The objectives of this study were to investigate the impact of heavy metals in two
freshwater decapods and to evaluate the toxicity and human health risks through
the consumption of these freshwater decapods. Nine (9) heavy metals were
investigated in accordance with standard procedures and analyzed monthly from
March 2015-August 2016 in the studied decapods. The results of the heavy metal
concentrations in the prawn and crab varied in this rank; Fe > Zn > Mn > Cu > Pb >
Cd > Cr > Ni = V for prawn and Zn > Fe > Mn > Cu > Pb > Cd > Cr > Ni = V for shrimp.
The results of the human health risk assessments revealed high values of Iron (Fe)
and Zinc (Zn) for the target hazard quotient (THQ) and estimated daily intake (EDI)
as well as high values of Iron (Fe), Zinc (Zn), and Manganese (Mn) for the health
risk impact (HRI). All most all the values obtained were above allowable limits in
prawn and crab respectively. Strict environmental laws should be reinforced and
compliance should be adhered to in order to protect humans from consuming
freshwater decapods sourced from various points.