Abstract:

The concentrations of Cadmium (Cd), Copper (Cu). Lead (Pb) and Zinc (Zn) in Heterobranchus
longfilis (Mean total length- 40.52 cm: mean \veight~563.25 g) cultured in earthen ponds in Warn, Nigeria,
were determined by Atomic Absorption Spectrometric technique in order to provide baseline data and to
ascertain the suitability of such fish for consumption. The mean concentrations of metals in //. longifilis, ranged
from 0.13 nig/kg for Cd in January to 72.51 mg/kg ibr Cu in June with significant differences (p<0.05) observed
in the mean concentrations of Cu, Pb and Zn in fish between months. The mean concentrations of metals in //.
longifilis, ranged fiom 0J2 nig/kg fbr Cd al Jeddo to 69.27 nig/kg for Cu at Ubeji with significant difierences
(p<0.05) observed in the mean concemration of Zn in fish beiween stations. The bioaccumulation quotient (BQ)
values ranged from 0.50 for Cd al Jeddo to 37.24 for Cu at Oboroke while the hazard quotient (HQ) ranged from
0.39 for Zn to 3.43 for Pb. The maximum acceptable risk (MAR) values ranged from 0.02 for Pb at Ekpan to
6.29 for Zn at Ubeji while the estimated average daily intake (EADI) of heavy metals ranged from 0.09
mg/person/day for Cd to 36.13 mg/person/day for Cu. Il was concluded that Cd, Cu and Pb were the metals that
presented a potential risk to the consuming public and that the heavy metal content in earthen ponds should be
routinely monitored in order to keep metal levels within safe limits.