Abstract:
Metal processing industries all over the world have been cited as obvious point sources of heavy metals to the environment. Although, this has been done, we have little information on the role of Jua Kali enterprises as sources of these metals to the environment. Such metals may end up in the food chain to affect man and animals at last. Soil, grass, leaves of kales leaves (Brassica Oleraceae) and chicken tissues were sampled fiom selected Jua Kali sites of Nairobi, Naivasha and Nakuru. All samples were acid- digested and the levels of lead, cadmium and zinc determined using ChemTe<:h Analytical CTA-2000 Atomic Absorption Spectrophotometer in parts per million. The results indicated that, Jua Kali enterprises contribute quite a substantial amount of cadmium, lead and zinc into the environment ranging fi'om 400- l,290pg/g for total soil metal levels at all sites. The available zinc, cadmium and lead in soils for plants in all Jua Kali sites ranged between 480—54Oug/g. Grass and kale leaves had levels between 4- 420ug/g with grass samples having highest levels than kale leaves. Kidney and liver tissues of chicken kept in the residential areas near the sites and moving fieely into the sites in search of food, had levels ranging between 2—8ug/g. These values are above the reported values for similar samples collected from uncontaminated areas. Thus, Jua Kali entetpriscs are significant point sources of cadmium, lead and zinc metals whose environmental impacts have been overlooked.
