Emerging aspects of assessing lead poisoning in childhood

One Health: Children, Waterfowl, and Lead Exposure in Northwestern Nigeria

The One Health concept focuses on the interrelationship between the health of humans, animals, and the environment. There is a delicate balance among these relationships, and when an imbalance exists, the effects can be catastrophic. Such an imbalance occurred in 2010, when elevated lead exposure in rural communities in northwestern Nigeria resulted in the deaths of an estimated 400 children younger than 5 years in a 12-month period. Before the children became ill, waterfowl began to die in great numbers, a connection that would not be realized until much later. This review covers toxicodynamics and the neurotoxic effects of lead in the developing central nervous system, the role that animals can play in recognizing lead exposure and contamination, and environmental sources of lead exposure. The experiences in Nigeria may be especially pertinent to the emerging problems associated with lead exposure and poisoning in the United States.

Blood Lead Levels and Risk Factors among Preschool Children in a Lead Polluted Area in Taizhou, China

Objective. To determine the blood lead levels and identify related risk factors among preschool children in a lead polluted area (Taizhou, China) and provide theoretical support for prevention of lead pollution. Methods. A stratified-clustered-random sampling method was used to determine the survey sample. Blood lead levels were determined by the tungsten atomizer absorption spectrophotometer. Results. A total of 2,018 subjects (average age of 59 months; 1,087 boys and 931 girls) were included. The arithmetic mean, geometric mean, and median blood lead levels of the preschool children were 56.4 μg/L, 48.9 μg/L, and 46 μg/L. A total of 8.8% children had blood lead levels >100 μg/L and 43.9% had blood lead levels >50 μg/L. Mother's education level, father's occupation, decorative tableware, exposure to makeup, and the residential floor were all risk factors for elevated blood lead levels (odds ratios of 1.42, 1.21, 1.11, 1.19, and 1.27, resp.), while hand washing before eating food was a protective factor (odds ratio of 0.88). Conclusions. The blood lead levels of preschool children in Taizhou were higher than in other areas in China and in developed countries. Therefore, policies ensuring lead-based industries are not placed in close proximity to residential areas are required.

A protocol for a systematic review of the effectiveness of interventions to reduce exposure to lead through consumer products and drinking water

BACKGROUND

The toxic heavy metal lead continues to be a leading environmental risk factor, with the number of attributable deaths having doubled between 1990 and 2010. Although major sources of lead exposure, in particular lead in petrol, have been significantly reduced in recent decades, lead is still used in a wide range of processes and objects, with developing countries disproportionally affected. The objective of this systematic review is to assess the effectiveness of regulatory, environmental and educational interventions for reducing blood lead levels and associated health outcomes in children, pregnant women and the general population.

METHODS/DESIGN

The databases MEDLINE, Embase and the Global Health Library (GHL) will be searched using a sensitive search strategy. Studies in English, German, French, Spanish, Italian or Afrikaans will be screened according to predefined inclusion and exclusion criteria. We will consider randomized and non-randomized studies accepted by the Cochrane Effective Practice and Organization of Care (EPOC) Group, as well as additional non-randomized studies. Screening of titles and abstracts will be performed by one author. Full texts of potentially relevant studies will be independently assessed for eligibility by two authors. A single author will extract data, with a second reviewer checking the extraction form. Risk of bias will be assessed by two researchers using the Graphical Appraisal Tool for Epidemiological studies, as modified by the Centre for Public Health at the UK National Institute for Health and Care Excellence. Any inconsistencies in the assessment of eligibility, data extraction or quality appraisal will be resolved through discussion. Where two or more studies report the primary outcome blood lead levels within the same population group, intervention category and source of lead exposure, data will be pooled using random effects meta-analysis. In parallel, harvest plots as a graphical method of evidence synthesis will be used to present findings for blood lead levels and secondary outcomes.

DISCUSSION

This systematic review will fill an important evidence gap with respect to the effectiveness of interventions to reduce lead in consumer products and drinking water in the context of new WHO guidelines for the prevention and management of lead poisoning. It will also contribute to setting a future research agenda.

Exposure of lead to mothers and their new born infants, residents of industrial and domestic areas of Pakistan

Prenatal and early-life exposure to lead (Pb) is hypothesized to have adverse effects on childhood health. The aim of this study was to evaluate the prenatal exposure to Pb and its adverse effects on mothers and their infants who are residents of industrial (exposed) and domestic areas (referents) in Karachi, Pakistan. The biological samples (scalp hair and blood) of mother-infants pairs were analyzed for Pb levels by atomic absorption spectrometry after microwave-assisted acid digestion method. The Pb levels in scalp hair and blood samples of exposed mothers were found in the range of 7.52-8.70 μg/g and 115-270 μg/L, respectively, which were significantly higher than those values obtained for referent mothers (p < 0.001). The Pb levels in the blood (umbilical cord) and hair of neonates of exposed mother that were found in the range of 83-178 μg/L and 4.95-7.23 μg/g, respectively, were significantly higher than the obtained values of referent neonates (p > 0.001). The correlation between maternal and cord blood of both groups was found in the range of 0.708-0.724 (p < 0.01). It was observed that there were higher Pb burdens in exposed mothers and their infants as compared to referent mothers-neonates.