Relationship between personal-sampled air lead and blood lead in low-lead-exposure workers in Japan to apply multiple regression models determining permissible air lead concentration.

OBJECTIVES: We investigated the relationship between lead in air (Pb-A) measured by personal sampling and blood lead (Pb-B) in workers with relatively low lead exposure to estimate the permissible air concentration of lead corresponding to the biological tolerance value of Pb-B of 15 µg/dL. METHODS: We collected air samples at a lead-acid battery factory in Japan by personal sampling devices attached to 32 workers (19 males and 13 females) and measured Pb-A by a graphite furnace atomic absorption spectrophotometer in 2017-2020. In addition, we collected information on age, smoking habits, Pb-B, and urinary δ-aminolevulinic acid from the records of medical examinations for lead poisoning. Samples were collected two times from four workers, resulting in 36 data sets. RESULTS: Before analyses, we excluded four inappropriate data sets. The levels of Pb-A in the factory and Pb-B in the workers were almost under the current permissible limits. Multiple regression models showed significant correlations between Pb-B and Pb-A, and sex, and borderline significance between Pb-B and age. Based on them, we calculated Pb-A corresponding to Pb-B 15 µg/dL, and obtained similar values to the current occupational exposure limit (OEL) of 30 µg/m3 , with slight variation between sex and age. CONCLUSION: These results validate OEL, although supplementary conditions in terms of sex and age may be necessary.

Reassessment of the threshold of the blood lead level to increase urinary δ-aminolevulinic acid based on their relationship in recent lead workers in Japan.

OBJECTIVES: The present study investigated the quantitative relationship between blood lead (Pb-B) and urinary δ⁻aminolevulinic acid (ALA-U) in lead workers, and examined the Pb-B level that induces increases in ALA-U and the corresponding ALA-U. METHODS: We collected 10 562 data sets on Pb-B, ALA-U, age, and smoking habits from 808 workers (771 males and 37 females) who underwent multiple lead poisoning medical examinations at a lead-acid battery and lead smelting plant in Japan between 1995 and 2018. Females were excluded, and data collected in 169 subjects prior to engaging in lead work were used as the control. Pb-B and ALA-U levels were measured by graphite furnace atomic absorption spectrophotometry and high-performance liquid chromatography respectively. RESULTS: A significant dose-response relationship was observed between Pb-B and ALA-U based on Pb-B-classified observations of increases in ALA-U values and the prevalence of over-reference ALA-U as well as regression analyses independent of smoking habits. The results obtained revealed that the threshold of Pb-B to increase ALA-U was 25.1-35.0 µg/dL based on the significant elevation point of the prevalence of over-reference ALA-U and 16.2-22.3 µg/dL from a 3rd degree regression equation. CONCLUSIONS: We proposed a threshold of Pb-B to increase ALA-U of 20 µg/dL and a biologically acceptable value of ALA-U of 1 mg/L, corresponding to the threshold.

Influence of VDR and HFE polymorphisms on blood lead levels of occupationally exposed workers.

Lead is a ubiquitous heavy metal toxin of significant public health concern. Every individual varies in their response to lead's toxic effects due to underlying genetic variations in lead metabolizing enzymes or proteins distributed in the population. Earlier studies, including our lab, have attributed the influence of ALAD (δ-Aminolevulinate dehydratase) polymorphism on blood lead retention and ALAD activity. The present study aimed to investigate the influence of VDR (Vitamin D receptor) and HFE (Hemochromatosis) polymorphisms in modulating blood lead levels (BLLs) of occupationally exposed workers. 164 lead-exposed subjects involved in lead alloy manufacturing and battery breaking and recycling processes and 160 unexposed controls with BLLs below 10 µg/dL recruited in the study. Blood lead levels, along with a battery of biochemical assays and genotyping, were performed. Regression analysis revealed a negative influence of BLLs on ALAD activity (p < 0.0001) and a positive influence on smokeless tobacco use (p < 0.001) in lead-exposed subjects. A predicted haplotype of the three VDR polymorphisms computed from genotyping data revealed that T-A-A haplotype increased the BLLs by 0.93 units (p ≤ 0.05) and C-C-A haplotype decreased the BLLs by 7.25 units (p ≤ 0.05). Further analysis revealed that the wild-type CC genotype of HFE H63D presented a higher median BLL, indicating that variant C allele may have a role in increasing the concentration of lead. Hence, the polymorphism of genes associated with lead metabolism might aid in predicting genetic predisposition to lead and its associated effects.

A Rapid Mercury Droplet Electrode Polarography Method for Determination of Blood Lead Level in Lead Poisoned People.

BACKGROUND: Lead is a hazardous heavy metal, which causes many problems in the human body. Unfortunately, recent reports showed that smugglers and opium sellers add lead to drugs during the production procedure in order to increase its weight and cost. PURPOSE: The aim of this study was development of a rapid and accurate method for measurement of blood lead levels (BLL) in the oral and inhaled opiate abuser people. METHODS: BLL in samples obtained from the oral and inhaled opium addicted patients referring to Sina Hospital in Tabriz, Iran, during 2017 was compared with healthy control group (N=15). The wet digestion method was used to prepare whole blood and Mercury Droplet Electrode Polarography (MDEP) method was utilized for measurement of the lead content of digested samples. RESULTS: Results showed that there were significant differences between the BLL of samples obtained from oral (17.12±74.61 µg/dL, p<0.0003) and inhaled (19.33±2.257 µg/dL, p<0.0001) opium addicted groups in comparison with healthy control group (4.669±0.3367 µg/dL). CONCLUSION: Based on the results of this study it was observed that BLL in opium addicted people needs to be measured as soon as possible. Furthermore, screening of blood lead concentrations in opium-addicted people with a rapid and accurate MDEP method is very necessary and important.

Lead poisoning associated with illicit opium use.

Lead poisoning is an uncommon and challenging diagnosis to make. In 2018, The Victorian Department of Health issued a health warning following four cases of lead poisoning associated with illicit opium use in Melbourne, Australia. We present these cases to highlight clinical features and the relevant investigations leading to diagnosis. All cases occurred in recent immigrants to Australia, who had access to non-traditional sources of opioids. Health care professionals should consider lead poisoning in patients with appropriate symptoms and a history of illicit opium use.

Zhiqi Granules Decreased Lead Level but Increased Iron Level in Serum of Chinese Children with Moderately Elevated Blood Lead Levels.

To observe and compare the effects of healthy instruction and Zhiqi granules on lead, calcium, iron, and zinc levels in serum of children with moderately elevated blood lead levels (BLLs). At the same time, the possible mechanisms were discussed. A total of 60 eligible boys aged 4-6 years were selected and divided into two groups (the healthy instruction group and the Zhiqi group) randomly. The boys in the healthy instruction group only received the healthy instruction. Besides the healthy instruction, the boys in the Zhiqi group received 2 g Zhiqi granules orally one time daily. The study lasted for 4 weeks. BLL and serum iron, zinc, and calcium levels of the subjects in the two groups before and after interventions were measured and compared. After the interventions, the BLL in the Zhiqi group lowered significantly, but the decrease of the BLL in the healthy instruction group is not significant, and there was a significant difference in the BLL between the two groups. When the trial was completed, the serum iron level in the Zhiqi group increased significantly, but that in the healthy instruction group changed slightly, and a significant difference was seen between the two groups. There were no significant differences in both serum Ca and Zn levels in these two groups before and after the interventions. Meanwhile, there were no significant differences in serum Ca and Zn levels between the two groups after the interventions. The results suggested that daily intake of Zhiqi granules for 4 weeks together with healthy instruction resulted in a decrease of the BLL and an elevation of the serum iron level.

Occupational health hazards on workers exposure to lead (Pb): A genotoxicity analysis.

BACKGROUND: The present investigation of genotoxicity of lead (Pb) among workers exposed to inorganic Pb environment, which appears to be first of its kind in South India, was undertaken to assess the seriousness, the ill effects of health contributed by this serious environmental pollutant. METHODS: A total of 144 samples comprising of exposed (n=72), and control (n=72) subjects were screened. Demographic data and their associated health levels were undertaken by means of a questionnaire. The blood samples collected were subjected to chromosomal analysis, micronuclei assessment and comet assay. RESULTS: A higher level of Pb was quantified in the blood samples of all exposed subjects. An overview of the genotoxic assessment helped us understand parameters such as age do not affect or bring about any difference in the genotoxic potential of the exposed and control subjects. The only signification feature that resulted in an enhanced genotoxic potential was the years of exposure to the Pb environment that accumulated the dosage of Pb over the years. CONCLUSION: The high positivity of genotoxic potential of Pb in a country like India highlights the need for labelling hazardous metals in paint containers as a means to assure strict regulations.

Lead Poisoning in Children.

Asymptomatic lead poisoning has become more common in children. Blood lead levels of less than 5 µg per dL are associated with impairments in neurocognitive and behavioral development that are irreversible. Risk factors for lead poisoning include age younger than five years, low socioeconomic status, living in housing built before 1978, and use of imported food, medicines, and pottery. The U.S. Preventive Services Task Force released a recommendation in 2019 citing insufficient evidence to assess the balance of benefits and harms of universal screening for elevated blood lead levels in asymptomatic children and pregnant women. Local risk factors can be substantial, and the Centers for Disease Control and Prevention (CDC) recommends that states and cities formulate their own targeted screening guidelines. In the absence of local guidance, the CDC recommends screening all Medicaid-eligible children at 12 months and again at 24 months, or at least once between 36 and 72 months if not previously screened. The CDC also recommends universal screening in areas where more than 27% of the housing was built before 1950, or where at least 12% of children 12 to 36 months of age have blood lead levels greater than 10 µg per dL. Life-threatening lead levels are treated with chelation therapy, and lower levels should prompt case management and environmental investigations to identify and remove the source of exposure. Primary prevention strategies are essential to eliminate the harmful effects of lead on child development.

Standardizing Clinical Response to Results of Lead Screening: A Quality Improvement Study.

BACKGROUND AND OBJECTIVES: Lead exposure remains common and is associated with adverse intellectual and behavioral outcomes. Despite quality improvement used to increase screening rates, clinical response to elevated lead levels remains variable. Our aim was to increase provider adherence to published guidelines for addressing elevated lead levels. METHODS: We created a protocol for addressing elevated lead levels on the basis of published guidelines. The protocol included ordering multivitamins with iron and follow-up lead testing, educating families about identifying and reducing sources of lead exposure, and referring to a specialty environmental health clinic when indicated. We used quality improvement methods to increase provider adherence to the protocol in a large, academic primary care center among patients 9 to 27 months old. The outcome measure was the percentage of elevated lead levels for which providers adhered to all elements of the protocol. This measure was plotted on a control chart. Statistical process control was used to determine a significant change to system performance. RESULTS: Adherence to the protocol rose from 5% to 90%. Key interventions included decision support in the e-health records and weekly review of reports of lead levels. These interventions were supported by staffing adjustments and individualized feedback to create accountability. CONCLUSIONS: Simple process changes dramatically improved adherence to complex guidelines for addressing lead exposure in primary care. These changes could be used to similarly standardize clinical responses to other screens.

The effects of occupational lead exposure on selected inflammatory biomarkers.

In exposure to toxic metals such as lead, determining lead and cytokine levels (IL-6, IL-10, and TNF-α) is essential for early detection of diseases. The aim of this study was to develop an model for early detection of inflammation and onset of atherosclerosis in the absence of clinical findings in young workers, which could help physicians take timely an action and start treatment. This study included 49 metal workers exposed to lead occupationally and 50 unexposed administrative workers (controls) who underwent immunological analysis for cytokines (IL-6, IL-10, and TNF-α) and atherosclerosis markers (h-FABP and VCAM-1), toxicological analysis for lead, and routine biochemical analysis (ALT, AST, creatinine) at the Ankara Occupational and Environmental Diseases Hospital in 2017. Lead levels correlated with IL-6, IL-10, and TNF-α (r=0.469, r=0.521 and r=0.279, respectively, p<0.01) but did not significantly affect h-FABP and VCAM-1 levels.

ECG conduction disturbances and ryanodine receptor expression levels in occupational lead exposure workers.

OBJECTIVES: A significant number of researches have evidenced that occupational lead (Pb) exposure increased risks of cardiovascular disease. However, evidences about the potential effects of Pb on the cardiac conduction system are sparse and inconclusive. Besides, ryanodine receptors (RyRs) induced dysfunction of cardiac excitation contraction coupling which is considered to be one of the mechanisms in cardiovascular diseases. Therefore, we examined the association between occupational Pb exposure and ECG conduction abnormalities, as well as RyRs in Pb-induced ECG abnormalities. METHODS: We investigated 529 Pb smelter workers, and measured blood lead (BPb), zinc protoporphyrin (ZPP), ECG outcomes and RyR expression levels. Based on BPb levels, the workers were divided into three groups: the BPb not elevated group, the BPb elevated group and the Pb poisoning group. Descriptive and multivariable analyses were performed. RESULTS: Compared with the BPb not elevated group, the Pb poisoning group had a higher incidence of high QRS voltage, and a lower level of RyR1 gene expression (p<0.05). Further unconditional multivariable logistic regression analyses showed that high QRS voltage was positively related to BPb (OR=1.045, 95% CI 1.014 to 1.078) and inversely associated with RyR1 expression (OR=0.042, 95% CI 0.002 to 0.980) after adjusting for potential confounders. In addition, multiple linear regression analyses showed that the QTc interval was positively associated with ZPP (ß=0.299, 95% CI 0.130 to 0.468) after adjusting for potential confounders. CONCLUSIONS: Our study provided evidences that occupational exposure to Pb may be associated with worse ECG outcomes (high QRS voltage), which might be related to decreased levels of RyR1.

Relations between the blood lead level and metabolic syndrome risk factors.

OBJECTIVE: This study is to examine the relations between the blood lead level, which has an effect on lipid metabolism in the body, and metabolic syndrome to establish a basic reference for the development of a local community health management program. DESIGN AND SAMPLE: This study is a descriptive correlational study about verifying the relation between the blood lead level and metabolic syndrome risk factors. A total of 2,833 respondents' data were sampled on the 1st year (2016) data of the 7th Korea National Health and Nutrition Examination Survey conducted by the Korean Centers for Disease Control and Prevention (CDC). MEASURES: The data were analyzed to explore blood lead level differences by demographic characteristics, correlations between the blood lead level and metabolic syndrome risk factors using chi-square test, Mann-Whitney U-test, Pearson correlation coefficient, and binary logistic regression. RESULTS: Systolic and diastolic blood pressure, triglycerides (TG), and FBS demonstrated a significant difference by blood lead level (p < 0.001). Systolic and diastolic blood pressure, waist circumference, and FBS and TG levels were positively correlated with blood lead level (p < 0.005), whereas high-density lipoprotein cholesterol was negatively correlated (r = -0.038, p < 0.005). CONCLUSION: This study confirmed that the blood lead level was significantly correlated with all metabolic syndrome variables.

Evaluation of the Blood Lead Screening Component of the Southern Nevada Childhood Lead Poisoning Prevention Program.

CONTEXT: While public health programs and policies have worked to reduce lead exposure, lead poisoning remains a major preventable public health concern in the United States. OBJECTIVE: In Clark County, Nevada, blood lead level (BLL) screening has historically been sparse. Thus, the purpose of this study was to evaluate the impact of the Southern Nevada Childhood Lead Poisoning & Prevention Program (CLPPP) in increasing screening efforts and identifying children with elevated blood lead levels (EBLLs). MAIN OUTCOMES: The proportion of children screened after the implementation of the CLPPP and the number of children identified with detectable BLLs. RESULTS: A total of 43 028 BLL results for children younger than 6 years were assessed from 2006 to 2011. More than 19% of children tested during the project period had a detectable BLL. The number of BLL tests for children younger than 6 years increased from 4180 in 2005-2006 to 9304 in just the second year of CLPPP implementation. Once the initial implementation grant was over and additional funding was unavailable, the BLL screening once again declined to 5541 in 2016-2017. CONCLUSION: Evaluation of CLPPP activities suggests that outreach and education efforts, funded by the Centers for Disease Control and Prevention, played a significant role in increasing blood lead screening in Southern Nevada. However, despite these efforts, less than 5% of all children younger than 6 years were screened, which has declined further after the end of federal support.

Impact of chronic lead exposure on liver and kidney function and haematologic parameters.

BACKGROUND: Lead, one of the most widely used metals because of its beneficial physical properties, has been reported to adversely influence several different organs and organ systems. The aim of the present study was to examine the effect of lead exposure on liver and renal function and haematologic parameters. METHODS: This was a case-cohort study comparing adults with occupational, environmental or opium-related lead exposure with blood lead levels [BLL] >10 µg/dL (High blood lead level (HBLL) group and age- and gender-matched normal healthy individuals (Low blood lead level [LBLL] group with BLL <10 µg/dL). The complete blood count and concentrations of serum creatinine, urea, aspartate aminotransferase (AST), alanine aminotransferase (ALT) were recorded for subsequent investigation. RESULTS: The mean BLL was significantly higher in the HBLL than in the LBLL groups (51.36 ± 44.72 vs 4.17 ± 1.97 µg/dL). The Spearman's rho revealed a significant association between BLL and urea (r = 0.25, P < 0.001), creatinine (r = 0.16, P = 0.02), AST (r = 0.42, P < 0.001) and ALT (r = 0.27, P < 0.001). The median [IQR] serum urea (34 mg/dL [27-221]) vs (30 [27-36]), creatinine (0.9 mg/dL [0.8-1]) vs (0.8 [0.7-0.9]), ALT (25 mg/dL [16-49]) vs (22 [16-30]) and AST concentrations (29 mg/dL [20-42]) vs (20 [18-24]) were all significantly higher (P < 0.05) in the HBLL group compared to the LBLL group. The median [IQR] haemoglobin (12.6 g/dL [10.4-15.4]) vs (15.2 [14.6-16.3] and haematocrit (36.9% [31-44.8]) vs (45.6 [43.6-48.2]) were both significantly lower (P < 0.001) in the HBLL group than in the LBLL group. CONCLUSION: The results indicated that people with chronic lead exposure with BLLs greater than 10 µg/dL are at risk of renal, liver and haematologic impairments.