Ultra-high-efficiency capture of lead ions over acetylenic bond-rich graphdiyne adsorbent in aqueous solution.

A satisfactory material with high adsorption capacity is urgently needed to solve the serious problem of environment and human health caused by lead pollution. Herein, hydrogen-substituted graphdiyne (HsGDY) was successfully fabricated and employed to remove lead ions from sewage and lead-containing blood. The as-prepared HsGDY exhibits the highest adsorption capacity of lead among the reported materials with a maximum adsorption capacity of 2,390 mg/g, i.e., ~five times larger than that of graphdiyne (GDY). The distinguished hexagonal hole and stack mode of HsGDY allows the adsorption of more lead via its inner side adsorption mode in one single unit space. In addition, the Pb 6s and H 1s hybridization promotes the strong bonding of lead atom adsorbed at the acetylenic bond of HsGDY, contributing to the high adsorption capacity. HsGDY can be easily regenerated by acid treatment and showed excellent regeneration ability and reliability after six adsorption-regeneration cycles. Langmuir isotherm model, pseudo second order, and density functional theory (DFT) demonstrated that the lead adsorption process in HsGDY is monolayer chemisorption. Furthermore, the HsGDY-based portable filter can handle 1,000 µg/L lead-containing aqueous solution up to 1,000 mL, which is nearly 6.67 times that of commercial activated carbon particles. And, the HsGDY shows good biocompatibility and excellent removal efficiency to 100 µg/L blood lead, which is 1.7 times higher than that of GDY. These findings suggest that HsGDY could be a promising adsorbent for practical lead and other heavy metal removal.

Mapping Blood Lead Levels in China during 1980-2040 with Machine Learning.

Lead poisoning is globally concerning, yet limited testing hinders effective interventions in most countries. We aimed to create annual maps of county-specific blood lead levels in China from 1980 to 2040 using a machine learning model. Blood lead data from China were sourced from 1180 surveys published between 1980 and 2022. Additionally, regional statistical figures for 15 natural and socioeconomic variables were obtained or estimated as predictors. A machine learning model, using the random forest algorithm and 2973 generated samples, was created to predict county-specific blood lead levels in China from 1980 to 2040. Geometric mean blood lead levels in children (i.e., age 14 and under) decreased significantly from 104.4 µg/L in 1993 to an anticipated 40.3 µg/L by 2040. The number exceeding 100 µg/L declined dramatically, yet South Central China remains a hotspot. Lead exposure is similar among different groups, but overall adults and adolescents (i.e., age over 14), females, and rural residents exhibit slightly lower exposure compared to that of children, males, and urban residents, respectively. Our predictions indicated that despite the general reduction, one-fourth of Chinese counties rebounded during 2015-2020. This slower decline might be due to emerging lead sources like smelting and coal combustion; however, the primary factor driving the decline should be the reduction of a persistent source, legacy gasoline-derived lead. Our approach innovatively maps lead exposure without comprehensive surveys.

Peppered with lead: An environmental forensics approach to identify the source of rising blood lead levels.

Despite the phase-out of lead-based products, lead contamination can still present a contemporary risk to public health. In situations where elevated blood lead cannot be attributed to common sources, detailed environmental investigation is needed to identify more elusive sources and manage harmful exposure pathways. We apply a forensics approach to assess common and elusive sources of lead in the home environment of two individuals with fluctuating blood lead levels in Sydney, Australia. Using multiple analytical lines of evidence (portable X-Ray Fluorescence spectrometry (pXRF), inductively coupled-plasma mass spectrometry (ICP-MS), lead isotopic compositional analysis (PbIC) and haematological assessment) a pewter pepper grinder containing lead (>6000 mg/kg; 70% bioavailable) was identified as a potential source. After removing the pepper grinder from the home, the couple's blood lead decreased to below the Australian intervention level of 5 µg/dL within a year (Person A: from 12.5 µg/dL in August 2020 to 4.4 µg/dL in March 2022; and Person B: 15.4 µg/dL in August 2020 to 2.1 µg/dL in July 2021). This case study demonstrates how environmental science investigations can play a crucial role in supporting people to take evidence-based action to improve their health.

Exposure to cadmium and lead is associated with diabetic kidney disease in diabetic patients.

BACKGROUND: Cadmium (Cd) and lead (Pb) exhibit nephrotoxic activity and may accelerate kidney disease complications in diabetic patients, but studies investigating the relation to diabetic kidney disease (DKD) have been limited. We aimed to examine the associations of Cd and Pb with DKD in diabetic patients. METHODS: 3763 adults with blood metal measurements and 1604 adults with urinary ones who were diabetic from National Health and Nutrition Examination Survey (NHANES) 2007-2016 were involved. Multivariate logistic regression models were used to analyze the associations of blood Cd (BCd), blood Pb (BPb), urinary Cd (UCd), and urinary Pb (UPb) with DKD. RESULTS: BPb, BCd, and UCd levels were higher among participants with DKD than diabetics without nephropathy, but UPb performed the opposite result. BPb and UCd were significantly associated with DKD in the adjusted models (aOR, 1.17 (1.06, 1.29);1.52 (1.06, 2.02)). Participants in the 2nd and 3rd tertiles of BPb and BCd levels had higher odds of DKD, with a significant trend across tertiles, respectively (all P-trend < 0.005). Multiplication interaction was also identified for BPb and BCd (P for interaction = 0.044). CONCLUSION: BPb, BCd, and UCd were positively associated with the risk of DKD among diabetic patients. Furthermore, there were the dose-response relationship and multiplication interaction in the associations of BPb, BCd with DKD.

Association between lead and circulating markers of inflammation among traffic enforcers in Metro Manila, Philippines: the MMDA traffic enforcer's health study.

PURPOSE: Several epidemiological studies have linked lead (Pb) exposure to induced oxidative stress and the promotion of inflammatory response. We performed a within-subjects study (repeated measures study) to evaluate the relationship between the concentration of blood lead (B-Pb) and toenail lead (T-Pb) and circulating markers of inflammation. METHODS: We evaluated the associations between B-Pb concentrations and T-Pb concentrations and circulating markers of inflammation, soluble intracellular adhesion molecule-1 (s-ICAM-1), soluble vascular adhesion molecule-1 (s-VCAM-1), and high-sensitivity C-reactive protein (hs-CRP) on 158 traffic enforcers from the Metropolitan Manila Development Authority (MMDA) traffic enforcer's health study. Linear mixed-effects models with random subject-specific intercepts were fitted to estimate the association between B-Pb and T-Pb exposure and circulating markers of inflammation, adjusting for confounding factors. RESULTS: Traffic enforcers were middle-aged men (89.4%) with a mean age (± SD) of 37.1 years ± 8.9 years and had a total of 293 valid markers of inflammation measurements. B-Pb concentration was related to increased hs-CRP levels. A 10% increase in B-Pb was associated with a 5.7% increase in hs-CRP level [95% confidence interval (95% CI): 1.3-10.1]. However, B-Pb was not associated with s-ICAM-1 and s-VCAM-1. Furthermore, no associations were observed between T-Pb and all the circulating markers of inflammation. CONCLUSIONS: Low-level B-Pb may increase hs-CRP among traffic enforcers. Moreover, the study suggests that Pb via the oxidative and inflammation pathways may have an essential role in the development of cardiovascular disease. Furthermore, MMDA and the Department of Labor and Employment can use our study's findings as evidence to conduct routine screening of blood heavy metals, especially Pb, among MMDA and other traffic enforcers as part of their yearly medical examination.

The Association between Lead Exposure and Dental Caries: A Systematic Review.

INTRODUCTION: Dental caries has declined over the years, but it remains a major public health issue. This review aimed to investigate the association between lead (Pb) and caries experience in either deciduous or permanent teeth. METHODS: A comprehensive search of PubMed, Embase, and Google Scholar was conducted to identify relevant studies published up until December 2022. Included were human observational studies that investigated the association between Pb exposure and dental caries. The review adhered to the PRISMA guideline. RESULTS: Sixteen studies were included in this review, with nine focusing on deciduous teeth, thirteen on permanent teeth, and six examining both types of teeth. Most of the studies (5 of 6) found a positive association between blood lead (PbB) levels and caries in deciduous teeth, while the findings for permanent teeth were less conclusive, with only 3 of 10 studies finding an association. One of the two studies assessing salivary lead levels found a weak association for permanent teeth. All four studies that measured Pb concentration from teeth found a positive association for both deciduous and permanent teeth. CONCLUSION: Many published studies have indicated a positive association between Pb exposure and caries experience in deciduous dentition. Children with elevated PbB level should be considered having higher caries experience. Due to lack of consensus on measurement and examination technique, there remains insufficient evidence to make any definitive conclusions, especially in permanent dentition, and so more studies are warranted.

Creativity in Health Communication to Promote Blood Lead Testing in Children.

Low rates of blood lead level screening among young children persist as a public health issue in the United States, including in Texas where levels remain below the national average. This article describes a multiyear, multipartner initiative aimed at increasing screening rates through a creative, community-informed social media campaign. Interviews with parents, providers, and state health department staff revealed a common perception that lead poisoning was a relic of the past. Using these insights, the team developed humorous social media messaging comparing extinct animals to lead poisoning to capture attention and change attitudes about lead's current relevance. The "#GetLeadCheckedTexas" campaign ran on state health department channels during National Lead Poisoning Prevention Week in October 2020. Colorful graphics depicted extinct creatures like dinosaurs along with their babies, playing on childhood enthusiasm for such animals while evoking protective feelings in parents. Messaging highlighted lead's dangers for young children and encouraged viewers to discuss testing with providers. Website analytics showed the campaign drove substantial increases in page views for lead screening resources, particularly among providers. While originally designed with a parent audience in mind, the campaign seemed to resonate more with providers, likely due to timing during an awareness week and use of official health department channels. The initiative demonstrates the value of creative communications approaches employed in traditional advertising to raise awareness and promote public health priorities. Audience research, thoughtful use of humor, and designing human-focused messaging helped cut through information clutter and drive engagement with an important childhood health issue.

Effect of blood lead levels on periodontitis in American adults: a cross-sectional analysis from the national health and nutrition examination survey.

BACKGROUND: The primary objective of this study was to assess the impact of blood lead levels on the development and progression of periodontitis. METHODS: This study included 8600 participants from the National Nutrition and Health Examination Survey conducted the United States between 2009 and 2014. The exposure variable was the blood lead level, while the outcome variable was periodontitis. To evaluate the relationship between the blood lead level and periodontitis, a multivariate logistic regression model was used. RESULTS: A positive association was observed between blood lead levels and the risk of periodontitis in Model 1 (OR = 7.04, 95% CI = 5.95-8.31). After adjusting for age (continuous), sex, ethnicity, and BMI (continuous) in Model 2, the significant association between blood lead levels and periodontitis risk remained evident (OR = 3.06, 95% CI: 2.54-3.70). Consequently, even after comprehensive adjustment for potential confounding factors in Model 3, the robust association between blood lead levels and periodontitis risk persisted (OR = 2.08, 95% CI = 1.67-2.60). When considering the serum lead concentration as a categorical variable and after adjusting for potential confounders in Model 3, we observed that the odds ratios (ORs) of periodontitis in the T2 (0.94 µg/dL-1.60 µg/dL) and T3 (lead ≥ 1.60 µg/dL) groups increased from 1.27 (OR = 1.27, 95% CI: 1.11-1.44) to 1.57 (OR = 1.57, 95% CI: 1.36-1.81) compared to T1 group. Subgroup analysis revealed no effect modifiers. CONCLUSIONS: Our main findings suggest that there is no safe range of blood lead levels regarding periodontitis risk and that increasing blood lead levels can significantly increase the prevalence of periodontitis.

High-density lipoprotein cholesterol modifies the association between blood lead and uric acid: results from NHANES 2005-2016.

BACKGROUND: The association between blood lead (PbB) and uric acid (SUA) remains unclear in US adults without a high level of lead exposure. Additionally, the effects of high-density lipoprotein cholesterol (HDL-C) modifying this association are still unclear. Therefore, this study aims to assess the effect of modification of high-density lipoprotein cholesterol on the association between PbB and SUA. METHOD: This research analyzed National Health and Nutrition Examination Survey (NHANES) data from 2005 to 2016. Through several screenings, 18,578 participants over the age of 20 were eligible for the analysis. Multivariable linear regression was used to evaluate the association between PbB and SUA. By having stratified participants based on the HDL-C intake category (low HDL-C intake < 50 mg/dl; high HDL-C intake ≥ 50 mg/dl), effect modification by HDL-C was assessed through a likelihood ratio test between PbB and SUA. RESULT: Multivariable linear regression indicated that PbB positively affects SUA (ß = 0.19, 95% CI 0.16-0.22). The relationship between PbB and SUA was different in the low and high HDL-C intake group (ß 0.12 95% Cl 0.08-0.16 vs. ß 0.26 95% Cl 0.22 ~ - 0.30). Furthermore, high-density lipoprotein cholesterol significantly modified the relationship between PbB and SUA in all models which indicates that the interaction of lead exposure and HDL-C is more dangerous than the sum of the individual effects. CONCLUSIONS: Our study shows that high-density lipoprotein cholesterol and blood lead have an interactive effect on increasing uric acid, which may have great importance for clinical medication.

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.

Unraveling the interaction between lead and calcium in occupationally exposed males: an exploratory observation study.

OBJECTIVE: The systemic illnesses associated with chronic lead exposure are partially explained by the interaction between lead and calcium metabolism. Lead exposure is posited to alter calcium levels either by altering calcium homeostasis markers or altering bone remodeling. The present study investigated the interaction between blood lead levels and calcium homeostasis markers and bone remodeling markers among lead-smelting plant workers. METHOD: Adult male workers employed at the lead-smelting plant were clinically investigated as part of their regular occupational health assessment program. Additionally, control participants without occupational lead exposure, employed in administrative and white-collar jobs were invited to participate in the study. Sociodemographic and occupational details were collected by pre-standardized semi-structured questionnaires from all consenting participants, followed by clinical examination and blood collection. Blood lead levels were estimated using microwave-assisted acid digestion and the inductively coupled plasma mass spectrometry technique. Serum calcium and total protein and alkaline phosphatase levels were estimated as per standard biochemical techniques. 25-hydroxy vitamin-D3, calcitriol, and osteocalcin were estimated using the enzyme-linked immunosorbent assay. In addition to comparative analysis for comparing the two groups, independent linear regression models were explored to investigate the associations between serum calcium and blood lead and osteocalcin levels. RESULT: A total of 189 lead-exposed men employed at the lead-smelting plant and 25 male control participants consented to participate. The two groups were similar in age, diet, and body mass index. Occupationally exposed individuals exhibited significantly lower serum calcium and higher bone remodeling markers (osteocalcin and alkaline phosphatase) as compared to controls. However, the serum 25-hydroxy vitamin-D3 and calcitriol levels were not significantly different between the two groups. Lastly, the serum lead and osteocalcin were weakly but significantly associated with serum calcium levels after controlling for variations in total protein, diet, 25-hydroxy vitamin-D3, calcitriol, and alkaline phosphatase in the study participants. CONCLUSION: Current observations reinforce the adverse role of lead exposure on calcium metabolism. Although lead exposure is posited to affect calcium metabolism by multiple pathways, current study observations favor the bone remodeling pathway. The observations recommend periodic screening for calcium and bone health among lead-exposed adults.

Blood lead levels in children residing in a 115-year old urban settlement in Harare, Zimbabwe: a cross sectional study.

BACKGROUND: Elemental lead (Pb) toxicity in children, irreversibly affects their growth and development. We assessed the prevalence of high blood Pb levels (BLL) in children living in a potentially high risk residential area and also assessed Pb levels in environmental specimens. METHODS: This cross sectional study measured blood lead levels (BLL) in 86children living in Mbare, a densely populated suburb in Harare, Zimbabwe, characterised by dwellings progressively constructed from 1907 through to the 1940s, before the ban of leaded paint. Study participants of both genders were under 6 years of age. Potential risk factors of Pb poisoning were assessed. Pb levels were also assessed in soil, water and paint chip specimens from the study area. RESULTS: The mean (standard deviation) BLL was 4.3 ± 0.75 g/dL. Twelve (13.95%) participants had BLL of > 5.0ug/dL. Our results showed no significant association between BLL and household income, participant behaviour/habits/activities, sources of drinking water, and the types of cookware used to prepare meals in their households. CONCLUSION: Mean BLL observed in the current study were higher compared to those of children of similar age groups in the United States, suggesting that Pb contamination may be more ubiquitous in the Mbare flats area, potentially predisposing these children to impaired development.

Children drinking private well water have higher blood lead than those with city water.

Although the Flint, Michigan, water crisis renewed concerns about lead (Pb) in city drinking water, little attention has been paid to Pb in private wells, which provide drinking water for 13% of the US population. This study evaluates the risk of Pb exposure in children in households relying on private wells. It is based on a curated dataset of blood Pb records from 59,483 North Carolina children matched with household water source information. We analyze the dataset for statistical associations between children's blood Pb and household drinking water source. The analysis shows that children in homes relying on private wells have 25% increased odds (95% CI 6.2 to 48%, P < 0.01) of elevated blood Pb, compared with children in houses served by a community water system that is regulated under the Safe Drinking Water Act. This increased Pb exposure is likely a result of corrosion of household plumbing and well components, because homes relying on private wells rarely treat their water to prevent corrosion. In contrast, corrosion control is required in regulated community water systems. These findings highlight the need for targeted outreach to prevent Pb exposure for the 42.5 million Americans depending on private wells for their drinking water.

Using blood lead concentrations of wildlife sentinels to identify environmental risk factors of lead exposure for public health and wildlife rehabilitation efforts.

Lead poisoning remains a persistent health issue for both humans and wildlife, despite strides to reduce lead contamination in the environment. Using Geographic Information Systems (GIS), this study explores the associations between blood lead levels (BLLs) in wildlife sentinels and possible built environment lead exposure risk factors in the Minneapolis-Saint Paul, Minnesota urban area. Results show a high-level of heterogeneity in animal BLLs (n = 472) across our urban environment and suggest that each kilometer increase in road density is associated with a 17.07% (95% CI: 1.48%, 35.05%) increase in BLL in our study species of Virginia opossums and Eastern gray squirrels, and a 14.28% (95% CI: 1.16%, 29.09%) increase in BLL of rock pigeons. For squirrels and opossums, we see an additional 5.72% (95% CI: 0.59%, 10.85%) increased risk of BLL for every 1000 people per square-mile. The relationship between animal sentinels and environmental hazards can give us an insight into the potential lead exposure risks for humans. The use of wildlife sentinel data to explore environmental risk factors supports a One Health approach to better address public health questions and aid in wildlife rehabilitation related to residual lead poisoning from ambient environmental exposures.

Risk assessment of lead exposure in radiology personnel in Menoufia hospitals, Egypt.

Lead shielding is used as a guard against scatter radiation. Lead aprons can emit particulate lead into the occupational environment, resulting in the accumulation of lead dust on the skin and garments of workers. This study aimed to assess the risk of lead exposure among radiologists working in the radiology departments by estimating hair and blood lead levels. A total of 40 radiology personnel (18 wearing aprons and 22 not wearing aprons) with a comparable control group (20 personnel not working in a radiology department) underwent a pre-designed questionnaire with estimation of blood and hair levels. The hair and blood lead levels in radiologists wearing aprons were significantly higher than those of the control group and that of the radiologist not wearing aprons. The lead levels in hair and blood were correlated significantly with the duration of wearing aprons in years and weekly working hours. Health care workers in radiology departments demonstrated high hair and blood levels that were higher among workers wearing aprons than those not wearing protective equipment. Hair lead levels can be detected quickly, cheaply, and non-invasively, and could be a helpful screening test for occupational exposure.

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

OBJECTIVES: We 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 METHODS: We 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. RESULTS: A 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. CONCLUSIONS: Intake 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.

Association of low-level blood lead with plasma homocysteine in US children and adolescents.

Although research in adults has revealed a positive relationship between blood lead levels (BLLs) and homocysteine (Hcy) levels in adults, few studies have investigated this relationship in children and adolescents. We evaluated the relationship between lowlevel blood lead and Hcy levels in US children and adolescents. A total of 8,313 children and adolescents aged 8-19 participated in this study via the National Health and Nutrition Examination Survey 1999-2006. Multivariable linear regression analyses were performed to examine the association between continuous BLLs and Hcy levels. The dose-dependent relationship between continuous BLLs and Hcy levels was analyzed using smooth curve fitting. The average age of participants was 14.1 ± 3.3 years (50.3% male). The mean values of BLLs and Hcy levels were 1.45 µg/dL and 5.77 µmol/L, respectively. In a multivariable adjusted model, an increase in 1.0 µg/dL of BLLs was associated with an elevation of 0.06 µmol/L in Hcy levels (ß = 0.06, 95%CI:0.02-0.10, P = 0.001). A linear relationship between BLLs and Hcy levels was discovered using smooth curve fitting (P non-linearity = 0.464). The relationship between low-level blood lead and Hcy levels was stronger on participants with lower serum folate levels (P for interaction = 0.002). Low BLLs were positively associated with plasma Hcy levels in children and adolescents, which varies depending on the levels of folate, vitamin B, and dietary supplements involved in Hcy metabolism.

Leadcare® II Comparison with Graphite Furnace Atomic Absorption Spectrophotometry for Blood Lead Measurement in Peruvian Highlands.

Peru is one of the countries with the highest lead contamination in the world. Biological monitoring has limitations due to the shortage of laboratories with validated methodologies for the measurement of blood lead, and it is necessary to use alternative methods for its measurement in high-altitude cities. We aimed to compare the blood lead levels (BLL) measured by the LeadCare II (LC) method and Graphite Furnace Atomic Absorption Spectrometry (GF-AAS). We measured the BLL of 108 children from the city of La Oroya. The mean and median BLL for GF-AAS were 10.77 ± 4.18 and 10.44 µg/dL, respectively; for the LC method, the mean was 11.71 ± 4.28 and the median was 11.60 µg/dL. We found a positive linear correlation (Rho = 0.923) between both methods. Notwithstanding, the Wilcoxon test suggests a significant difference between both methods (ρ = 0.000). In addition, the Bland-Altman analysis indicates that there is a positive bias (0.94) in the LC method, and this method tends to overestimate the BLL. Likewise, we performed a generalized linear model to evaluate the influence of age and hemoglobin on BLL. We found that age and hemoglobin had a significant influence on BLL measured by the LC method. Finally, we used two non-parametric linear regression methods (Deming and Passing-Bablok regression) to compare the LC method with the GF-AAS. We found that these methods differ by at least a constant amount, and there would be a proportional difference between both. Although in general there is a positive linear correlation, the results of both methods differ significantly. Therefore, its use in cities located at high altitudes (higher than 2440 m.a.s.l.) would not be recommended.

A Study of Maternal and Umbilical Cord Blood Lead Levels in Pregnant Women.

Lead is a highly toxic element which can cross the placental barrier and enter the fetus during pregnancy. Parental lead exposure has adverse effect on infant as well as on maternal health. As part of our program to investigate the lead poisoning in human population we investigated the maternal blood lead levels (MBLL) and umbilical cord blood lead (UBLL) levels in 200 pregnant women and collected their socio-demographic details. In the study we found high lead levels in both maternal and umbilical cord blood samples. The results showed 47.5% maternal blood (n = 95) detected with lead while 38.5% umbilical cord blood (n = 77) samples had lead concentration higher than that of reference range of ≤ 5 µg/dL. We also found that the Spearman's correlation coefficient (rs) revealed a strong positive correlation between the MBLL and UBLL (rs = 0.63). The results from socio-demographic questionnaire demonstrated that the recent home painting (p = 0.002) and residing close proximity to traffic congestion (p = 0.05) were significantly associated with MBLL. Education, mother age, fuel and water sources were not significantly associated with MBLL. Iron and calcium deficiency along with tiredness, lethargy, abdominal pain were also reported in women having high lead level > 5 µg/dL. Concludingly, on the basis of results obtained it may be stated that we found elevated BLLs in both pregnant women as well as in umbilical cord blood. The prevalence of elevated lead levels in mothers will expose the fetus to lead through placental barriers mobilization and it can have long term adverse effects on the developing fetus. Therefore, it is recommended that screening of blood lead levels be carried out in high-risk women based on their social, occupational, environmental, and individual factors. In addition, stringent regulations on lead-based products are also required from government agencies/authorities to reduce environmental lead burden and toxicity. Moreover, public awareness programs should be organized on hazardous effect of lead.

Association of peripubertal blood lead levels with reproductive hormones and semen parameters in a longitudinal cohort of Russian men.

STUDY QUESTION: Are peripubertal blood lead levels (BLLs) associated with semen parameters and serum reproductive hormones among young Russian men? SUMMARY ANSWER: We observed a suggestion of lower ejaculate volume with higher peripubertal BLL but no associations of BLLs with reproductive hormones measured throughout adolescence or with other sperm parameters measured at adulthood. WHAT IS KNOWN ALREADY: Lead is a known reproductive toxicant and endocrine disruptor. Previous literature has shown associations between high lead exposure and poorer semen quality both in occupationally and environmentally exposed men. However, to our knowledge, no longitudinal studies have explored the association of childhood lead exposure with semen parameters and reproductive hormones in young men. STUDY DESIGN, SIZE, DURATION: The Russian Children's Study is a prospective cohort study that enrolled 516 boys at age 8-9 years in 2003-2005 and followed them annually for 10 years. BLLs were measured at entry and lifestyle and health questionnaires were completed. Reproductive hormones were measured in blood samples collected every 2 years. PARTICIPANTS/MATERIALS, SETTING, METHODS: Among the 516 boys enrolled, 481 had BLLs measured at entry. Of these, 453 had at least one measurement of serum testosterone, follicle stimulating hormone (FSH) or luteinizing hormone (LH) (median = 5 samples per boy) and 223 had semen samples collected ∼10 years after enrolment. Semen assessment included ejaculated volume, sperm concentration, progressive motility and total sperm count, and parameters were categorized using published andrology standards for low semen quality based on sperm count and motility. Linear mixed models were used to examine the associations of log-transformed BLLs (and BLL categories) with reproductive hormones and semen parameters, adjusting for potential confounders. MAIN RESULTS AND THE ROLE OF CHANCE: Among the 223 young men with peripubertal BLLs and at least one semen sample (total samples = 438), the median (interquartile range) BLL was 3 (2, 5) µg/dl and 27% had BLL ≥5 µg/dl. Overall, 49% of the semen samples fell below reference levels for sperm count and/or motility. Men with peripubertal BLL ≥5 µg/dl had significantly lower ejaculated volume than those with BLL <5 µg/dl (mean = 2.42 vs 2.89 ml, P = 0.02), but this difference was attenuated in adjusted models (mean = 2.60 vs 2.83 ml, P = 0.25). No associations were observed between BLL measured at age 8-9 years and reproductive hormone levels or sperm parameters, including sperm concentration, total count, progressive motility and total progressive motile sperm count, or with the probability of having low semen quality based on sperm count/motility. LIMITATIONS, REASONS FOR CAUTION: Only a subset of the original cohort participated in the semen quality portion of the study, although inverse probability weighting was used to account for possible selection bias. BLLs were only measured at a single time in peripuberty, and other exposure time periods, including later or longer-term childhood exposure, may be more predictive of semen quality. The young men were also exposed to other chemical contaminants before and during pubertal development. WIDER IMPLICATIONS OF THE FINDINGS: While semen volume often receives less attention than other sperm parameters, it is an important component of male fertility. Additional prospective studies covering different exposure windows and including other seminal plasma biomarkers are warranted to explore our finding of potentially lower ejaculated volume with higher BLLs and to confirm the lack of associations for other semen parameters among youth exposed to environmental BLLs. STUDY FUNDING/COMPETING INTEREST(S): Funding was provided through grants R01ES0014370 and P30ES000002 from the National Institute of Environmental Health Sciences, grant R82943701 from the U.S. Environmental Protection Agency, and grant 18-15-00202 from the Russian Science Foundation (O.S and Y.D.). All authors report no competing interests. TRIAL REGISTRATION NUMBER: N/A.