Abstract

Heavy metals do not decay in the environment and can results to entering the food chain. The study was
conducted to evaluate the absorption of heavy metals from poultry feeds. Nine metals (Zn, Cd, Fe, Cu, Ni, As,
Pb, Mn, Cr) were analysed in this work, using atomic absorption spectrophotometry in different poultry feeds
used in Kebbi state (3 commercial and three locally made). The samples were digested using concentrated
HNO3 and HCLO4 at about 370oC in a digestion block. The mean concentration of the metals in ppm analysed
in the feed samples ranges between 0.07-1.16 Zn, 0.01-0.03 Cd, 0.42-11.62 Fe, 0.04-0.61 Cu, 0.00-0.03 Ni,
0.01-0.03 As, 0.03-0.07 Pb, 0.05-0.50 Mn and 0.00-0,01 Cr. From the results, the mean concentration of Cd,
As and Pb in all the poultry feeds were lower than the permissible limits, meaning they are at a non-toxic level.
On the other hand, Zn, Fe, Cu, Ni and Mn in all the samples were found to be below the required level as
micronutrients for poultry animals. Therefore, there should be an increased efforts to increase these nutrients
as supplements in the poultry feeds. The daily intake of metals by children via the feeds were found to be higher
than that of the adults. Moreover, the hazard quotients of all the metal contaminants for children were shown
to be above that of the adults but all were found to be less than 1, while the hazard index of all the metals in
both populations were discovered to be less than one. However, samples E and F show hazard index of 0.70
and 0.60 values that are close to 1 for children. This implies that long term ingestion exposure via food chain
could lead to accumulation of As, Cd and Pb which may result to health risk effects on children. The cancer
and non-cancer risk effects for both populations were within the safe and acceptable limits.

Key words: Health risk, heavy metals, poultry feeds, contamination, food chain, Kebbi state.