Occupational Lead Research Articles

Blood pressure and renal function responses in workers exposed to lead for up to six years

Abstract Background Lead is a widespread environmental toxicant. However, there is currently no consensus whether low-level lead exposure raises blood pressure (BP) or induces kidney dysfunction. Purpose The Study for Promotion of Health in Recycling Lead (SPHERL) assessed the BP and renal function (RF) responses for up to six years in the workers without previous occupational lead exposure. Methods BP was the average of 5 consecutive readings and the estimated glomerular filtration rate was derived from serum creatinine (eGFRcrt) and cystatin C (eGFRcys). Blood lead (BL) was measured by inductively coupled plasma mass spectrometry (detection limit 0.5 mg/dL). The statistical methods included multivariable-adjusted mixed models and interval-censored Cox regression analysis. Results The 234 workers analyzed were on average 28.5 years old and included 91.9% men. The baseline BL concentration was 4.35 µg/dL and increased 3.17-fold over follow-up (median: 2.03 years; range: 0.92-6.45 years). The changes in BP and RF were not significantly correlated with the follow-up-to-baseline BL ratio (p≥0.51 and p≥0.18, respectively). The fully-adjusted changes in systolic/diastolic BP associated with a doubling of BL were -0.25/-0.12 mm Hg (CI: -0.94 to 0.44/-0.66 to 0.42 mm Hg). Accordingly, the incidence of stage-1 or -2 hypertension was not associated with the BL change (p≥0.063). Similarly, the changes in eGFRcrt and eGFRcys associated with a 3-fold BL increment were not significant, amounting to -0.70 mL/min/1.73 m2(CI: -1.70 to 0.30 mL/min/1.73 m2) and -1.06 ml/min/1.73 m2 (-2.16 to 0.03 mL/min/1.73 m2). Conclusion The BP and RF responses to an over 3-fold BL increment were small and not significant confirming the safety of modern lead-handing facilities operating under current safety rules.Figure 1Figure 2

Impact of occupational lead exposure on the comprehensive health status of gas cutter workers

BackgroundOccupational exposure to hazardous substances, particularly in involving metal cutting and welding industries, poses critical public health concern. This study assesses the health status of gas cutter workers, focusing on Pb exposure. MethodIn this cross-sectional study, 40 participants with BLL ≥20 μg/dL were recruited from workers engaged in oxy-acetylene metal cutting. These workers were compared to an age-, sex-, and sociodemographic-matched control group (n = 42) from the same workplace. Health assessments including routine clinical and laboratory investigations along with BLL, and markers of calcium homeostasis were carried out. ResultsGas cutters exhibited significantly higher mean systolic BP and elevated SGOT levels, with similar prevalence of respiratory symptoms and musculoskeletal disorders in both groups. No significant differences were found in most hematological, liver, and renal parameters. However, gas cutters had significantly higher PTH levels and lower serum vitamin D levels. Pulmonary function tests indicated significantly reduced FVC, FEV1, FEV1/FVC ratio, FEF25-75 %, and PEFR in gas cutters, as well as markedly higher CRP levels. ConclusionGas cutters experience significant health impacts compared to controls, including elevated systolic BP, impaired pulmonary function, and disturbance in calcium homeostasis due to occupational Pb exposure. Higher CRP levels suggest notable inflammatory responses. These findings highlight the urgent need for targeted interventions and regular monitoring to mitigate health risks associated with Pb exposure among gas cutter workers.

Assessment of immune status markers during occupational lead exposure

The immune system is sensitive to the effects of environmental factors, and according to numerous studies, lead has an immunotoxic effect. At the same time, there is evidence of the multidirectional nature of the impact of lead on the immune system, determined by the degree of exposure to this heavy metal, which makes it current to study changes in immunological markers in workers of a modern lead recycling plant, taking into account levels and complexity of exposure. In the era of personalized medicine, monitoring the potential influence of occupational factors exposure on the immune system can facilitate a personalized approach to the prevention of work-related health conditions. The aim of the study: to evaluate changes in immune status markers among employees of lead recycling plant. The main group – 62 men working at a lead recycling plant, the control group – 47 men not exposed to occupational factors. Laboratory examination included a determination of the lead blood level, a clinical blood test, the serum levels of IL- 1â, IL- 10, IL- 8, MCP-1, C3 and C4 complement components, IgA, IgM, IgG. In the main group, compared to the control group, a higher number of neutrophils, lymphocytes, monocytes, higher levels of IL-8, C3 and C4 components of the complement system, and lower levels of IgM were detected. In the main group, the following changes in markers were significantly more often detected in comparison with reference values: an increase in the C3 component of complement (51.6% in the main group compared to 12.5% in the control group), decreased IgG (24.2% compared to 6.2%) and increased IgA (22.6% compared to 6.2%). Associations were identified between the lead blood level and the number of lymphocytes, the level of IgG, between work experience in contact with lead and the level of MCP-1 and C3 complement components. The results of the studies revealed the presence of changes in the immune status markers of workers at a lead recycling plant, which demonstrate a proinflammatory effect of lead and an influence on the humoral immune status. The identified changes in immunological parameters may underlie the mechanisms of formation of pathological conditions associated with lead exposure, which determines the relevance of continuing research to assess dynamic changes in immunological parameters and develop a system for monitoring the immune status of workers exposed to lead and its compounds to optimize preventive measures.

Assessment of occupational exposure to lead among workers engaged in a city bus garage in Addis Ababa, Ethiopia: a comparative cross-sectional study

BackgroundLead is one of the most nonessential toxic heavy metal agents found in automotive garages. The occupational exposure of garage workers to lead commonly poses acute and chronic health risks that can be prevented. In Ethiopia, there have been limited studies on lead exposure among garage workers, who overemphasize exposure to lead. This study aimed to assess occupational blood lead levels and associated factors in garage workers using a cross-sectional comparative design.MethodsA comparative cross-sectional study design was used to compare the occupational blood lead levels of 36 randomly selected garage workers and 34 office workers who were matched by age and sex. Blood specimens were collected by trained medical laboratory experts. The collected blood samples were tested in a certified laboratory using a microwave plasma atomic emission spectrometry (MP-AES) device at a wavelength of 405.78 nm. Excel and SPSS Version 26 were used for data management and analysis, respectively.ResultsThe mean (SD) age of the exposed group was 39.0 (7.5) years, whereas the mean age of the unexposed group was 38.0 (6.1) years. The occupational mean (SD) blood-lead-level in the exposed groups was 29.7 (12.2) µg/dl, compared to 14.8 (9.9) µg/dl among the unexposed groups. The mean blood-lead level among the exposed workers was significantly different from that among the unexposed workers (P < 0.01). Of all the study participants, only 22.2% of the exposed groups had blood lead levels higher than the World Health Organization’s recommended limit of 40 µg/dl. The main significant predictors of occupational blood-lead-level exposure among workers were extra working hours, service years, and having a previous (prior) employment history in a garage. The occupations of the two groups did not significantly differ in terms of blood-lead levels (p > 0.05).ConclusionsThe BLL of the Garage workers was significantly greater than that of the Non-Garage workers. Hence, it is advised that garage management should encourage workers to use exposure prevention methods, such as washing their hands before eating and taking showers after the completion of work, by providing regular occupational safety training.

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.

Amyotrophic Lateral Sclerosis Survival and Occupational Lead Exposure in the Danish National Patient Registry (P2-15.002)

Amyotrophic Lateral Sclerosis Survival and Occupational Lead Exposure in the Danish National Patient Registry (P2-15.002)

Maternal blood lead level and its impact on cord blood hematological parameters

Introduction. More than 13 annual million deaths are caused by environmental pollutants worldwide. Urbanization, population growth, industrialization and globalization affect our lives both positively and negatively. Women can become lead exposed through occupational and environmental sources. Once lead enters the body, it is mainly deposited in diverse organs: brain, kidneys, liver and bones. The body stores lead mainly in the bones, where it accumulates over time that may be further released into the bloodstream during pregnancy, thus posing a threat to growing fetus. Aim: to examine a lead impact on newborn hematological parameters during perinatal period. Materials and Methods. A retrospective cohort study with 306 pregnant women and paired newborns was carried out. Peripheral blood lead level (BLL) in pregnant and postpartum women was analyzed by using the atomic-absorption spectrophotometry method. Blood specimens were collected for analysis in the third trimester of pregnancy. Newborns hemoglobin concentration (mean corpuscular hemoglobin concentration, MCHC) in erythrocytes was also assessed. Results. We have detected a statistically significant decrease of MCHC in babies born to mothers with BLL &gt; 0.24 µmol/L vs. BLL &lt; 0.24 µmol/L. This difference may indicate a decline in hemoglobin fetal production caused by lead intoxication. Conclusion. Study corroborates an idea that pregnant women with occupational or environmental lead exposure should be monitored for BLL, which should not exceed 0.24 µmol/L during pregnancy.

The role of laboratory diagnostics in the assessment of occupational lead exposure

Introduction: Industrialization and urbanization led to a significant increase in the environment. Lead inhibits the activity of numerous enzymes, triggers oxidative stress, and causes protein biosynthesis dysregulation. Inhalation of lead particles is the most common route of intoxication associated with occupational exposure. This study aims to evaluate laboratory methods and biomarkers in the assessment of lead exposure. Methods: For non-experimental qualitative research, available scientific articles in English published in the relevant databases (MEDLINE and ScienceDirect) were used. The database search was performed using the keywords “Laboratory diagnostics”, “occupational exposure”, and “lead”. Results: Atomic absorption spectrometry (AAS) is the gold standard in laboratory monitoring of occupational lead exposure. Inductively coupled plasma with mass spectrometry is a commonly used method described as more sensitive than AAS due to its low detection limit. Lead concentrations can be determined in various samples, but blood and urine are the most commonly used in laboratory practice. The most important exposure biomarker is the enzyme δ-aminolevulinic acid dehydratase (ALAD) in the blood, which is characterized by progressive inactivation by lead and a negative correlation with its concentration. The concentration of urinary delta-aminolevulinic acid (δ-ALA-U) reflects the state of impaired enzyme function in heme biosynthesis. In addition, determining blood zinc protoporphyrin and urinary coproporphyrin levels significantly aids in assessing occupational lead exposure disorders. Conclusion: The availability of the laboratory methods used and the biomarker specificity and sensitivity play an important role in the adequacy of lead exposure monitoring. Accurate determination of ALAD and δ-ALA-U concentrations, along with other biomarkers, is critical for assessing individuals exposed to lead.

Blood pressure and renal function responses in workers exposed to lead for up to six years.

The Study for Promotion of Health in Recycling Lead (SPHERL) assessed the blood pressure (BP) and renal function (RF) responses for up to 6 years in the workers without previous occupational lead exposure. BP was the average of five consecutive readings and the estimated glomerular filtration rate was derived from serum creatinine (eGFRcrt) and cystatin C (eGFRcys). Blood lead (BL) was measured by inductively coupled plasma mass spectrometry (detection limit 0.5 μg/dL). The statistical methods included multivariable-adjusted mixed models and interval-censored Cox regression analysis. The 234 workers analyzed were on average 28.5 years old and included 91.9% men. The baseline BL concentration was 4.35 μg/dL and increased 3.17-fold over follow-up (median: 2.03 years; range: 0.92-6.45 years). The changes in BP and RF were not significantly correlated with the follow-up-to-baseline BL ratio (p ≥ .51 and p ≥ .18, respectively). The fully-adjusted changes in systolic/diastolic BP associated with a doubling of BL were -0.25/-0.12mm Hg (CI: -0.94 to 0.44/-0.66 to 0.42mm Hg). Accordingly, the incidence of stage-1 or -2 hypertension was not associated with the BL change (p ≥ .063). Similarly, the changes in eGFRcrt and eGFRcys associated with a 3-fold BL increment were not significant, amounting to -0.70mL/min/1.73 m2 (CI: -1.70 to 0.30mL/min/1.73 m2 ) and -1.06mL/min/1.73 m2 (-2.16 to 0.03mL/min/1.73 m2 ). In conclusion, the BP and RF responses to an over 3-fold BL increment were small and not significant confirming the safety of modern lead-handing facilities operating under current safety rules.

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

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. 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. 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. 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.

Relationship and Accuracy of Urine Lead as an Alternative to Blood Lead Biomarker among Panel Beaters in Enugu Metropolis: Nigeria.

The limited alternatives to blood lead biomarkers continue to affect the control of occupational lead exposures. This study assessed the relationship and accuracy of urine lead biomarker as an alternative to blood lead biomarker among roadside and organized panel beaters in Enugu metropolis, Nigeria. This was a cross-sectional analytical study of 428 panel beaters in Enugu metropolis. Samples collected were analyzed using Atomic Absorption Spectrometer (AAS) at 283.3 nm wavelengths. Data were analyzed using correlation and receiver operating characteristics (ROC). A linear positive relationship with high accuracy and sensitivity were found between blood and urine biomarkers. Urine biomarker has a linear relationship with blood biomarker and showed a significant accuracy for the measurement of occupational lead exposure. Therefore, a urinary biomarker can serve as an alternative replacement to blood lead in occupational health practice.

Amyotrophic lateral sclerosis survival and occupational lead exposure in the Danish National Patient Registry

Amyotrophic lateral sclerosis survival and occupational lead exposure in the Danish National Patient Registry

Occupational lead exposure health risk assessment and heme biosynthesis: A study on batik artisans in yogyakarta, Indonesia

This study aims to assess dermal and inhalation lead exposure levels among batik industry workers and evaluate noncarcinogenic and carcinogenic health risks associated with lead exposure. We investigate potential relationships between lead exposure (dermal average daily dose and inhalation exposure concentration) and the workers' blood hemoglobin levels (Hb), as well as their urinary ALA (u-ALA) concentrations. Additionally, we explore any possible associations between Hb and u-ALA levels among the workers and identify various factors influencing lead exposure levels. A total of 30 workers were recruited for the study. Interviews and exposure sampling were conducted to measure dermal and inhaled lead exposure. Sample analysis methods include XRF for exposure samples, spectrophotometry for u-ALA, and HiCN colorimetric for Hb. Carcinogenic and noncarcinogenic risk assessments, correlation analysis, as well as ANOVA for factors analysis, were performed. The average dermal exposure dose and inhalation exposure concentration of lead were 6.53 ± 3.2 ng/kg/day and 0.021 ± 0.015 μg/m3, respectively. Hazard Index (HI) values for all workers were below 1 (average: 0.372 ± 0.155), indicating no expected noncarcinogenic health effects due to lead exposure. The average Excess Lifetime Cancer Risk (ELCR) was (5.18 ± 3.84) × 10−8, significantly below acceptable limits. Correlation analysis revealed a significant negative correlation between Hb and u-ALA (r = −0.519, p = 0.058 for male workers and r = −0.531, p = 0.034 for female workers), supporting their use as lead exposure biomarkers. The factors analysis demonstrated a significant impact of working conditions on inhalation exposure (p = 0.018), with outdoor workers experiencing lower lead inhalation. This research provides crucial insights into potential dangers faced by batik workers due to lead exposure, emphasizing the importance of targeted interventions. The strong correlation between Hb and u-ALA indicates their combined effectiveness in detecting lead exposure, even at low levels. The study underscores the significance of outdoor work as a protective measure against inhaling heavy metals, such as lead, present in the air. The assessment of health risks associated with lead exposure in the batik industry lays the groundwork for informed decision-making and interventions to protect workers' well-being, particularly in informal sectors workplaces where health risks are often overlooked.

Blood pressure and hypertension in relation to lead exposure updated according to present-day blood lead levels.

Lead is an environmental hazard that should be addressed worldwide. Over time, human lead exposure in the western world has fallen drastically to levels comparable to those in humans living in the pre-industrial era, who were mainly exposed to natural sources of lead. To re-evaluate the health risks possibly associated with present-day lead exposure, a three‑pronged approach was applied. First, we critically assessed the recently published population metrics describing the adverse health effects associated with lead exposure at the population level. Next, we summarized the key results of the Study for Promotion of Health in Recycling Lead (SPHERL; NCT02243904) and put these results in perspective with those of the published population metrics. Last but not least, we performed a brief literature review on the present-day lead exposure level in Poland. To our best knowledge, SPHERL is the first prospective study that accounted for interindividual variability between people in their vulnerability to the toxic effects of lead exposure by assessing the participants' health status before and after occupational lead exposure, with blood pressure and hypertension as one of the primary outcomes. The overall conclusion of this comprehensive review on blood pressure and hypertension is that mainstream ideas about the public and occupational health risks related to lead exposure urgently need to be updated, because a large part of the available literature became obsolete given present-day exposure levels, which sharply declined over the past 40 years.

Sources, blood concentrations, and approaches for reducing exposure to lead: A critical appraisal on lead poisoning

Lead, a non-essential metal, enters the body in various ways, making it a major public health issue. Painters and smelters report lead poisoning in children and staff. Mining and battery workers risk lead exposure. Traditional and cultural remedies may include dangerous quantities of lead, producing lead poisoning. These drugs must be properly understood and regulated to avoid toxicity. Lead poisoning symptoms vary by duration and severity. Lead first impairs cognition, development, and behaviour by damaging the neural system. Time degrades reproductive and haematological systems. Lead's quiet entry into the body makes it deadly. Acute lead nephropathy damages kidneys at 100mg/dL. Lead levels exceeding 150mg/dL may induce encephalopathy. Blood lead levels indicate lead poisoning severity. Lead levels over 10g/dL in children and 40g/dL in adults are hazardous. Lead toxicity affects various organs. Lead may induce hypertension and cardiovascular disease. It may also cause chronic kidney disease and renal failure. Lead exposure may impede fertility, cause miscarriages, and alter foetal development; hence the reproductive system is vulnerable. Symptoms and lead levels may be treated with different approaches. Lead chelation treatment is frequent. Other vitamins and medications may enhance organ function and treat lead poisoning. Lead poisoning prevention requires widespread awareness. Strict standards and education regarding lead-contaminated products and conventional remedies should reduce occupational lead exposure. Regular blood lead level monitoring, especially in youngsters and lead workers, may help detect and treat lead poisoning early. Lead poisoning has serious health consequences. Understanding lead exposure pathways, identifying symptoms, and preventing lead poisoning is essential to public health and organ system protection.

Role of MTHFR 677C>T and 1298A>C gene polymorphisms on renal toxicity caused by lead exposure in wastewater treatment plant workers

Environmental and occupational lead (Pb) exposures continue to pose major public health problems. Wastewater treatment plant (WWTP) workers proved are exposing to high Pb concentrations in sludge departments. The aim of the work was to investigate the role of MTHFR C677T and MTHFR A1298C gene polymorphisms on alteration of oxidative stress and homocysteine levels in WWTP workers exposed to high Pb concentrations, and study its relations with renal functions. The study included 90 WWTP workers from Abu-Rawash WWTP. Homocysteine, creatinine, urea, malondialdehyde (MDA), and total antioxidant capacity (TAC) were measured. Polymorphisms of MTHFR C677CT and MTHFR A1298C genes were studied using PCR/RFLP. Urine Pb concentrations were also measured. About 32.2% of the workers were with detectable Pb levels. Pb, homocysteine, and MDA levels were significantly higher among workers carrying TT polymorphism compared to other MTHFR C677T gene polymorphisms, while TAC was significantly lower among them compared to other polymorphisms. The same results were found among workers carrying CC compared to other MTHFR A1298C gene polymorphisms. WWTP workers carrying MTHFR 677TT and MTHFR 1298CC are more susceptible to elevation of homocysteine and the urinary Pb compared to the workers with the other polymorphisms. Furthermore, those workers were found to have increase in urea and creatinine. Therefore, MTHFR C677T and MTHFR A1298C gene polymorphisms could be used for prediction of the susceptibility to the risk of kidney impairments among WWTP workers in the sludge departments caused by their exposure to high Pb in their workplace.

Assessment of Diagnostic Accuracy and Clinical Utility of DNA Methylation (5-mC) in Detecting Severity of Occupational Lead Exposure.

This study investigated the diagnostic accuracy (DA) and clinical utility (CU) of DNA methylation (5 methylcytosine) in occupational Pb-exposure from Pb based industry. Blood Lead levels (BLLs) were measured using the ICP-OES method. The total DNA methylation (5-mC) was quantified using ELISA method. Based on their BLLs, the Pb-exposed workers were categorised into three groups: low (< 10µg/dL), moderate (10-30µg/dL), and high exposure (> 30µg/dL). DNA methylation (5-mC) was significantly lower in moderate and high Pb-exposure groups when compared to the low Pb-exposure group. Workers exposed to high levels of Pb-exposure, the DA variables of 5-mC showed that the sensitivity was 74.7% [95% CI 65.4-84.0], specificity was 69.6% [95% CI 50.8-88.4], positive predictive value (PPV) was 89.9% [95% CI 82.7-97.0], Postive likelihood ratio (LR+) was 2.454 [95% CI 1.3-4.6], and diagnostic odds ratio (DOR) is 6.3 [95% CI 6.5-7.7]. In moderate Pb-exposure, the DA variables of 5-mC revealed that the sensitivity is 64.9% [95% CI 55.2-74.5], the specificity is 69.6% [95% CI 50.8-88.4], the PPV is 89.7% [95% CI 82.5-97.0], the LR+ is 2.132 [95% CI 1.13-4.03], and the DOR is 4.2 [95% CI 3.6-5.7]. The high Pb-exposure group had higher DA metrics when compared to moderate Pb exposure. The clinical utility (CU+) of 5-mC was found to have good utility of 0.671 [95% CI 0.566-0.776] in the high Pb exposure group and fair utility of 0.582 [95% CI 0.470-0.694] in moderate Pb exposure group. In conclusion, DNA methylation (5mC) could be used as a predictive biomarker for high Pb-exposure.

Does Occupational Lead Exposure Affect the Relationship Between Neurobehavioral Characteristics and Productivity?

Background &amp; Aims: Lead (Pb) may cause cognitive impairments in both recent acute and chronic exposures. In this study, the effect of Pb exposure on the relationship between neurobehavioral characteristics and productivity was evaluated among battery manufacturing workers. Materials and Methods: In general, 179 production workers and 179 office workers participated in this cross-sectional study. Venous blood sampling was used to measure the level of Pb in the blood. Psychomotor performance and intellectual functioning were measured using the digit symbol substitution test and the Wechsler adult intelligence scale-revised, respectively. Finally, productivity was assessed using a health and work performance questionnaire. Results: Exposed workers had a significantly higher level of Pb, while a lower level of intellectual functioning and psychomotor performance than non-exposed workers. The results of linear regression indicated that the increase in the blood level of Pb was accompanied by a significant decrease in the positive effects of intellectual functioning on productivity. However, exposure to Pb had no effect on the relationship between psychomotor performance and productivity. Conclusion: Occupational exposure to Pb affected the relationship between psycho-diagnostic performance and productivity and could induce neurobehavioral dysfunction in the exposed workers. For the early detection of cognitive impairment, the neurobehavioral assessment is recommended to be implemented in work assessments.

Retrospective Evaluation of Liver and Kidney Functions in Patients with Chronic Occupational Lead Intoxication Treated with EDTA Chelation Therapy

Objective: This study aimed to investigate hepatic and renal functions in patients who received calcium disodium edetate (CaNa2EDTA) chelation treatment for chronic occupational lead intoxication. Material and Methods: This single-center retrospective descriptive research was conducted in a secondary-level health facility. The study included patients treated with CaNa2EDTA chelation for chronic occupational lead intoxication between September 15, 2020, and May 31, 2021. Demographic and occupational characteristics, as well as and laboratory parameters obtained before and after the chelation therapy were evaluated. Results: All 75 patients were male, and 73.3% had an occupation in metal scrap recycling. Renal parameters were within normal range before and after the chelation. However, mild elevations were observed in liver parameters. After the adjustment for demographic and occupational variables, the odds of having an elevated liver parameter and an elevated alanine transaminase (ALT) result after the chelation therapy were 9.3 (95%CI 2.6–33.2, p&lt;0.001) and 11.4 (95%CI 2.4–53.2, p&lt;0.001) for patients with pre-chelation elevated any liver parameter and pre-chelation elevated ALT result, respectively. Conclusion: The current study documented mild elevations of the liver parameters in patients with chronic occupational lead poisoning after CaNa2EDTA chelation therapy, particularly those with elevated basal liver parameters, although their renal parameters stayed within reference ranges. The results serve as an example of the safe application of CaNa2EDTA chelation for chronic occupational lead poisoning, by monitoring kidney and liver parameters in a secondary-level health facility. Future prospective studies with structured treatment protocols may investigate the risk and determinants of hepatic and renal adverse effects.

S-23-5: TWO-YEAR RESPONSES OF OFFICE AND AMBULATORY BLOOD PRESSURE TO FIRST OCCUPATIONAL LEAD EXPOSURE

Lead exposure causing hypertension is the mechanism commonly assumed to set off premature death and cardiovascular complications. However, at current exposure levels in the developed world, the link between hypertension and lead remains unproven. In the Study for Promotion of Health in Recycling Lead (NCT02243904), we recorded the 2 year responses of office blood pressure (OBP, average of five consecutive readings) and 24 h ambulatory blood pressure (ABP) to first occupational lead exposure in workers newly employed at lead recycling plants. Blood lead (BL) was measured by inductively coupled plasma mass spectrometry (detection limit 0.5 μg/dL). Hypertension was defined according to the 2017 ACC/AHA guideline. Statistical methods included multivariable-adjusted mixed models with participants modelled as a random effect and interval-censored Cox regression. OBP was measured in 267 participants (11.6% women, mean age at enrollment, 28.6 years) and ABP in 137 at two follow-up visits. Geometric means were 4.09 μg/dL for baseline BL and 3.30 for the last-follow-up-to-baseline BL ratio. Fully adjusted changes in systolic/diastolic blood pressure associated with a doubling of the BL ratio were 0.36/0.28 mm Hg (95% confidence interval, 0.55 to 1.27/ 0.48 to 1.04 mm Hg) for OBP and 0.18/0.11 mm Hg (2.09 to 1.74/ 1.05 to 1.27 mm Hg) for 24 h ABP. The adjusted hazard ratios of moving up across hypertension categories for a doubling in blood lead were 1.13 (0.93–1.38) and 0.84 (0.57–1.22) for OBP and ABP, respectively. In conclusion, the 2 year blood pressure responses and incident hypertension were not associated with the BL increase on first occupational exposure.