Accumulation of trace elements in sediment and fish species of Paira River, Bangladesh

Sediments and tissues of eleven fish species (Channa punctata, Cyprinus carpio, Heteropneustes fossilis, Colisa fasciata, Channa striata, Notopterus notopterus, Tenualosa ilisha and Corica soborna) were analyzed for (chromium (Cr), nickel (Ni), copper (Cu), arsenic (As), cadmium (Cd) and lead (Pb)). The abundance of trace elements in sediments were Cr > Ni > Cu > Pb > As > Cd and in fish species were Cu > Ni > Cr > Pb > As > Cd. The range of mean element concentration in fish species were Cr (0.44–0.97), Ni (0.45–1.1), Cu (0.91–1.5), As (0.18–0.37), Cd (0.016–0.20) and Pb (0.47–0.92 mg/kg wet weight (ww)). The concentrations of Ni, Cd and Pb in some fish species exceeded the international permissible standards suggesting that these species are not safe for human consumption. The biota-sediment accumulation factor for the studied elements in C. soborna and T. ilisha were slightly higher than the other species indicated that these species can be used as a potential bio-indicator for the contamination study of trace elements

Toxic Effects of Arsenic in Commercially Important Fish Rohu Carp, <i>Labeo rohita</i> of Bangladesh

This study was designed to elucidate the effects of arsenic (As) on the morpho-behavior, growth development and molecular mechanisms of a commercially important fish, rohu carp, Labeo rohita, in Bangladesh. Fish fry with an average weight of 387.5 ± 169.25 mg and an average length of 3.35 ± 0.37 cm were collected from a local hatchery in Mymensingh, Bangladesh and acclimatized for a week in the Department of Fisheries, University of Dhaka before starting the exposure with arsenic. Fishes were exposed for a period of 14 days with three treatments of NaAsO2, namely treatment 1(T1)—2.5 mg/L; treatment 2 (T2)—15 mg/L; and treatment 3 (T3)—30 mg/L, along with a control (C)—0.0 mg/L, with three replicates. These concentrations were determined based on the LC50 value for 96 h measured for this experiment. This study revealed remarkable morphological abnormalities and deformities in arsenic-exposed rohu carp. In fish exposed to 30 mg/L, caudal fin erosion was a frequent deformity. There was no significant difference in RNA:DNA ratio among the treatments. The overall weight of fish was decreased as the concentration of arsenic was increased. The T3 fish had a statistically significant negative weight gain (−0.05 ± 0.07 g), but the other treatments (T1 and T2) and control fish had no significant weight gain. Different types of histopathological changes were observed in the gills and intestines of arsenic-treated fish. Necrosis and severe damages were found in the secondary lamellae of gills at the highest arsenic concentration (30 mg/L). Epithelial lifting, irregular shape and damages in the gill raker were also observed in the primary lamellae of the gills for the same treatment. In this study, the expression of heat shock protein (HSP 60) and metallothionein (MT) genes was assessed by qPCR, and these genes were upregulated in different treatments compared to controls. The findings of the present study suggest that arsenic pollution significantly changes the morphology, behavior, growth, development, histopathology and molecular mechanisms of this economically important fish, rohu carp, in Bangladesh

Toxic Effects of Arsenic in Commercially Important Fish Rohu Carp, Labeo rohita of Bangladesh

This study was designed to elucidate the effects of arsenic (As) on the morpho-behavior, growth development and molecular mechanisms of a commercially important fish, rohu carp, Labeo rohita, in Bangladesh. Fish fry with an average weight of 387.5 &plusmn; 169.25 mg and an average length of 3.35 &plusmn; 0.37 cm were collected from a local hatchery in Mymensingh, Bangladesh and acclimatized for a week in the Department of Fisheries, University of Dhaka before starting the exposure with arsenic. Fishes were exposed for a period of 14 days with three treatments of NaAsO2, namely treatment 1(T1)&mdash;2.5 mg/L; treatment 2 (T2)&mdash;15 mg/L; and treatment 3 (T3)&mdash;30 mg/L, along with a control (C)&mdash;0.0 mg/L, with three replicates. These concentrations were determined based on the LC50 value for 96 h measured for this experiment. This study revealed remarkable morphological abnormalities and deformities in arsenic-exposed rohu carp. In fish exposed to 30 mg/L, caudal fin erosion was a frequent deformity. There was no significant difference in RNA:DNA ratio among the treatments. The overall weight of fish was decreased as the concentration of arsenic was increased. The T3 fish had a statistically significant negative weight gain (&minus;0.05 &plusmn; 0.07 g), but the other treatments (T1 and T2) and control fish had no significant weight gain. Different types of histopathological changes were observed in the gills and intestines of arsenic-treated fish. Necrosis and severe damages were found in the secondary lamellae of gills at the highest arsenic concentration (30 mg/L). Epithelial lifting, irregular shape and damages in the gill raker were also observed in the primary lamellae of the gills for the same treatment. In this study, the expression of heat shock protein (HSP 60) and metallothionein (MT) genes was assessed by qPCR, and these genes were upregulated in different treatments compared to controls. The findings of the present study suggest that arsenic pollution significantly changes the morphology, behavior, growth, development, histopathology and molecular mechanisms of this economically important fish, rohu carp, in Bangladesh

Widespread Use of Antibiotics, Pesticides, and Other Aqua-Chemicals in Finfish Aquaculture in Rajshahi District of Bangladesh

Aquaculture is the fastest-growing, most dynamic, and vital food-producing sector compared to other food-producing industries. However, aquaculture production is hampered by a variety of bacterial, viral, fungal, and parasitic diseases. Fish farmers routinely apply various types of aqua-chemicals, particularly antibiotics and pesticides, to reduce the disease burden. Antibiotics and pesticides are widely used to increase fish production around the world, including Bangladesh. Between March 2020 and February 2021, a survey was conducted via face-to-face interviews with fish farmers in the Rajshahi district, Bangladesh, to determine the current status of the use of antibiotics, pesticides, and other aqua-chemicals in the rearing of freshwater finfishes. Nine active antibiotics ingredients belonging to 11 trade names of antibiotics, various pesticides, numerous disinfectants, and aqua-chemicals were found to be used in finfish rearing. The renamycin (active ingredient: oxytetracycline) was most commonly used antibiotics by freshwater finfish farmers in the study areas. In case of pesticides, sumithion and timsen were found to be used mostly by fish farmers. In addition, four distinct probiotics were found to be used in aquaculture in the study areas. The present study revealed several issues related to the use of aqua-drugs in the study areas. For instance, the majority of fish farmers (88%) lacked knowledge in the use of aqua-chemicals and antibiotics, and 81% of fish farmers were unaware about the effective dosages of chemicals in fish farming. Thirty seven percent of fish farmers in the study areas reported the indiscriminate use of chemicals. Furthermore, a considerable proportion of fish farmers (72%) reported ignorance about the residual effects of the aqua-chemicals on the aquatic environment and human health. As a result, this preliminary study suggests that the use of antibiotics, pesticides, and other aqua-chemicals in aquaculture should be strictly monitored and controlled by the responsible authorities of Bangladesh. Moreover, further research needs to be expanded on the detection of residues from aqua-drugs and antibiotics in the aquaculture system, and their consequences on the ecosystem and human health

Heavy metals in sediment and their accumulation in commonly consumed fish species in Bangladesh

<p>Six heavy metals (chromium [Cr], nickel [Ni], copper [Cu], arsenic [As], cadmium [Cd], and lead [Pb]) were measured in sediments and soft tissues of eleven commonly consumed fish species collected from an urban river in the northern part of Bangladesh. The abundance of heavy metals in sediments varied in the decreasing order of Cr > Ni > Cu > Pb > As > Cd. The ranges of mean metal concentrations in fish species, in mg/kg wet weight (ww), were as follows: Cr, 0.11–0.46; Ni, 0.77–2.6; Cu, 0.57–2.1; As, 0.43–1.7; Cd, 0.020–0.23; and Pb, 0.15–1.1. Target hazard quotients (THQs) and target carcinogenic risk (TR) showed the intake of As and Pb through fish consumption were higher than the recommended values, indicating the consumption of these fish species is associated with noncarcinogenic and carcinogenic health risks.</p

Organ-specific accumulation of toxic elements in Hilsa shad (Tenualosa ilisha) from Bangladesh and human health risk assessment

Purpose: We aimed to determine the amount of some toxic elements in three organs of Hilsa shad, focusing on the possible exposure to human health through Hilsa consumption. This study was designed to determine the concentration of seven toxic trace elements (As, Cd, Cr, Cu, Ni, Pb, and Zn) in three distinct organs (n = 21) (muscle, liver, and gills) of Hilsa shad (Tenualosa ilisha) fish collected from the Bangladeshi coastal area. The samples were digested following a microwave digestion. Inductively coupled plasma mass spectrometer was used as analytical instrument. Estimated daily intakes (EDI) and target cancer risk (TR) were used to evaluate carcinogenic and non-carcinogenic risk.Results: The mean concentrations (mg/kg-wet weight) of toxic elements in different organs of T. ilisha were determined as follows: in muscle, As (4.05), Cd (0.09), Cr (0.12), Cu (0.77), Ni (0.26), Pb (0.20), and Zn (10.64); in liver, As (2.83), Cd (0.84), Cr (0.18), Cu (6.17), Ni (0.55), Pb (0.23), and Zn (30.16) and in gills, As (3.45), Cd (0.05), Cr (0.08), Cu (1.06), Ni (0.51), Pb (0.78), and Zn (35.21). The liver showed higher concentrations of most elements than that of muscle except for As. Concentration of As, Cd, and Pb in the fish were found above the food safety guidelines, while other trace element concentrations were below the permissible range for human consumption. According to EDI and TR values, there were carcinogenic and non-carcinogenic risks from exposure to total As concentration from Hilsa fish consumption.Conclusion: This study suggests that the toxic trace elements contamination levels in Hilsa fish from Bangladesh’s coastal area need to be monitored on a systematic and regular basis to ensure the safety of this food item for human consumption

Car indoor air pollution by volatile organic compounds and aldehydes in Japan

Fifty-five organic substances including volatile organic compounds (VOCs) and aldehydes present in indoor air were measured from 24 car cabins in Japan. A screening-level risk assessment was also performed. Acetaldehyde (3.81–36.0 μg/m3), formaldehyde (3.26–26.7 μg/m3), n-tetradecane (below the method quantification limit (&lt;MQL) to 47.7 μg/m3), toluene (4.23–78.3&nbsp;μg/m3), and n-undecane (&lt;MQL to 6.24 μg/m3) concentrations exceeded method detection limits in all the investigated car cabins. Ratios between indoor and outdoor concentrations revealed that most organic compounds originated from the car interior materials. Total volatile organic compound (TVOC) concentrations in 14 car cabins (58% of all car cabins) exceeded the advisable values established by the Ministry of Health, Labour and Welfare of Japan (400 μg/m3). The highest TVOC concentration (1136 μg/m3) was found in a new car (only one month since its purchase date). Nevertheless, TVOC concentrations exceeded the advisable value even for cars purchased over 10 years ago. Hazard quotients (HQs) for formaldehyde obtained using measured median and highest concentrations in both exposure scenarios for occupational use (residential time in a car cabin was assumed to be 8 h) were higher than that expected, a threshold indicative of potential adverse effects. Under the same exposure scenarios, HQ values for all other organic compounds remained below this threshold