Status of heavy metal residues in fish species of Pakistan

The detrimental effects of heavy metals on tributaries exert pressure on water quality, Crossocheilus aplocheilus, and the well-being of human health

The escalating presence of heavy metals (HMs) in the Panjkora River water and their impact on fish pose a significant challenge to both the ecological community and human health. Consequently, a study was conducted with the primary aim of elucidating their influence on human health-related issues. To address this, the concentrations of heavy metals, including arsenic (As), cadmium (Cd), iron (Fe), manganese (Mn), lead (Pb), and zinc (Zn), in both water and the fish species Crossocheilus diplocheilus were investigated across various locations within the study area. The quantification of HMs concentration was carried out utilizing an atomic absorption spectrophotometer. The highest concentration in water was found as 0.060 mg/L for Pb and lowest for Fe, whereas the highest concentration in fish was 2.028 mg/kg for Pb and lowest for As. Human health risk associated with fish eating was evaluated by using health risk indices (HRI) for non-carcinogenic health risks and targeted cancer risk (TR) for carcinogenic health risks. The values of the health risk index (HRI) were found greater than 1 except Fe (0.0792), Zn (0.782), and Mn (0.541). The highest mean HRI > 1 was recorded for As (62.99), Cd (26.85), and Pb (10.56). This implies that fish consumption from river Panjkora is not safe up to some extent. Similarly, the TR value for As, Cd, and Pb was found 2.8 [Formula: see text], 1.6 [Formula: see text], 2.8 ×[Formula: see text] which showed cancer risk. There is a detected risk to human health associated with the consumption of fish from the Panjkora River. The government must implement adaptive measures to address this significant issue of water pollution in the study area. Additionally, there is a need for further extensive and prolonged research studies in this context.

Potentially Harmful Elements Accumulation and Health Risk Assessment of Edible Fish Tissues Caught from the Phander Valley, Northern Pakistan

This study investigated the concentrations of potentially harmful elements (PHE) in edible tissues of trout fish (Salmo trutta) in the Phander Valley, Northern Pakistan. For this purpose, fish were sampled from the Phander Valley (Gilgit River and Phander Lake). PHE concentrations in edible fish tissues (muscle, fins, and skin) were determined using atomic absorption spectrometry (AAS, AAnalyst 700, Perkin Elmer, USA). Among PHE, zinc (Zn) showed the highest concentration of 1097 μg/kg in the skin, followed by manganese (Mn) of 241 μg/kg in the muscle, and the lowest of 3.78 μg/kg for cadmium (Cd) in fins. The concentration of PHE in fish tissues of the study area was observed within the threshold limits set by the food and agriculture organization (FAO). PHE concentration of fish tissues was used for the calculation of chronic risk assessment using the chronic daily intake (CDI) and hazard quotient (HQ) indices. The highest CDI values were observed for Zn through fish tissue consumption in juveniles, followed by Mn, and the lowest for Cd in adults. The HQ values were observed less than 1 for adults through PHE consumption in fish tissue; however, that of juvenile surpassed the threshold limit through Cd consumption in all studied tissues and that of Pb in the muscle and skins only. Higher HQ values than the threshold limit could pose a potential chronic risk to the exposed community. Spearman's non-parametric correlation showed a varying degree of correlation among PHE in fish tissues and canonical discriminant analyses were used to differentiate the tissues based on PHE accumulation tendencies.

Mining Industry Impact on Environmental Sustainability, Economic Growth, Social Interaction, and Public Health: An Application of Semi-Quantitative Mathematical Approach

The mining industry plays a significant role in economic growth and development. Coal is a viable renewable energy source with 185.175 billion deposits in Thar, which has not been deeply explored. Although coal is an energy source and contributes to economic development, it puts pressure on environmental sustainability. The current study investigates Sindh Engro coal mining’s impact on environmental sustainability and human needs and interest. The Folchi and Phillips Environmental Sustainability Mathematics models are employed to measure environmental sustainability. The research findings demonstrated that Sindh Engro coal mining is potentially unsustainable for the environment. The toxic gases (methane, carbon dioxide, sulfur, etc.) are released during operational activities. The four significant environment spheres (atmosphere, hydrosphere, biosphere, and lithosphere) are negatively influenced by Thar coal mining. The second part of the analysis results shows that human needs and interests have a positive and significant relationship except for human health and safety with Sindh Engro coal mining. Environmental pollution can be controlled by utilizing environmentally friendly coal mining operations and technologies. Plantation and ecological normalization can protect the species, flora, and fauna of the Thar Desert. The government of Pakistan and the provincial government of Sind should strictly check the adaptation of environmental standards. Furthermore, the researchers should explore the environmental issues and solutions so that coal mining becomes a cost-efficient and environmental-friendly energy source in Pakistan.

Coal mine effluent-induced metal bioaccumulation, biochemical, oxidative stress, metallothionein, and histopathological alterations in vital tissues of the catfish, Clarias batrachus

In the present study, a multi-biomarker approach was used to assess the toxicity of the coal mine effluent (CME) generated at the Rajrappa coal mine on the catfish Clarias batrachus. A core of biomarkers indicative of nutritional value, oxidative stress, and histopathology was selected to illustrate the toxic effects of CME-containing different heavy metals and other toxicants. The results of metal bioaccumulation in CME-exposed fish tissues revealed the highest metal concentration in liver (1.34-297.68 mg/kg) while lowest in muscles (1.47-23.26 mg/kg) as compared to other tissues and so was the metallothionein level. The high value of bioaccumulation observed in liver, kidney, and gills reflects their affinity for metals. In addition, the values of metal pollution index (MPI) of different fish tissues further affirmed that liver followed by kidney and gills are at greater risk than brain, skin, and muscles. Significant alterations in the activity of certain enzymes (aspartate amino transferase, alanine amino transferase, alkaline phosphatase) as well as oxidative stress markers (superoxide dismutase, catalase and lipid peroxidation) were detected in the tissues of CME-exposed fish. The tissue-specific metal accumulation and increased metallothionein levels may be associated with the biochemical and physiological activity of an organ and its constitutive antioxidant defenses. The histopathological changes in the various tissues of the CME-exposed fish justify the high metal accumulation and biochemical alterations. Overall results indicate that the Rajrappa coal mine effluent is very toxic having adverse health impact on the fish and might also affect the human health when consumed.

Pathogenic microorganisms, heavy metals, and antibiotic residues in seven Korean freshwater aquaculture species

This survey was performed to estimate the levels of pathogenic microorganisms, antibiotic residues, and heavy metals in seven Korean freshwater aquaculture species including Anguilla japonica, Cyprinus carpio nudus, Oncorhynchus mykiss, Pseudobagrus fulvidraco, Semisulcospira coreana, Silurus asotus, and Trionyxs sinensis. None of the ten foodborne pathogens tested in this study were found in any of the species collected from any of the aquaculture farms. Furthermore, no banned chemicals or antibiotic residues were found in any of the species collected from any of the aquaculture farms, except enrofloxacin, which was below guideline limits (0.1 mg/kg). Finally, no species had lead, cadmium, total arsenic, or total mercury concentrations above the Ministry of Food and Drug Safety (MSDF) guidelines (0.5, 0.5, 0.1, and 0.5 mg/kg, respectively). These results ensure the safety of freshwater aquaculture species and will be useful for developing consumption advisories of freshwater fishes.