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Background and Objective: The increasing development of agricultural and aquaculture activities along the rivers has reduced the quality of running water. The aim of this study was to evaluate Chehel-chai River water quality with national sanitation foundation water quality index (NSFWQI), Iran water quality index for surface water (IRWQISC), Canadian water quality index (CWQI).
Methods: This descriptive-analytical study, was performed on all of 7 sampling stations based on standard factors such as availability, land use type, geology and dispersion along the river, 12 water quality parameters including dissolved oxygen, fecal coliform, pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), temperature, organic phosphate, nitrate, ammonium, turbidity, total soluble solids and electrical conductivity and 5 cations (sodium, calcium and magnesium) and anion (chloride and sulfate) along the river for summer and autumn seasons 2018 (42 sample) with the standard method was measured.
Results: The amount of phosphate and turbidity increased from station 2 to downstream due to the existence of fish ponds and agricultural drainage. BOD, COD and fecal coliform values at station 6 have increased significantly with due to urban effluent output. River pollution in the summer has increased due to reduction of river flow and after station 3 (promenade) to the downstream, which is due to the entry of agricultural fertilizers and urban wastewater discharge. According to the average of IRWQISC and NSFWQI, the water quality of Chehel-chai River in the sampling station in the area of Minoodasht city (station 6) is in bad class. The CWQI index showed that the water of the Chehel-chai River is suitable for drinking and aquaculture at the border of the class, for agriculture in the bad class, and in terms of recreation and livestock use in the higher class.
Conclusion: The mean values of the above indices indicate high pollution quality class, and since this river is used for water supply for agricultural and aquaculture, management strategies are necessary.

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Background and Objective: Fish is one of the creatures which have the bio-accumulation of heavy metals. Terapon puta belongs to the order of Perciformes, is a benthic species in the waters of the Persian Gulf. This study was performed to evaluate the bio-accumulation of iron and nickel metals in the muscle of Terapon puta.
Methods: This descriptive-analytical study was performed on 30 pieces of Terapon puta caught in the Jefreh pier area of Bushehr, north of the Persian Gulf during the summer of 2019. Length (mm) and total weight (g) of fish were measured. The concentrations of iron and nickel in fish muscle tissue for human consumption were compared with international standards and calculated according to the US Environmental Protection Agency (USEPA) method for fish consumption, estimated daily uptake (EDI), and pollutant risk index (CR). After preparation, bioassay and, digestion of fish muscle with concentrated nitric acid, the concentration of iron and nickel (mg/kg) in muscle tissue was measured with ICP-OES.
Results: The mean concentrations of iron and nickel in muscle tissue of fish samples were calculated 36.08±15.72 and 0.39±0.13 mg/kg, respectively. There was a significant difference between the concentrations of iron and nickel in the muscle tissue of the Terapon puta in the sampling area (P<0.05) and these values were lower than the standard and meaningless the muscle tissue of the Terapon puta in the sampling area compared to the FDA standard. The highest concentration of metals was observed in the length class of 20-25 cm and weight class of 230-260 g. Linear regression analysis showed that a strong increase (R²=0.9) between the concentration of iron and nickel with the length and total weight of fish. The daily uptake of both metals was obtained by consuming Terapon puta muscle tissue for consumers below the USEPA reference dose. The concentration of iron in the muscle tissue of Terapon puta was lower than the international standards. Nickel concentration was more than allowable limit according to WHO standards. The carcinogenicity risk index for nickel was acceptable.
Conclusion: Concentrations of iron and nickel in Terapon puta were considered acceptable for human consumption in terms of toxicity. The risk index for Terapon puta was less than one; therefore, the consumption of Terapon puta will not cause adverse health effects for consumers.

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Background and Objective: Population growth and pollution caused by the discharge of all kinds of urban, industrial, and agricultural sewage, leachate from landfills, and surface water runoff cause an increase in pollution of water sources. The entry of heavy metals into the environment, especially aquatic ecosystems, due to entering the food chain and jeopardizing human health is one of the concerns of society. This study was conducted to determine the level of heavy metals in muscles of Cynoglossus arel and Pomadasys kaakan fishes in Boushehr coastal waters, north of the Persian Gulf.
Methods: This descriptive study was conducted on twenty pieces of Cynoglossus arel and twenty pieces of Pomadasys kaakan fishes take place from three coastal stations of Boushehr, north of the Persian Gulf, Iran during spring of 2022. The samples were randomly selected from the fish market. After preparation, bioassay, and digestion of fish muscle by concentrated nitric acid, the concentration of heavy metals including nickel, zinc, copper, lead, and cadmium (µg/g) in the muscle tissue was measured by ICP-OES device. The concentration of heavy metals in the fish muscle tissue for human consumption was compared with international standards (FAO, WHO, FDA, NHMRC, and UKMAFF). According to the method of the US Environmental Protection Agency for fish consumption, daily absorption estimates and heavy metal risk indicators were calculated.
Results: The risk potential index for both species was less than one. The daily and weekly absorption of Cynoglossus arel (zinc > copper > nickel > lead > cadmium) and Pomadasys kaakan (copper > zinc > nickel > lead > cadmium) were determined. The mean concentration of heavy metals nickel, zinc, copper, lead, and cadmium in the muscle tissue of the studied species was determined to be 1.88±0.07, 27.16±8.11, 11.55±4.12, 1.14±0.06, and 0.19±0.03 µg/g, respectively. The highest amounts of studied metals in aquatic animals were zinc > copper > nickel > lead > cadmium. The concentration of metals in the analyzed samples was lower than the international standards.
Conclusion: Regarding toxicity, the concentration of metals in Cynoglossus arel and Pomadasys kaakan was evaluated as acceptable for human consumption. In addition, the amount of risk potential and risk index for non-cancerous diseases in adults and children in fish muscle tissue was less than 1, and the consumption of this fish does not cause any problems for human health.