Risk Assessment of Heavy Metals in Selected Marine Fish Species of Gadani Shipbreaking Area and Pakistan

SIMPLE SUMMARY: Protection of the coastal ecosystem from hazardous heavy metals is vital as it provides valuable habitat for numerous fish species and is a key resource for the coastal communities. Gadani shipbreaking is the third largest shipbreaking in the world, located on the coastline of Balochistan, Pakistan. The impact of this dismantling on the quality of the local fish species is still unknown. This is the first study to determine heavy metals’ content in fish and seawater of Gadani shipbreaking area. Metal accumulations in fish species both in gills and muscles ranged from 1.33 to 5.26 μg/g. Among trace metals, the level of Pb in all fish species was highest, followed by Ni, Mn, and Cd. However, all the analyzed fish species from the Gadani coast were found safe for human consumption, but there is a need for continuous monitoring of the coastal environment. ABSTRACT: Gadani shipbreaking area, located on the coastline of Pakistan, is an important fish production area. In this study, levels of four metals (Ni, Pb, Cd, and Mn) in 148 muscle and gill samples of seven fish species (Small-scale terapon, Torpedo scade, Sicklefish, Saddle grunt, Gold silk seabream, Indian mackerel, Spotted sickle fish) and seawater samples, taken from 9 sampling sites in the shipbreaking area, were determined. In addition, multiple approaches were used to assess human health risks from fish consumption. Trace metal concentration in seawater ranged from 0.05 to 1.96 mg/L in shipbreaking vicinity and 0.03 to 0.97 mg/L in the reference site (Miani Hor). However, metal accumulations in fish species ranged from 1.33 to 5.26 μg/g. Among trace metals, the level of Pb in all fish species was highest, followed by Ni, Mn, and Cd. The bioaccumulation factors (BAFs) for both gills and muscles displayed the order: Mn > Cd > Ni > Pb. Estimated daily intake (EDI) values were below the tolerable daily intake (TDI). Based on target hazard quotient (THQ), the investigated fish species were safe regarding Pb and Mn (THQ < 1), while they may cause potential risk regarding Cd and Ni (THQ > 1). After comparison with maximum permissible limits, heavy metal concentration in the edible muscle tissues of all the analyzed fish species from the Gadani coast were found safe for human consumption.