Background: Communities around Kabwe/Zambia are exposed to lead due to deposits from an old lead (Pb) and zinc (Zn) mining site. Children are particularly more vulnerable than adults, presenting with greatest risk of health complications because of their increased oral uptake due to their hand to mouth activities. Spatial analysis of childhood lead exposure is useful in identifying specific areas with highest risk of pollution. The objective of the current study was to use a geospatial approach investigate spatial clustering and hotspots of blood lead levels in children within Kabwe.
Methods We analysed data on blood lead levels (BLL) for 363 children below the age of 15 from Kabwe town. We used spatial autocorrelation methods involving the global Morans I and local Getis-Ord Gi statistic in ArcMap 10.5.1, to test for spatial dependency among the blood lead levels in children.
Results BLL in children from Kabwe are spatially autocorrelated with a Morans Index of 0.62 (p<0.001). We found distinct hot spots in communities close to the old lead and zinc-mining site, lying on its western side. We observed lower levels of BLL in areas distant to the mine and located at its eastern side. This pattern suggests a possible association between BLL and distance from the abandoned lead and zinc mine, and prevailing winds.
Conclusion Using geocoded data, we found clustering of childhood blood lead and identified distinct hot spot areas with particular high lead levels for Kabwe town. The geospatial approach used is especially valuable in resource- constrained settings like Zambia, where the precise identification of the locations of risk areas allows to initiate targeted remedial and treatment programs.
Keywords: Spatial cluster, Geospatial, blood lead, hot spots, Morans I
Geospatial approach to investigate spatial clustering and hotspots of blood lead levels in children within Kabwe, Zambia