Metals Bioaccumulation in 15 Commonly Consumed Fishes from the Lower Meghna River and Adjacent Areas of Bangladesh and Associated Human Health Hazards.

Mohammad Belal Hossain,Jun Sun,Jimmy Yu,Fatema Tanjin,Shirin Akhter,Md Abu Noman,M Safiur Rahman

doi:10.3390/toxics10030139

Abstract

The lower Meghna River, the easternmost part of the Ganges Delta, faces severe anthropogenic perturbations as it receives a huge discharge and industrial effluents. To measure the metal concentrations and human health hazards, edible tissues of 15 commercially important fish species were collected from the local fish markets and the lower Meghna River, Bangladesh. Trace and heavy metals such as Pb, Cr, Cu, Zn, Mn, Fe, Hg, Ni, Ca, Co, Se, Rb, Sr, and As were detected using the Energy Dispersive X-ray Fluorescence (EDXRF) method. The hierarchy of mean metal concentrations obtained was: Fe (162.198 mg/kg) > Zn (113.326 mg/kg) > Ca (87.828 mg/kg) > Sr (75.139 mg/kg) > Cu (36.438 mg/kg) > Se (9.087 mg/kg) > Cr (7.336 mg/kg) > Mn (6.637 mg/kg) > Co (3.474 mg/kg) > Rb (1.912 mg/kg) > Hg (1.657 mg/kg) > Ni (1.467 mg/kg) > Pb (0.521 mg/kg) > As (BDL). Based on the metal concentration obtained, the carnivorous species contained more metals than omnivores and herbivores. Similarly, the euryhaline and benthic feeder fishes had more metals than the stenohalines and demersal fishes. The metal pollution index (MPI) suggested that the highly consumed fish species Tilapia (Oreochromis mossambicus) and Rui (Labeo rohita) accumulated higher metals than other fishes. Both the Targeted Hazard Quotient (THQ) and Hazard Index (HI) values for adult and child consumers were <1, indicating that consumers would not experience the non-carcinogenic health effects. Although children were more susceptible than adults, carcinogenic risk (CR) exposure of Cr for all the consumers was found in the acceptable range (10−6 to 10−4), but the CR exposure of Pb was negligible for all the consumers. The correlation, principal component analysis (PCA), and cluster analysis were conducted to identify the sources of metals identified from the fish tissue. The results indicated that the probable sources of the pollutants were anthropogenic, arising from agricultural activities, electroplating materials, and lubricants used near the study area. However, the present study showed a different metal concentration in the samples at different levels but within the threshold levels non-carcinogenic and carcinogenic health risks; hence, the fishes of the area, in general, are safe for human consumption.

Highlights

In recent decades, extensive population growth and subsequent economic development have aroused a global consciousness about heavy metals contamination owing to their persistence, non-biodegradability, and stability [1,2]
This study provides information on the levels of fourteen trace and heavy metals (Pb, Carcinogenic Risk (Cr), Cu, Zn, Mn, Fe, Hg, Ni, Ca, Co, Se, Rb, Sr, and As) in the fifteen commercial fish species collected from the local fish market of Noakhali and the lower Meghna River
Iron (Fe) showed the highest accumulation level, whereas the Pb, Cr, Ni, and As levels in the muscle tissue of the studied fish species were lower than the permitted limits suggested by the WHO and FAO

Summary

Introduction

Extensive population growth and subsequent economic development have aroused a global consciousness about heavy metals contamination owing to their persistence, non-biodegradability, and stability [1,2]. Heavy metal refers to any metallic chemical element with a relatively high density (more than 5 gm/cm3) and which is toxic or poisonous at low concentrations [3] Some of those elements (e.g., Zn and Cu) play a vital role in biological systems, but they are toxic at elevated levels. Water bodies like lake, rivers, and estuaries has been identified as a key reservoir of heavy metals due to the center of urbanization and industrialization [1,8]. Those metals discharged into the aquatic environment [9] can affect the organisms and ecosystem due to their toxicity, long persistence, and accumulative behavior [10,11], and assimilated by human consumers, resulting in health risks. Due to a poor waste management and disposal strategy, the concern is growing more seriously worldwide, and the intensity is higher in the developing countries [12–14]

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