Abstract:
Consumption of fi sh contaminated with toxic heavy
metals is a threat to human health. Cadmium and arsenic are
suspected as potential risk factors for chronic kidney disease
of unknown aetiology (CKDu), which is highly prevalent
in agricultural settlements in dry zone districts of Sri Lanka
causing a severe public health crisis. Objectives of this study
were (i) to determine cadmium and arsenic levels in muscle,
liver and kidney of two edible fi shes (Nile tilapia and butter
catfi sh) from the Padaviya reservoir located in the North
Central Province, Sri Lanka where CKDu is highly prevalent
and (ii) to assess the potential human health risks associated
with the dietary exposure through edible muscle of these
fi shes. Cadmium and arsenic levels of the tissues in the two
fi sh species were determined using inductively coupled plasma
mass spectrometry. In both fi sh species, highest cadmium
levels were found in kidney (p < 0.05) whereas no signifi cant
tissue specifi c diff erences (p > 0.05) were evident for arsenic.
In the edible muscle, the maximum detected cadmium level in
Nile tilapia was 0.1 mg/kg in wet weight. However, cadmium
levels in the muscle of all Butter catfi sh were < 0.05 mg/kg.
Arsenic levels in the muscle of all Nile tilapia and Butter catfi sh
were < 0.05 mg/kg. Cadmium contents in muscle of most
fi shes and arsenic contents in all fi shes (n = 60) were within
the maximum permissible limits set by the international food
standards regulatory authorities. Based on the estimated daily
intake and target hazard quotients (< 1) for lifetime exposure,
it is highly unlikely that cadmium and arsenic contents of the
muscle meat of these fi shes would pose human health risks to
moderate level consumers.
