Blood lead levels in children attending a tertiary teaching hospital in Enugu, south-eastern Nigeria

Association between lead source exposure and blood lead levels in some lead manufacturing countries: A systematic review and meta-analysis

Lead is one of the 10 most toxic chemicals of greatest concern for its effects on public health. Predominantly, in undeveloped countries, high blood lead levels (BLLs) persist in the population. To develop intervention strategies that may reduce lead exposure in populations, it is a priority to know the sources of lead pollution. The objective of this critical review and meta-analysis is to assess whether there is an association between different sources of lead exposure and the mean difference in blood lead levels in people exposed. To identify the major lead source exposure, a statistical analysis was performed on selection studies. This investigation reveals the limited information available on the sources of lead in Mexico and other lead producer countries, such as Croatia, Ecuador, Brazil, South Korea, India, Nigeria, Turkey, and China. Meta-analysis could be performed only in battery, smelting mining, and glazed ceramic workers. Battery manufacturing workers have the highest mean difference level of lead in their blood worldwide. Mexico has the second highest mean difference BLL in battery workers in the world. An interesting difference between the mean difference in BLL in mining workers from uncontrolled industry (-39.38) and controlled industry (-5.68) was found. This difference highlighted the success of applying strict control of lead sources and community education to reduce BLL and its potential harmful effects on human health and the environment. Children living near mining sites have the highest mean difference BLL (-11.1). This analysis may aid in assessing the source of lead exposure associated with a range of BLLs in people. Furthermore, this review highlights several social and cultural patterns associated with lead exposure and lead levels in control populations. These results could help to develop international lead regulations and appropriate public health guidelines to protect people around the world.

Biomonitoring of Lead Exposure in Children from Two Fishing Communities at Northern Colombia

Lead (Pb) exposure is a growing concern in developing countries, especially in vulnerable children. The objective of this study was to evaluate blood lead levels (BLL) in children from two fishing populations at Northern Colombia, Loma de Arena and Tierrabomba, as well as their association with morphometric parameters, markers of hematological status, liver function, and mRNA expression of genes related to Pb toxicity. A total of 198 blood samples were collected from participants aged 5-16 years old. The mean (± standard error) BLL for the studied sample was 3.6 ± 0.3 μg/dL, and the 97.5th percentile was 21.0 μg/dL. The participants of Loma de Arena and Tierrabomba presented BLL of 3.9 ± 0.5 and 2.9 ± 0.3 μg/dL, respectively. Children born preterm had greater BLL than those born at full term. Boys had greater BLL than girls, which also occurred for participants between 12 and 16 years old, compared with those aged 5-11 years old. The BLL were negatively correlated with body mass index in children from Loma de Arena, but an opposite behavior was observed for Tierrabomba. In Loma de Arena, the mRNA expression of interferon gamma, a pro-inflammatory cytokine, increased with the BLL, but that of δ-aminolevulinic acid dehydrogenase, a sensor for Pb poisoning, decreased. In Tierrabomba, gene expression did not change with BLL. These results show that in fishing communities, lead exposure promotes different health impacts depending on age, sex, and other site-specific factors. In any case, appropriate educational and intervention programs should be carried out to minimize Pb exposure in children.

Blood Pressure and Lipid Profile in Automechanics in Relation to Lead Exposure

Context

Elevated blood pressure and alterations in lipid and lipoproteins play a major role in the development and progression of cardiovascular diseases.

Aim

This study is aimed at determining the blood pressure and lipid profile in automechanics.

Settings and Design

A total of 120 male subjects between 18 and 55 years of age comprised 60 automechanics and 60 age-matched occupationally unexposed control subjects in Emene, Enugu State, Nigeria.

Subjects and Methods

Four milliliters of fasting blood samples was collected from all subjects, 2 mL of blood was dispensed into K₂-EDTA vacutainer tube for blood lead analysis, while the other 2 mL was dispensed into plain vacutainer tube, allowed to retract, centrifuged, and the serum used for serum lipid profile analysis. Blood pressure was measured using aneroid sphygmomanometer.

Statistical Analysis

Statistical Package for Social Sciences (SPSS) version 21.0 was used for data analysis.

Results

Automechanics had significantly higher values of systolic and diastolic blood pressures compared with the controls. Serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and triglyceride (TG) were also significantly higher in the automechanics compared with the controls (P < 0.05); serum high-density lipoprotein cholesterol (HDL-C) level, however, did not differ significantly between the two groups (P > 0.05). Blood lead level showed a significant positive correlation (P < 0.05) with systolic and diastolic blood pressures, serum TC, LDL-C, VLDL-C, and TG, with no significant correlation with serum HDL-C (P > 0.05) in the automechanics and no correlation in the controls.

Conclusion

The result of this study indicates that blood pressure is elevated and lipid profile altered in automechanics which suggests that these groups of workers are prone to increased risk of developing hypertension and cardiovascular disorders due to occupational exposure to lead.

Blood Lead Levels among Children in Yaoundé Cameroon

Blood lead levels (BLLs) are a useful indication of a population exposure to lead from environmental sources. No previous published study had reported BLLs in Cameroon. Our objective is to characterize exposure levels in children to inform policymakers of potential lead exposure sources. We tested the BLLs of 147 children aged 12 months to 6 years residing in Yaoundé, Cameroon, and conducted an extensive questionnaire with their parents or guardians to characterize potential exposure sources. The geometric mean BLL among this population was 8.0 μg/dl and arithmetic mean level was 8.7 μg/dl. These levels are more than sixfold higher than the geometric mean BLL reported in the U.S. and more than fivefold higher than those reported in France. In addition, 88% of the children tested had lead levels greater than 5 μg/dl. One limitation of the study is that the selection of the children sampled was not a random survey. The analysis of the responses to the questionnaire failed to uncover any specific exposure patterns. A statistically significant association was noted between the age of the child’s home and the duration of exclusive breastfeeding with BLLs. The study points to a need for greater efforts to control sources of lead exposure in Cameroon.