Elsevier

Environmental Research

Volume 165, August 2018, Pages 420-424
Environmental Research

Lead intoxicated children in Kabwe, Zambia

https://doi.org/10.1016/j.envres.2017.10.024Get rights and content

Highlights

  • Kabwe's soil is highly contaminated with lead due to former lead mining.

  • Children from highly contaminated townships showed high blood lead levels.

  • They need to be treated and the exposure must be considerably reduced.

Abstract

Kabwe is a lead contaminated mining town in Zambia. Kabwe has extensive lead contaminated soil and children in Kabwe ingest and inhale high quantities of this toxic dust. The aim of this paper is to analyze the health impact of this exposure for children. Health data from three existing studies were re-analyzed. Over 95% of children living in the most affected townships had high blood lead levels (BLLs) > 10 µg/dL. Approximately 50% of those children had BLLs ≥ 45 µg/dL. The existing data clearly establishes the presence of a severe environmental health crisis in Kabwe which warrants immediate attention.

Introduction

Kabwe is the fourth biggest town and capital of the central province of Zambia. The town has a long history of mining, which operated for more than 90 years and produced large quantities of lead (Pb) and zinc (Zn) until closure in 1994.

Lead is a toxic substance and chronic exposure causes serious adverse health effects. The pathways of exposure are mainly ingestion of Pb contaminated soil and dust, but inhalation as a route of entry can also be significant. Pb can cause acute and chronic intoxication. High exposure can cause severe colic-like abdominal pains, neurological symptoms, seizures, encephalopathy and finally death (World Health Organization, 2010).

Infants are at higher risk due to specific risk behaviors such as playing on bare soil, relevant hand to mouth activity and thus their oral uptake is greater compared with adults (World Health Organization, 2010). While high blood Pb levels (BLLs) have been associated with extensive adverse effects, evidence of low BLLs causing serious negative health effects is extensive and conclusive. The negative effect of Pb exposure during pregnancy to the fetus and during early childhood on the regular development of the brain has enormous adverse implications (Advisory Committee on Childhood Lead Poisoning Prevention, 2016, Needleman et al., 1990).

The CDC Reference Level for Pb is 5 µg Pb/dL blood (https://www.cdc.gov/nceh/lead/acclpp/blood_lead_levels.htm). Between 5 and 44 µg Pb/dL, actions to lower the body burden are recommended In the former “Kabwe lead poisoning management protocol” a Pb level of 20 µg Pb/dL was considered as minimum level for individual follow up (Project Technical Committee - Zambia Consolidated Copper Mines Investments Holdings, 2006). The medical intervention level for children is 45 µg Pb/dL. Children with confirmed Pb encephalopathy need to be hospitalized and treated individually (Advisory Committee on Childhood Lead Poisoning Prevention, 2016, Thurtle et al., 2014). Data from a large treatment survey in Nigeria indicates that oral chelation treatment with Chemet® (succimer, DMSA) is both safe and effective (Thurtle et al., 2014). However, chelation therapy without environmental intervention may prove futile since re-exposure will likely occur.

Section snippets

Environmental assessments

Lead contaminated soils in Kabwe pose a serious environmental hazard. In 2003–2006, the “Copperbelt Environment Project” analyzed over 1000 soil samples for Pb in various townships. The results showed, that the soil “over a substantial area is highly contaminated with the metal”. “Median Pb concentrations of soil in townships in the vicinity of the mine inducing Kasanda (3008 mg/kg), Makandanyama (1613 mg/kg), Chowa (1233 mg/kg), Mutwe Wansofu (1148 mg/kg), Makululu (870 mg/kg) and Luangwa (507 

Health assessments

Presently, there are three information sources on childhood BLLs in Kabwe; (1) data from the Copperbelt Environment Project; (2) data from projects of Pure Earth and (3) data from a University of Zambia with collaborators from Hokkaido University, Japan. A summary of BLL data is provided below.

Discussion

The existing data clearly establishes the severity of Pb exposure in Kabwe. Environmental data also support the observation that in certain housing areas of Kabwe, the recommended tolerable soil Pb level of 400 mg/kg is clearly exceeded (see Fig. 1 and Fig. 2). The soil levels measured by Pure Earth 2014 are in general higher compared to those reported by KSDS in 2006. We suspect this results from enhanced granularity now available with a portable XRF (rather than an actual increase in

Acknowledgement

Funding by Pure Earth is gratefully acknowledged (JC). Funding from the European Union's Seventh Programme for research, technological development and demonstration under grant agreement No 603946 (Health and Environment-wide Associations based on Large population Surveys, HEALS) is acknowledged (SB).

References (14)

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