Determination of heavy metals in dust from selected nursery and kindergarten classrooms within the Kumasi metropolis of Ghana

Abstract

The exposure potential of children in nursery and kindergarten schools to metals in dust in the Kumasi Metropolis was studied. Dust samples from 20 selected schools were analyzed for heavy metal levels using atomic absorption spectropho-tometry. The results showed that concentrations were in the range of below detection −9.710 μg/g for cobalt, below detection to 33.291 μg/g for chromium, below detection to 41.909 μg/g for lead, below detection to 1.383 μg/g for mercury, while cadmium levels were below detection for all samples. The mean levels of metals therefore decreased in the order: Cr > Pb > Co > Hg and Cd. Geographical variation correlated with heavy metal load. Health risk assessment using hazard quotient (HQ) and hazard index (HI) calculations indicated that ingestion contributed more to exposure than dermal contact. However, the values obtained by HQ and HI do not pose any immediate health risk but the cumulative effect is a matter of concern.