Median Blood Lead Levels Research Articles

Investigating Blood Lead Levels and Its Health Effects on Employees of a Petroleum Industry and the Surrounding Residents: A Case Study of Kirkuk City, Iraq.

This study has been aimed to investigate factors associated with elevated blood lead levels (BLLs) across different percentiles in individuals employed in the petroleum industry and residents of Kirkuk City . In addition, to provide evidence-based approaches to mitigate exposure risks and safeguard vulnerable populations. The study involved 357 participants and utilized quantile regression to examine BLL in petroleum industry workers and Kirkuk residents. Median BLLs were higher among workers (17.5 μg/dL) compared to residents in the city (9.9 μg/dL) and suburbs (7.4 μg/dL). Factors such as smoking, outdoor work, and lower education were associated with elevated BLLs, as confirmed by quantile regression. This study found higher BLLs in petroleum workers compared to Kirkuk residents, associated with smoking, outdoor work, and lower education. The results emphasize the need for targeted interventions and policies to mitigate lead exposure risks in this industrial region.

Effects of Blood Lead Levels

Lead exposures among school-age children are a major public health issue. Although the harmful effects of lead exposure during the first years of life are well known, there is not as much understanding of the effects of low levels of lead exposure during later childhood. To review the effects of blood lead levels (BLLs) <10 µg/dL in school-age children and adolescents. We searched Medline, Embase, Global health, CINAHL, Scopus, and Environmental Science Collection databases between January 1, 2000, and May 11, 2023. We included peer-reviewed English-language articles that presented data on the effects of BLLs <10 µg/dL in individuals ages 5 through 18 years. Data on country, population, analytic design, sample size, age, BLLs, outcomes, covariates, and results were extracted. Overall, 115 of 3180 screened articles met the inclusion criteria. The reported mean or median BLL was <5 µg/dL in 98 articles (85%). Of the included articles, 89 (77%) presented some evidence of an association between BLLs <10 µg/dL during school age and detrimental outcomes in a wide range of categories. The strongest evidence of an association was for the outcomes of intelligence quotient and attention-deficit/hyperactivity disorder diagnoses or behaviors. Few articles controlled for BLLs at age <5 years, limiting conclusions about the relation between later BLLs and outcomes. BLLs <10 µg/dL in school-age children and adolescents may be associated with negative outcomes. This review highlights areas that could benefit from additional investigation.

Urinary PYD/Creatinine Ratio Has Negative Correlation to Serum 25(OH)D and Positive Correlation to Chronic Lead Exposure Index

BACKGROUND: The burden of disease due to lead exposure continues to increase. Lead interferes with 25(OH)D hydroxylation and calcium transport, increasing osteoclastic activity and bone resorption. Pyridinoline crosslinks (PYD), as an indicator of bone damage, can be seen earlier compared to imaging changes. Therefore, it is necessary to determine the correlation between serum 25(OH)D levels and the urinary PYD/creatinine ratio in workers exposed to lead, since up to now, there are only limited studies related to it.METHODS: This cross-sectional study involved 104 workers exposed to lead, selected from parents whose children had blood lead levels above 10 µg/dL. Questionnaires and physical examination were performed to obtain characteristic data from subjects. Data regarding blood lead levels, serum 25(OH)D levels, urinary PYD levels, and urinary creatinine levels were also obtained from various laboratory methods.RESULTS: Most subjects (86.5%) had inadequate serum 25(OH)D. Median blood lead levels was 6.3 (1.2-35.5) µg/dL, chronic lead exposure index was 35.3 (1.2-535.8) years µg/dL, serum 25(OH)D levels was 22 (8-52) ng/mL, and urinary PYD/creatinine ratio was 5.3 (3.6-28.1)×10-6. There was a significant negative correlation between serum 25(OH)D levels and urinary PYD/creatinine ratio in workers exposed to lead. There was also a significant positive correlation between chronic lead exposure index and the urinary PYD/creatinine ratio.CONCLUSION: Since urinary PYD/creatinine ratio is correlated with serum chronic lead exposure index and serum 25(OH)D levels, it suggests that pyridinoline might be a potential biomarker to detect bone metabolism disorder due to the chronic lead exposure. Vitamin D adequacy is also an important factor in preventing bone metabolism disorder amidst chronic lead exposure.KEYWORDS: 25(OH)D, bone resorption, pyridinoline, lead, worker

Edetate Disodium–Based Chelation for Patients With a Previous Myocardial Infarction and Diabetes

In 2013, the Trial to Assess Chelation Therapy (TACT) reported that edetate disodium (EDTA)-based chelation significantly reduced cardiovascular disease (CVD) events by 18% in 1708 patients with a prior myocardial infarction (MI). To replicate the finding of TACT in individuals with diabetes and previous MI. A 2 × 2 factorial, double-masked, placebo-controlled, multicenter trial at 88 sites in the US and Canada, involving participants who were 50 years or older, had diabetes, and had experienced an MI at least 6 weeks before recruitment compared the effect of EDTA-based chelation vs placebo infusions on CVD events and compared the effect of high doses of oral multivitamins and minerals with oral placebo. This article reports on the chelation vs placebo infusion comparisons. Eligible participants were randomly assigned to 40 weekly infusions of an EDTA-based chelation solution or matching placebo and to twice daily oral, high-dose multivitamin and mineral supplements or matching placebo for 60 months. This article addresses the chelation study. The primary end point was the composite of all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for unstable angina. Median follow-up was 48 months. Primary comparisons were made from patients who received at least 1 assigned infusion. Of the 959 participants (median age, 67 years [IQR, 60-72 years]; 27% females; 78% White, 10% Black, and 20% Hispanic), 483 received at least 1 chelation infusion and 476 at least 1 placebo infusion. A primary end point event occurred in 172 participants (35.6%) in the chelation group and in 170 (35.7%) in the placebo group (adjusted hazard ratio [HR], 0.93; 95% CI, 0.76-1.16; P = .53). The 5-year primary event cumulative incidence rates were 45.8% for the chelation group and 46.5% for the placebo group. CV death, MI, or stroke events occurred in 89 participants (18.4%) in the chelation group and in 94 (19.7%) in the placebo group (adjusted HR, 0.89; 95% CI, 0.66-1.19). Death from any cause occurred in 84 participants (17.4%) in the chelation group and in 84 (17.6%) in the placebo group (adjusted HR, 0.96; 95% CI, 0.71-1.30). Chelation reduced median blood lead levels from 9.03 μg/L at baseline to 3.46 μg/L at infusion 40 (P < .001). Corresponding levels in the placebo group were 9.3 μg/L and 8.7 μg/L, respectively. Despite effectively reducing blood lead levels, EDTA chelation was not effective in reducing cardiovascular events in stable patients with coronary artery disease who have diabetes and a history of MI. ClinicalTrials.gov Identifier: NCT02733185.

Comparison of sensitivity between blood parameters and a genotoxic biomarker at low blood Pb levels: A population-based study

BackgroundPrevious studies reported that lead (Pb) exposure induced adverse health effects at high exposure concentrations, however, there have been limited data on sensitivity comparisons among different health outcomes at low blood Pb levels. ObjectivesTo compare sensitivity between blood parameters and a genotoxic biomarker among workers exposed to low blood Pb levels (< 20 µg/dl), and to estimate a benchmark dose (BMD). MethodsPb-exposed workers were recruited from a lead-acid storage battery plant. Their blood lead levels (BLLs) were measured. Blood parameters and micronuclei (MN) frequencies were determined. Multivariate linear or Poisson regression was used to analyze relationships between blood parameters or MN frequencies with BLLs. Two BMD software were used to calculate BMD and its 95 % lower confidence limit (BMDL) for BLLs. ResultsThe median BLL for 611 workers was 10.44 µg/dl with the 25th and 75th percentile being 7.37 and 14.62 µg/dl among all participants. There were significantly negative correlations between blood parameters and BLLs. However, MN frequencies correlated positively with BLLs (all P<0.05). Results from the two BMD software revealed that the dichotomous model was superior to the continuous model, and the BMDL for BLL derived from red blood cell (RBC) was 15.11 µg/dl, from hemoglobin (HGB) was 8.50 µg/dl, from mean corpuscular hemoglobin (MCH) was 7.87 µg/dl, from mean corpuscular hemoglobin concentration (MCHC) was 3.98 µg/dl, from mean corpuscular volume (MCV) was 11.44 µg/dl, and from hematocrit (HCT) was 6.65 µg/dl. The conservative BMDL obtained from the MN data was 7.52 µg/dl. ConclusionOur study shows that low dose Pb exposure caused decrease of blood parameters and increase of MN frequencies. The genotoxic biomarker was more sensitive than most blood parameters. BMDLs for BLL derived from MN frequencies and the red blood cell indicators should be considered as new occupational exposure limits. Our results suggest that MN assay can be considered as a part of occupational health examination items.

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.

Evaluating the association between opium abuse, blood lead levels, and the complexity of coronary artery disease.

Opium abuse and exposure to heavy metals elevate the risk of coronary artery disease (CAD). Therefore, we aimed to determine the association between opium abuse and blood lead levels (BLLs) and the CAD complexity. We evaluated patients with acute coronary symptoms who underwent coronary angiography, and those with >50% stenosis in at least one of the coronary arteries were included. Furthermore, Synergy between PCI with Taxus and Cardiac Surgery I (SYNTAX I) score and BLLs were measured. Based on the opium abuse, 95 patients were subdivided into opium (45) and control (50) groups. Differences in demographics and CAD risk factors were insignificant between the two groups. The median BLLs were remarkably higher in the opium group than in controls (36 (35.7) and 20.5 μg/dL (11.45), respectively, p = 0.003). We also revealed no significant differences in SYNTAX score between the two groups (15.0 (9.0) and 17.5 (14.0), respectively, p = 0.28). Additionally, we found no significant correlation between BLLs and the SYNTAX scores (p = 0.277 and r = -0.113). Opium abuse was associated with high BLLs. Neither opium abuse nor high BLLs were correlated with the complexity of CAD. Further studies are warranted to establish better the relationship between opium abuse, BLLs, and CAD.

Association of blood lead level with cognitive performance and general intelligence of urban school children in ten cities of India

BackgroundLead is toxic to children and effects the cognitive development. The primary objective was to assess the association of blood lead level (BLL) with cognitive performance and general intelligence, of urban school going children aged 6–16 years from ten cities of India. Secondary objective was to assess the association of anaemia with cognitive performance and general intelligence. MethodIn this cross-sectional multicentric study, general intelligence was assessed by colored progressive matrices (CPM)/standard progressive matrices (SPM) test, visual-spatial ability through coding, attention and concentration ability through digit span and working memory through arithmetic tests. Blood samples of participants were collected to assess lead levels. Socioeconomic status and anthropometric measures were also collected. ResultsFrom April 2019–February 2020, 2247 participants with equal gender distribution were enrolled from 60 schools. The median (IQR) BLL was 8.8 (4.8, 16.4) μg/dl. We found that BLL was significantly associated with attention and concentration ability and 1 μg/dl increase in BLL decreases the performance by odds of 1.02 (95 % CI 1.01–1.03). Anaemia is found to be associated with ‘borderline or dull normal’ performance for general intelligence [Adjusted Odds Ratio (AOR) = 1.93 (95 % CI 1.53–2.45)], visual-spatial [AOR = 1.35 (95 % CI 1.03–1.76)], attention and concentration [AOR = 1.30 (95 % CI 1.02–1.66)], working memory [AOR = 1.69 (95 % CI 1.34–2.12)] abilities. ConclusionSince increasing BLL decreases cognitive performance and anaemia decreased both cognitive performance and intelligence, attempts must be made to keep BLL as low as possible and prevent exposure in school going children.

Identification of potential food sources affecting blood lead levels and their health hazards (CVD, respiratory diseases, cancer)

Environmental lead exposure is a well-known and significant public health concern. In areas with low lead exposure, comprehensive and detailed research and validation are needed to eliminate the adverse effects of environmental lead exposure. This study aims to understand the possible food pathways of environmental lead exposure by exploring the contribution of food to blood lead and the mediating effect of blood lead in the occurrence of diseases. Similarly, as lead is a heavy metal pollutant with good research foundation, fine analysis of lead in this period can also be a reference for other unknown pollutants. In this cross-sectional study of 1162 peoples, the data are taken from National Health and Nutrition Examination Survey (NANHES) 2015–2016, we grouped the population according to the median blood lead level (0.038 μmol/L) to screen the variables adjusted by the model. we grouped foods by code and used a generalized additive mixed model (GAMM) to study their relationship with blood lead levels, a correlation has been found between egg mixtures (p = 0.007) and legumes (p = 0.041) consumption and blood lead levels. We analyzed how metabolic status, exercise, and macronutrient intake modulate the impact of certain foods on blood lead levels to infer its possible process. To verify whether adverse effects are caused by lead, we explored the mediating effect of blood lead on the relationship between food intake and disease [cardiovascular diseases (CVD), respiratory diseases, cancer], however, no statistically significant mediating effect was found. Overall, environmental lead exposure through food still affects blood lead levels, but it has not led to adverse outcomes in blood, respiratory system, or cancers Under conditions where lead exposure levels were equivalent to those in the study (blood lead levels， mean = 0.052 μmol/L, standard deviation = 0.048 μmol/L, median = 0.038 μmol/L, min = 0.002 μmol/L, max = 0.904 μmol/L, skewness = 6.543, kurtosis = 89.391).

Occupational Lead Exposure Ototoxicity Evaluated With Distortion-Product Otoacoustic Emissions.

To evaluate the extent of hearing loss among pottery workers in Mexico exposed to lead. The authors conducted a cross-sectional study including 315 adult pottery workers. Auditory function was evaluated by air conduction pure-tone audiometry (pure-tone average) and distortion-product otoacoustic emission (DPOAE) levels (amplitude and signal-to-noise ratio). Lead exposure was assessed with a single blood sample test and classified as low, medium, and high according to blood lead tertiles. Logistic regression models were calculated for the association between blood lead levels, pure-tone average, and DPOAE records. Median (25th-75th) blood lead levels were 14 μg/dL (7.5-22.6 μg/dL). The audiometric pattern and DPOAE records were similar across blood lead levels groups in all frequencies, and no statistically significant differences were found. Adjusted logistic regression models showed no increase in the odds for hearing thresholds >25 dB (HL) and DPOAE absence associated with blood lead levels, and no dose-response pattern was observed ( p > 0.05). Given the results from this cross-sectional study, no association was found between blood lead levels and hearing loss assessed with DPOAE. Future longitudinal work should consider chronic lead exposure estimates among underrepresented populations, which can potentially inform safer work practices to minimize the risk of ototoxicity.

Immune Responses to COVID-19 Vaccines in Patients with Chronic Kidney Disease and Lead Exposure.

Literature data regarding the response rate to COVID-19 vaccination in chronic kidney disease (CKD) patients remain inconclusive. Furthermore, studies have reported a relationship between lead exposure and susceptibility to viral infections. This study examined immune responses to COVID-19 vaccines in patients with CKD and lead exposure. Between October and December 2021, 50 lead-exposed CKD patients received two doses of vaccination against COVID-19 at Chang Gung Memorial Hospital. Patients were stratified into two groups based on the median blood lead level (BLL): upper (≥1.30 μg/dL, n = 24) and lower (<1.30 μg/dL, n = 26) 50th percentile. The patients were aged 65.9 ± 11.8 years. CKD stages 1, 2, 3, 4 and 5 accounted for 26.0%, 20.0%, 22.0%, 8.0% and 24.0% of the patients, respectively. Patients in the lower 50th percentile of BLL had a lower proportion of CKD stage 5 than patients in the upper 50th percentile BLL group (p = 0.047). The patients in the lower 50th percentile BLL group also received a higher proportion of messenger RNA vaccines and a lower proportion of adenovirus-vectored vaccines than the patients in the upper 50th percentile BLL group (p = 0.031). Notably, the neutralizing antibody titers were higher in the lower 50th percentile than in the upper 50th percentile BLL group. Furthermore, the circulating levels of granulocyte-colony stimulating factor, interleukin-8, monocyte chemoattractant protein-1 and macrophage inflammatory protein-1α were higher in the upper 50th percentile than in the lower 50th percentile BLL group. Therefore, it was concluded that lead-exposed CKD patients are characterized by an impaired immune response to COVID-19 vaccination with diminished neutralizing antibodies and augmented inflammatory reactions.

Parathyroid hormones in relation to serum cadmium and lead: the NHANES 2003-2006.

The toxic effects of cadmium and lead exposure on parathyroid function have been investigated extensively while the results were conflicting. We aimed to investigate the association of blood cadmium and lead with serum parathyroid hormone (PTH) based on the general population. We analyzed a sample of 9400 adults aged 18years or older from the US National Health and Nutrition Examination Survey 2003-2004 to 2005-2006. We estimated the association using multivariable linear regression analysis by taking cadmium and lead as a continuous or quartile variable. Restricted cubic splines were utilized to explore the non-linear relationship between cadmium or lead and PTH. The median blood cadmium and lead levels were 0.34µg/L and 1.43µg/dL, respectively. Cadmium was significantly associated with PTH when taken as a continuous variable [Odds ratio (OR): 0.97; 95% confidence interval (95% CI): 0.95-0.99] or a quartile variable (fourth vs first quartile, OR: 0.94; 95% CI: 0.91-0.97). Lead was significantly associated with PTH when taken as a continuous variable (OR: 1.04; 95% CI: 1.02-1.07) or a quartile variable (fourth vs first quartile, OR: 1.06; 95% CI: 1.01-1.10). P values for non-linearity were all less than 0.05. The association between cadmium and PTH was not significant in females. Cadmium was negatively associated with PTH, and lead was positively associated with PTH both in a non-linear manner among the general population. However, there was a gender difference in the relationship between cadmium and PTH.

Lead poisoning among asymptomatic individuals with a long-term history of opiate use in Golestan Cohort Study.

Recent reports of lead poisoning suggest that people who use opium may be exposed to high amounts of lead. Here, we investigate the association between opium use and blood lead levels (BLL) in a population-based cohort study. In 2017, we studied a random sample of 410 people who currently (both within the past year and the past month) used opium and 104 who did not from participants of the Golestan Cohort Study in northeast Iran. Participants were stratified by sex and tobacco use history, completed a comprehensive opiate and tobacco use questionnaire and provided blood. BLL was measured by Lead Care® IIBlood Lead Test Kit, validated by inductively coupled plasma triple quadrupole mass spectrometry. BLL was categorized as "<5 µg/dL", "elevated" (5-10 µg/dL), "high" (10-50 µg/dL), and "very high" (above 50 µg/dL). To assess the association between BLL categories and opiate use, route of consumption and weekly use, we used ordered logistic regression models, and report OR (odds ratio) and 95% CI (confidence interval) adjusted for age, sex, place of residence, education, occupation, household fuel type, and tobacco use. In the cohort, participants used only raw (teriak) or refined (shireh) opium, which were smoked (45%, n=184), taken orally (46%, n=189), or both (9%, n=37), for a mean duration of 24.2 (standard deviation: 11.6) years. The median BLL was significantly higher in people who currently used opium (11.4 µg/dL; IQR: 5.2-23.4) compared with those who did not (2.3 µg/dL; IQR: 2.3-4.2), and the highest median BLL was seen in oral use (21.7 µg/dL; IQR: 12.1-34.1). The BLL was <5 µg/dL among 79.8% of people with no opiate use, compared with only 22.7% in those using opium. BLL was elevated in 21.7%, high in 50.5% and very high in 5.1% of people using opium. About 95% of those with oral (180/189) or dual use (35/37) and 55% (102/184) of those who smoked opium had levels of blood lead above 5 µg/dL. The OR for the association between any opium use and each unit of increase in BLL category was 10.5 (95%CI: 5.8-19.1), and oral use of opium was a very strong predictor of increasing BLL category (OR=74.1; 95%CI: 35.1-156.3). This odds ratio was 38.8 (95%CI: 15.9-95.1) for dual use and 4.9 (95%CI: 2.6-9.1) for opium smoking. There was an independent dose-response association between average weekly dose and BLL among people using opium, overall and when stratified by route of use. Our results indicate that regular use of lead-adulterated opium can expose individuals to high levels of lead, which may contribute to mortality and cancer risks associated with long-term opium use.

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.

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.

Lead Levels in a Potters Population and Its Association With the Use of Different Glazes: Cross-Sectional Evaluation of the Approved Pottery Program.

Lead is one of the most harmful toxic metals to humans. In Mexico, though most potters still use a lead-based glazing process, a new lead-free glaze has been introduced to the production of pottery. The Approved Pottery Program (APP) promotes the production of lead-free pottery. As a component of the APP, we aimed to document in this pilot study the blood lead levels (BLLs) of a sample of potters and the association with the type of glaze used. A cross-sectional study was conducted based on information from 46 potters grouped by 26 workshops. We measured general sociodemographic characteristics, capillary BLLs, and the lead levels of the dirt floors of the workshops. The evaluation of associations and comparisons between glaze types was performed based on a regression model clustered by workshop. The median BLL measured was 13.6 μg/dl (IQR: 7.8–20.4 μg/dl), and 70% of the BLLs were greater than 10 μg/dl. Workshop managers presented higher BLLs compared to others working in the same workshop (median of 14.1 μg/dl (IQR: 11.6–25.3 μg/dl) versus 10.1 μg/dl (IQR: 5.2–16.7 μg/dl), respectively). The median BLLs of potters who used lead-free glaze in at least 80% of production were 8.8 μg/dl (95% CI: −17.3 to −0.3 μg/dl) lower than the BLLs of those who used lead-free glaze in less than 30% of production, adjusted by workshop role. Additionally, the lead levels were significantly lower in workshop dirt floors where lead-free glaze was used in at least 80% of the production compared to those that use less than 30% (180 versus 916 mg/kg; p < 0.05). The use of lead-free glaze in the production of pottery was associated with both lower BLLs in potters and lower soil lead levels in the workshop area.

Effects of maternal exposure to lead on secondary sex ratio in Japan: The Japan Environment and Children’s Study

A decline in the proportion of male births (secondary sex ratio, SSR) has been seen in several countries including Japan in recent years. Although previous studies have reported that the SSR is affected by exposure to chemical substances such as dioxins and polychlorinated biphenyls, as well as heavy metals such as methylmercury, the effects of lead exposure on the SSR have been little studied. The aim of this study was to determine the association between maternal lead exposure and SSR. In a large-scale nationwide birth cohort study, maternal blood lead level (BLL) was determined using whole blood from the second or third trimester of pregnancy. The association between SSR and maternal BLL was estimated using multivariable logistic models. Binomial distribution was applied to examine the differences in SSR by dividing the participants into five groups based on BLL. The primary outcome was SSR, and the child sex was obtained from the medical record transcripts. Of 104,062 fetal records, 85,171 were examined for analysis. The median maternal BLL was 5.85 ng/g (5th–95th percentile 3.45–10.6 ng/g). The overall proportion of males among participating infants was 0.512. In logistic regression models adjusted for covariates, the analysis revealed an increased odds ratio for SSR with higher blood lead concentrations [Group 2: adjusted OR 1.082, 95% confidence interval 1.037 to 1.129, Group 3: 1.122, 1.074 to 1.171, Group 4: 1.214, 1.163 to 1.268, Group 5: 1.279, 1.224 to 1.336]. Compared to the general birth probability in Japan, the group with low BLL had a lower SSR and the group with high BLL had a higher SSR. Higher maternal lead exposures during pregnancy were associated with increased SSR. Further investigations including assessment of paternal lead exposure are necessary to understand the association between lead exposure and SSR.

The Blood Lead Levels of Children and the Loss of Ca2+ from Neurons Owing to Lead.

In order to understand current blood lead levels (BLLs), we investigated the BLLs of children in Sichuan Province from 2011 to 2020. We then monitored the treatment effects of calcium in children with high BLLs to assess their treatment status. Finally, we explored the effects of lead on Ca2+ through in-situ experiments. Whole blood samples were used for BLL tests. The BLLs of 76,362 children aged 0–7 years were measured using atomic absorption spectrometry. The median BLL was 35 μg/L (interquartile range: 28–47). The BLLs were significantly higher in boys than in girls (p < 0.001). The BLLs generally decreased annually and increased with age. The overall prevalence of BLLs ≥ 100 μg/L was 1.20%. The children with high BLLs received subsequent check-ups, and the median time required for effective treatment was 18 months. We observed that lead exposure led to a gradual and persistent loss of Ca2+ levels in neurons of mice brain slices, and the effect did not subside immediately even after the lead was removed. China has made rapid progress in pediatric healthcare, but the treatment status remains unsatisfactory. Because lead causes an irreversible loss of Ca2+, there is an urgent need to develop new standardized treatments to reduce the treatment duration.

Screening for blood lead level in reproductive age group individuals in Kathmandu

Introduction: Elevated blood lead level is associated with serious, often irreversible, health consequences. At present, the safe level of blood lead cannot be ascertained since the emerging data indicate the toxic potential to human organ system at a low level that was previously considered safe. Screening for blood lead level is not in regular practice in Nepal. This study is designed to evaluate the prevalence of detectable blood lead level in reproductive age group of Nepalese population that represents the wide local population. Materials and methods: 170 reproductive age group individual (20 to 49 years) attending Samyak diagnostic Pvt Ltd and Alka IVF and fertility centre for regular health checkup were included in this study for blood lead level analysis. The participants were categorized as normal or sub-fertile. Blood lead level was estimated using anodic stripping voltametry. Results: In total study participants, 28.8% of male and 25.8 % of female had BLL ≥3.0 µg/dL. The minimum detectable blood lead level in both male and female was 3.3 µg/dL while the maximum blood lead level was higher in male (15.5 µg/dL) than in female (8.4 µg/dL). The median blood lead level of the sample population was 3.7(4.8 -6.9) µg/dL. There was no significant difference in blood lead level between gender (p=0.108). Conclusion: It is justifiable to screen for blood lead level in the reproductive age group individual in Nepal.

Comparison of knowledge of occupational hazards of lead exposure and blood lead estimation among roadside and organized panel beaters in Enugu metropolis, Nigeria.

Introductionoccupational practices continuously exposes workers to hazards of lead. This study aimed to compare the knowledge of occupational hazards associated with lead exposure, and blood lead estimation among roadside and organized panel beaters in Enugu metropolis, Nigeria.Methodsthis was a cross-sectional study. Multistage sampling method was used to select 428 panel beaters in Enugu metropolis. Samples were analyzed using Atomic Absorption Spectrometer at 283.3 wavelengths. Data were entered and analyzed using Statistical Package for Social Science 20. Comparative analysis were done using chi - square, T-test, Mann-Whitney U-test, Kruskal-Wallis test, logistic regression and level of significance was set at 5%.Resultsthe majority of respondents on both roadside (59.8%) and organized (73.4%) sectors had poor knowledge of hazards of lead exposure. The difference was significant using χ2 (P<0.05). The median blood lead levels were 3.0µg|dl and 16.0µg|dl for roadside and organized panel beaters respectively. The difference was significant with Mann-Whitney U test (P<0.001). The prevalence of elevated blood lead at 10µg|dl were 36.9% (roadside sector) and 64.5% (organized sector). The duration of working hours (OR = 4.34, CI = 1.729 – 10.338) was found to be the predictor of elevated blood lead levels.Conclusionthere were general poor knowledge of hazards of lead exposure and high prevalence of elevated lead levels which were more among organized panel beaters. Advocacy on standard organizational structures that support improved occupational health practices is needed and routine outreach by research institutions for health education and safety training.