Heavy metal burdens of public primary school children related to playground soils and classroom dusts in Ibadan North-West local government area, Nigeria

- Soil-human body heavy metal inter-relationship is rarely studied in developing economies like Nigeria.
- This relationship was studied in children in urban and semi-rural settings in Nigeria.
- A weak but significant soil-blood Pb relationship was found.
- Soil Pb and other bioaccessible sources of Pb might be predictors of blood Pb in children (in Nigeria).

Information about heavy metal burden of children in Nigeria related to playground soils and classroom dusts is lacking. Playground soil, classroom dust, blood and spot urine samples (n = 253) were collected from 6 urban and 2 semi-rural public schools in Ibadan North-West, Nigeria. Samples were analysed for Pb, Cu, Zn, Fe and Mn. Mean blood Pb levels in urban area (male, 41.66 ± 8.78 μg/dl vs. female, 40.64 ± 5.46 μg/dl) were twice as high as those in semi-rural area (male, 19.71 ± 3.73 μg/dl vs. female, 20.65 ± 2.26 μg/dl). Concentrations of Pb, Cu, Zn, and Fe in soil and dust samples in the urban schools were between 2- to 4-fold greater than that of semi-rural schools. No correlation was observed between blood and dust metals. A positive correlation (r = 0.168, p = 0.008) was observed between blood Pb and playground soil Pb. Pb burden in the children might be from their schools' playgrounds and other yet unidentified sources.