. The geometric mean of Blood Lead Levels (BLLs) was 5.5 µg/dl (± 2.6 µg/dl; 95% CI: 5.1-5.9). The interquartile range of BLLs and height for age Z-score (HAZ) were 3.0 μg/dl and -1.5, respectively. The data revealed that 23.3% of children were stunted (HAZ < -2). The multiple logistic regression models suggest that elevated BLLs were an independent predictor of the stunting. The odds stunted blood lead concentration was elevated about 10times higher [adjusted odd ratio (AOR) = 9.75 (95% Confidence interval (CI): 3.1-30.7); p < 0.001] in comparison to the odds of normal BLLs.The BLLs of children at ages two to nine years were found associated with stunting after controlling of the mother›s education, residence and the intake of energy, protein, zinc, vitamin A, calcium and phosphorus. The study suggested that living in surrounding tin mining was dangerous for children›s health and their development.

Assessment of lead exposure in indoor shooters in central Poland

A steady increase in shooting practices is observed worldwide. Potential lead exposure at shooting ranges poses a risk to their employees and users, which is not widely reported outside of the USA, especially in Poland. Exposure to lead results from the use of bullets containing lead and the main route of exposure to this metal at shooting ranges is inhalation, i.e., during shooting or cleaning. The aim of this study was to assess lead exposure of employees and users in selected indoor shooting ranges in central Poland. Airborne lead concentrations at all locations in the shooting ranges were above Polish occupational exposure limit (OEL, 0.05 mg m−3). Elevated blood and urine lead levels, and decreased 4-aminolevulinic acid dehydratase activity (ALA-D) were found in subjects participating in shooting even for only a few (< 10) hours per week. Lead exposure at shooting ranges in central Poland, as indicated by elevated blood lead levels and decreased ALA-D activity, could represent an elevated risk for adverse health effects. Thus, information on the possible health consequences of lead exposure should be provided at these sites, and biomonitoring appears to be reasonable for regular workers and shooters.