RISK ASSESSMENT AND DETERMINATION OF ARSENIC AND HEAVY METALS IN FISH SPECIES COLLECTED FROM FISH PONDS OF KANDHKOT SINDH PAKISTAN: AN IMPACTFUL STUDY

Abstract

Assessing risks and quantifying arsenic and other toxic metals in species of fish are essential for protecting public health and ensuring the safety of seafood consumption. Using a microwave digestion technique and inductively coupled plasma optical emission spectroscopy, this study provides the first report of toxic metal concentration in two fish species found in Pakistan, Cirrhinus Mrigala (Mrigal) and Labeo Rohita (Rohu) fish species caught from Muhamadani and Baloach ponds from District Kandhkot, Sindh, Pakistan. The sediment, water, bioaccumulation factor, contamination factor, pollution load index, estimated daily intake, and Total Hazard Quotient as of potential health hazard of various heavy and toxic metals in these fish i.e., Fe, Cu, Zn, Cr, Cd and As were computed using appropriate formulas and modules. Comprehensive ways were taken to study the toxicity of these metals so that their effects on the consumers could be interpreted. The collection of fish organ samples (muscles, gills, liver) for quantitative heavy metal content as well as water and sediment from the ponds collected.

The analysis showed that metals were more accumulated in sediments and water with pollution load index for total heavy metals of sampling stations being greater than 1.9. The bioaccumulation factors for Fe, Cu, Zn, Cr, Cd, and As in fish organs, based on sediment and pond water, were 0.70, 0.30, 0.10, 0.35, 0.14, 0.10 and 0.60, 0.20, 0.01, 0.14, 0.12, 0.11 in both ponds respectively. The contamination factors were determined as 1.4 and 1.6 for Fe, 1.8 and 1.5 for Cu, 1.5 and 1.3 for Zn, 0.8 and 0.7 for Cr, 2.4 and 1.7 for Cd, and 4.1 and 4.4 for As in both ponds. Targeted Health Quotients (THQ factor) Fe, Cu, Zn, Cr, Cd and As recorded for this study were 0.11, 0.07, 0.03, 0.05, 0.03, 0.02 and 0.09, 0.06, 0.02, 0.07, 0.06, 0.01 respectively in both ponds which indicates a very low health hazard to human consumers in the study area.

The estimated daily intake and THQ values for studied metals i.e., Fe, Cu, Zn, Cr, Cd, and As ranked in order as Cr > As > Cd > Fe > Cu > Zn. Both the estimated daily intake and THQ values in samples of fish were lower than 1, which indicates a little risk to humans in the studied area. However, the elevated toxic metal content in sediments and water is likely due to the excessive waste, poor drainage infrastructure, and the overuse of poultry manure, which contribute to increasing pollution levels in these fish ponds in Kandhkot, Sindh, Pakistan.