Assessment of human health hazard associated with heavy metal accumulation in popular freshwater, coastal and marine fishes from south-west region, Bangladesh

Exploring Potential Human Health Risks Linked to Heavy Metal(Loid)s in Dietary Fishes: Utilizing Data-Driven and Computational Modelling Approaches

There are significant concerns about the risks to human health posed by metal(loid) contamination in dietary fishes in Bangladesh. Therefore, this study aimed to evaluate heavy metal(loid) contamination in fish and their associated health risks using published data from 2000 to 2022. Additionally, the safe limit of fish consumption was estimated using the target hazard quotient (THQ) followed by computational modelling and artificial neural networks (ANN). Results showed that freshwater and herbivorous fishes pose the least non-cancer risks, whereas saltwater and carnivorous fishes pose the highest non-cancer risks to Bangladeshi consumers. However, freshwater and omnivorous fish consumption pose the highest cancer risks compared to all studied metal(loid)s. In particular, among the heavy metal(loid)s, As, Cr, Hg, and Ni pose significant cancer and non-cancer risks to Bangladeshi consumers. On the contrary, the ANN and Decision tree regression (DTR) characterized the dataset, simulation model, or data testing condition, reaching 94.7% accuracy and allowing us to measure the safest fish consumption limit. The herbivorous fishes are less contaminated and allow greater consumption (175.09 g day-1). Contrarily, the allowable intake rates of carnivorous and omnivorous fishes are 153.05 and 168.63 g day-1, respectively. Besides, the safe consumption rate of saltwater fishes was 156.51 g day-1, which was lower than freshwater (180.59 g day-1) and euryhaline fishes (182.17 g day-1). Therefore, this study will assist fish consumers in selecting less contaminated fish, ensuring safe consumption levels, and ultimately reducing health risks associated with metal(loid) contamination in fish.

Heavy metal contamination in freshwater habitats impairs the growth and reproductive health of wild spotted snakehead Channa punctata (Channidae) in Bangladesh

Heavy metal bioaccumulation in aquatic organisms of open water aquatic ecosystems was detected globally, including Bangladesh. This study evaluated the hypothesis of whether heavy metal contamination in aquatic habitats impacts fish growth and reproduction using wild Channa punctata as an experimental animal. The growth and reproductive health of a wild freshwater fish, C. punctata, collected from five freshwater habitats, were assayed with heavy metal bioaccumulation. Atomic absorption spectrometry detected the bioaccumulation of cadmium (Cd), chromium (Cr), mercury (Hg), and lead (Pb) in the muscle of C. punctata. Cd, Cr, and Pb concentrations were the highest in the specimen collected from the Turag River and the lowest in the Dharla River. The highest concentration of Hg was found in C. punctata specimens collected from the Karatoya River (0.093 ± 0.004 mg/kg). The length-weight relationship and condition factor of C. punctata indicated a negative allometric growth pattern (b < 3.0) and poor wellness (F < 1.0) in all the stocks except Dharla River. We estimated the size at first sexual maturity (L50), ova diameter, fecundity, and gonadosomatic index (GSI) to assess reproductive health and determined the correlation with heavy metal bioaccumulation. We found that higher bioaccumulation of heavy metal impairs the reproductive health of C. punctata by lowering spawning performance. This study showed that heavy metal bioaccumulation impaired fish's growth and reproductive health, potentially affecting future recruitment and fishery sustainability.

A Comprehensive Assessment of Health Risks Associated with Heavy Metal Through Ingestion of Two Predominant Fish Species in a Developing Country

The existence of heavy metal pollutants in fish within aquatic ecosystems presents a threat to human health due to trophic shift. This research sought to identify the concentrations of cadmium (Cd), arsenic (As), copper (Cu), lead (Pb), and chromium (Cr) in two economically significant cultured fish species, pangus (Pangasius hypophthalmus) and catla (Labeo catla), which were sourced from key fish markets in Khulna, Bangladesh. Nevertheless, there has been a scarcity of studies addressing the metal concentrations in these species within this region. To evaluate the levels of trace elements, atomic absorption spectrophotometry (AAS) was employed following the acid digestion of the samples. The concentrations of Cd, As, Cu, Pb, and Cr were observed as 0.372, 0.232, 0.741, 0.758, and 1.356 mg/kg in pangus and 0.395, 0.297, 1.175, 0.616, and 0.959 mg/kg in catla fish, respectively. The concentrations of Pb and Cd exceeded the maximum permissible limits established by the FAO and WHO. Apart from Cu, the estimated daily intakes (EDI) for both seasons and age groups exceeded the recommended daily allowance (RDA), indicating that other trace elements could be detrimental to human health. In contrast, the calculated hazard index (HI) and total hazard quotient (THQ) remained below 1, suggesting that the fish examined would not pose health risks to adults but the HI value for children surpassed the acceptable limit. Moreover, Cd (for adult group) and Cd and Cr (for children group) surpassed the acceptable range for carcinogenic risk (CR), and the total carcinogenic risk (TCR) exceeded the permissible limit for both groups. This study concluded that studied fishes may represent a health risk for consumers, underscoring the necessity for ongoing monitoring of trace elements in other fish species within that catchment area.

Impact of anthropogenic activities and the associated heavy metal pollution in Sundarbans waterways: threats to commercial fish and human health

The exposure of fish to heavy metals is a significant concern for human health and natural ecosystems. Despite being a critical issue, the extent of contamination in tropical fish from developing countries like Bangladesh remains somewhat unexplored. In this study, ten economically vital fish species (Osteogeneiosus militaris, Arius gagora, Harpadon nehereus, Mugil ephalus, Pseudapocryptes elongates, Apocryptes bato, Labeo bata, Tenualosa toil, Notopterus notopterus, and Pampus chinensis) from the Pasur River, Bangladesh, were analyzed by atomic absorption spectrometer for the concentrations of four concerned heavy metals, viz., As, Cr, Cd, and Pb, and the associated human health risks. The mean concentrations (mg/kg) followed the order of As (3.30 ± 1.43) > Pb (2.32 ± 0.73) > Cr (0.63 ± 0.29) > Cd (0.37 ± 0.24). Additionally, the bioaccumulation factor of the metals in the investigated fish species followed a decreasing trend of As (824.75) > Cr (781.25) > Cd (744) > Pb (385.83). While most species fell below the minimum bioaccumulation line, a few exceptions were noted for some species specific to metals. Health risk assessments indicated no significant carcinogenic and non-carcinogenic risks for both children and adults, although children exhibited greater vulnerability to both types of health effects. Multivariate analysis and local perceptions supported the conclusion that heavy metals primarily originated from anthropogenic sources related to development activities adjacent to the riverine areas.