TOXIC AND ESSENTIAL METAL CONCENTRATIONS IN ROASTED PLANTAIN AND FISH COMMONLY CONSUMED BY PORT HARCOURT INHABITANTS, RIVERS STATE, NIGERIA

Abstract

Of recent, the consumption of roasted Plantain and fish popularly known as
Bole during lunch hours in Port Harcourt has been on the increase. Considering the
open nature by which this meal is prepared along roadside and the industrial
concentrations of the Port Harcourt metropolis, most inhabitants of the city believed
that these food items may have been polluted by metals. Hence, this study was
necessitated to actually ascertain the levels of some toxic and essential metals in
roasted plantain and fish in the city. Food samples were collected from eight
locations based on high population of the area, high vehicular movements and
presence of industries. The collected food samples were prepared, digested and
subjected to heavy metals analyses using the atomic absorption spectroscopy. The
results of the detectable concentrations (mg/kg) of the metals in the roasted plantain
were: Cd (0.062±0.1289) mg/kg, Pb (0.135±0.1207) mg/kg, Zn (21.33±13.203)
mg/kg, Fe (58.19±14.73) mg/kg, Cr (0.054±0.3002) mg/kg, Mn (0.026±0.0273)
mg/kg, Ag (0.036±0.0197) mg/kg and As (0.038±0.0243) mg/kg. In the roasted fish
the mean concentrations with standard deviation were: Cd (0.007±0327) mg/kg, Pb
(0.07±0.066) mg/kg, Zn (29.6±27.34)mg/kg, Fe (44.103±19.838)mg/kg, Cr
(0.64±0.289)mg/kg, Mn(0.03±0.0192) mg/kg, Ag(0.0215±0.0174) mg/kg and
As(0.0145±0.0141)mg/kg. These results showed that the mean concentration of all
the essential metals in roasted plantain and fish were within the recommended limit
set by WHO/FAO. For the heavy metals, the mean concentrations were within the
recommended limits in the plantain and fish except in few locations where the
concentrations of Pb, Cd, Ag and As were slightly elevated. Based on the findings,
roasted plantain and fish may be considered fit for consumption. The slight increase
in concentration at some locations however calls for caution considering the nonbiodegradable
nature and accumulative properties of heavy metals.