Lead exposure and early child neurodevelopment among children 12–24 months in Kinshasa, the Democratic Republic of Congo

Espérance Kashala-Abotnes,Makila-Mabe Guy Bumoko,Désiré Tshala-Katumbay,Pépé Penghele Mumbere,Daniel Luwa E-Andjafono Okitundu,Tharcisse Kalula Kayembe,Jeannette Mukanya Mishika,Ally Omba Ndjukendi,Davin Beya Mpaka,Théodore Kayembe Kazadi

doi:10.1007/s00787-016-0860-3

Abstract

Childhood lead exposure remains a problem in developing countries, and little is known about its effects on early child neurodevelopment and temperament in the Democratic Republic of Congo (DRC). We, therefore, conducted this study to determine the association between lead exposure and the neurodevelopment and behaviour of children aged 12–24 months in Kinshasa, DRC. A cross-sectional study was conducted between February and June 2012, and parents of 104 children were invited to participate. Blood lead levels (BLLs) of each child were tested using the flame atomic spectrophotometry method. All children were subject to a clinical examination and assessed with two selected early child neurodevelopmental tools, the Gensini–Gavito and the baby characteristics questionnaire, to measure their neurodevelopment and temperament. Detectable BLLs ranged from 1 to 30 μg/dl with a geometric mean of 6.9 (SD 4.8) μg/dl. BLLs at 5–9 and ≥10 μg/dl were significantly associated with the child temperament (p <0.05). Perinatal and maternal factors did not seem to affect early child neurodevelopment and temperament. Children exposed to lead were reported with more temperament difficulties at even blood lead levels <10 μg/dl, suggesting the need for preventive and intervention measures to reduce lead exposure among children in Kinshasa, DRC.

Highlights

Lead exposure remains an important public health challenge in the world, in Africa due to, among other factors, poverty, low level of awareness and poor capacity to enforce legislation [1]
Of the 104 children selected to participate in the study, six were excluded due to signs of malnutrition identified during the clinical examination
Independent effects of blood lead levels on child neurodevelopment and temperament We looked at the Blood lead levels (BLLs) as a continuous variable, and found a significant correlation with the child temperament (Kendall’s tau coef. 0.17; p value 0.02)

Summary

Introduction

Lead exposure remains an important public health challenge in the world, in Africa due to, among other factors, poverty, low level of awareness and poor capacity to enforce legislation [1]. An increasing number of studies suggested that childhood lead exposure increases the risk for neurodevelopmental delays, behavioural problems and cognitive impairments even at blood lead levels below 10 μg/dl [3,4,5]. These impairments may persist into adolescence and adulthood, altering the optimal development of exposed children [6, 7]. The centers for disease control (CDC) eliminated the terminology “level of concern” and advised that children with blood lead levels requiring public health action should be identified using the reference value of 5 μg/dl. This value, generated by the national health and nutrition examination survey (NHANES), is based on the 97.5th percentile of blood lead level distribution among children aged 1–5 years old living in the United States of America (http://www.cdc.gov/mmwr/preview/mmwrhtml/ mm6120a6.htm)

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