Abstract:
The safe disposal of Water Treatment Sludge has become one of the main environmental
concerns throughout the world due to the enormous quantity of sludge generated. Typically, the
sludge discharge to river bodies affect fish species. This study investigates the effect of water
treatment sludge on bioaccumulation of heavy metals in water, fish (Oreochromisniloticus, and
Clariasgariepinus) from river ChanchagaMinna Niger State, Nigeria and the human health risk
associated with their consumption. Fishes and water samples were collected from river
contaminated with sludge (River Chanchaga) and other samples from a private farm where there
were no sludge served as control (Makolo farm). The water samples were collected and analyzed
for physicochemical properties(dissolved oxygen, electrical conductivity, pH and temperature)
using a standard method and concentrations of heavy metalboth in fish and water, As, Cd, Cr,
Cu, Hg and Pb were analyze using Atomic Absorption Spectroscopy (AAS). The
Bioaccumulation factor and potential risk (Daily intake, health risk index and Hazard index)
from the consumption of these fish was assessed using standard methods and formula. All the
samples collected were digested using a modified procedure from the Association of Official
Analytical Chemists (AOAC) and were subsequently analyzed using Atomic Absorption
Spectroscopy. The result of the physicochemical properties and Heavy metal concentration in
water shows a significant different (P<0.05) between the C. river and M. pond. The mean of
concentration of Heavy Metals (As, Cd, Cr, Cu, Hg, and Pb) in O.niloticus, and C.gariepinus
from C. river were 2.66, 3.72, 1.84, 2.23, 3.68, 2.88, and 2.83, 3.87, 2.12, 2.66, 3.87, 2.61 mg/kg
respectively and for M.pond were 0.69, 0.98, 1.04, 0.83, 0.54, 1.00 and 0.79, 0.98, 1.16, 1.02,
0.87, 1.16 mg/kg respectively. Fishes in C. river elicited higher (P<0.05) heavy metals
concentrations compare to Fishes in M. pond. The values were all greater than themaximum
permissible limit of heavy metal in fish 0.01, 0.05, 1.5, 0.5, 0.01 and 0.3 mg/kg respectively
recommended by FAO/WHO except Cr in the control farm which is within the limit. The result
of health risk assessment shows that fishes from C. river have a higher risk from the daily intake,
health risk index and hazard index with average values greater than one (2.845) and compared to
fish in M. pond with average less than one (0.64).The study concludes that water treatment
sludge discharge in Chanchagariverhave deleterious effect on fishes and also bioaccumulate
heavy metals in the fish. The risk assessment shows that fish in C.River are contaminated with
heavy metals and could pose health risk from heavy metalContamination when consume |
