摘要：This study was carried out to assess the concentration levels of heavy metals in vegetables grown on urban waste dumpsites. The research was carried out on three waste dumpsites in Kumasi where vegetables cultivation (cabbage, lettuce and spring onions) are practised. Experimental plots of cabbage, lettuce and spring onions were set up at these sites and harvested at complete maturity stage. Crops and soil samples were collected and analysed for the presence of four heavy metals: cadmium, lead, copper and zinc. Cadmium levels recorded were in the range of 0.68-1.78 mg kg-1 as against WHO/FAO recommended level of 0.20 mg kg-1; lead had values in the range of 2.42-13.50 mg kg-1 as against the WHO/FAO recommended guideline value of 0.30 mg kg-1; copper levels were in the range of 16.17-90.33 mg kg-1 as against the WHO/FAO recommended guideline value of 73.3 mg kg-1 and zinc had values between 26.77-106.83 mg kg-1 compared to the WHO/FAO recommended guideline value of 99.40 mg kg-1. The levels of the two most toxic heavy metals, cadmium and lead, were far higher in the vegetables than the WHO/FAO recommended values and the transfer factors of these two metals were also the highest suggesting that consumption of vegetables grown on such sites could be dangerous to human health.
