Trace metals and nutrient analysis of marine fish species from the Gwadar coast.

Trace metals are naturally occurring metals found in very small concentrations in the environment. In the context of fish flesh, metals such as copper, calcium, potassium, sodium, zinc, iron, and manganese are absorbed by fish and play vital roles in various physiological functions. However, if these metals exceed the recommended limits set by WHO/FAO, they are termed 'toxic metals' due to their harmful impacts on both the fish and its consumers. Therefore, the present study aims to analyze the levels of protein, lipids, and certain metals-Aluminum (Al), Sodium (Na), Zinc (Zn), Titanium (Ti), Iron (Fe), Copper (Cu), Potassium (K), and Calcium (Ca) in three commercially important marine fishes i.e. Rastrelliger kanagurta, Sardinella abella, and Otolithes ruber. The study also aims to assess their potential impact on human health. The macro-Kjeldhal method and Soxhlet apparatus were used to estimate protein and lipid contents, while atomic absorption spectroscopy (AAS) was used to estimate trace metals found in fishes. The study found that these fish species are valuable sources of protein, lipids, and certain essential minerals. The protein content (CP) in these three species ranged from 63.35 to 86.57%, while lipid content was from 21.05 to 23.86%. The overall results of the trace metal concentrations analyzed in the present study revealed that Aluminum (Al), Sodium (Na), Zinc (Zn), Titanium (Ti), Copper (Cu), Potassium (K), and Calcium (Ca) were found in low concentration or traces and also within suitable ranges as set by WHO/FAO. However, Iron (Fe) was absent in all three species. Moreover, both copper and potassium were found in all three species, while Zinc was present in Rastrelliger kanagurta and Sardinella abella, calcium in Sardinella abella, and sodium in Otolithes ruber only. Titanium was recorded for the first time in S. abella. However, the total health risk assessment associated with these fish food consumption was measured by THQ and TTHQ and found to be less than 1, which shows no potential risk related to trace metals found in these fishes on human health upon their consumption. In conclusion, these commercially important marine fish species were found valuable sources of protein, lipids, and essential trace minerals that are necessary for human health. Thus, the current study provides useful information for the local population to make informed decisions about their daily diets and highlights the importance of sustainable fishing practices to maintain these valuable marine resources by periodical monitoring of their ecosystem.

Impacts of Some Trace Metals in Cyprinus carpio (Linnaeus, 1758) and Tor soro (Valenciennes, 1842) on Human Health.

Although fish are rich sources of various trace metals in their bodies, when these metals exceed health safety limits, it becomes a global concern. Fish exposed to trace metal pollution in their aquatic ecosystems can lead to bioaccumulation and transfer to consumers. Monitoring trace metal contamination of fish food is crucial because they can reach humans through the aquatic food chain, resulting in health problems. Therefore, a first attempt was made for the analysis of trace metals in two cyprinid fish species, namely Cyprinus carpio (Common carp) and Tor soro (Mahseer), which were abundantly found in Khanozai Dam and assessing their potential health impacts when consumed by humans. A total of 200 fish specimens were collected from this area. These specimens were divided equally between the two carp species, with 100 individuals from each species. The fish specimens were collected over 12 months, from June 2020 to May 2021 to determine the concentration of some trace metals, i.e. Manganese (Mn), Calcium (Ca), Iron (Fe), Potassium (K), and Zinc (Zn), Sodium (Na), Phosphorus (P), Magnesium (Mg), and Chlorine (Cl) using a Flame Atomic Absorption Spectrophotometer with a multi-element hollow cathode lamp. The obtained results from the trace metal analysis of Cyprinus carpio and Tor soro in this study revealed that both calcium and phosphorus were present in higher concentrations. However, iron, manganese, and zinc were not detected in both species. Additionally, magnesium was also not detected in C. carpio. For Cyprinus carpio, the arrangement was Ca > P > K > Na > Cl, while for Tor soro, it was Ca > P > Na > K > Cl > Mg in decreasing order. The health risks associated with fish consumption were assessed using factors like estimated daily intake (EDI), Target Hazard Quotient (THQ), and Total Target Hazard Quotient (TTHQ). The THQ values for all analyzed trace metals in both carp species exceeded the maximum value of 1.0, except for Cl in Tor soro. This suggests the potential for various health-related diseases in regular consumers due to their elevated levels. In both species, the TTHQ factor also surpassed the standard value of 1.0, indicating an acute health risk for humans. Although EDI values did not surpass the recommended daily allowance (RDA), continuous consumption of these contaminated fish from this area could lead to severe health complications. Therefore, these results strongly indicated that the elevated levels of trace metals found in the highly abundant cyprinid species of Khanozai Dam could pose serious health-related issues for the local inhabitants.

Effects of "defective" plasmonic metal nanoparticle arrays on the opto-electronic performance of thin-film solar cells: computational study.

This computational study investigates the effects of common defects that occur while fabricating arrays of plasmonic metal nanoparticles (NPs) on the absorbing layer of the solar cells for enhancing their opto-electronic performance. Several "defects" in an array of plasmonic NP arrays on solar cells were studied. The results demonstrated no major changes in the performance of solar cells in the presence of "defective" arrays when compared to a "perfect" array with defect-free NPs. The results indicate that relatively inexpensive techniques may be used to fabricate "defective" plasmonic NP arrays on solar cells and still obtain a significant enhancement in opto-electronic performance.

Bioaccumulation of heavy metals in the different tissues of Mackerel scad, Decapterus macarellus (Cuvier, 1833) collected from Karachi and Gwadar Coasts of Pakistan.

Introduction: Among other aquatic animals, fish can also accumulate a large number of toxic metals in their various body organs, which may enter in the human body and cause serious health issues. Therefore, the basic aim of this study was to observe the level of some heavy metals (i.e., Pb, Fe, Cu, Cd, Cr) found in the different tissues of Decapterus macarellus collected from the Karachi and Gwadar coasts of Pakistan. Methods: About 200 fish samples of five different size groups of Decapterus macarellus were collected from Gwadar and Karachi fish harbors during April to September 2020. Total 10 samples of each size group i.e., S1, S2, S3, S4 & S5 were collected from each coast. Heavy metals were analyzed in fish samples by using the atomic absorption spectrophotometer (AAS). Results: The overall results revealed that some metals like Cu, Pb, Cd & Cr contents were high in the stomach, while less in the muscles. Whereas, the concentration of Fe was found to be high in the liver, while low in skin of fish. The average values of bioaccumulation of these heavy metals (BAF) were found in decreasing order of Cu > Cd > Fe > Cr > Pb. In this study, except Cd and Cr, all metals were found within the permissible limits. Both sediment and water from the selected site areas were also analyzed to observe their pollution levels in the order of; sediment > water > fish tissues. Conclusion: Thus, it was concluded that the Karachi environment was much more polluted than the Gwadar environment because it is in an industrial unit and a busy sea site for trade. Moreover, consuming muscles from this species is safe for human health except for iron toxicity, but the use of the liver is not beneficial for all selected metals. Thus, the present work will also be helpful to monitor these toxic metals in a food chain and maintain a healthy life, and reduce all kinds of health risks associated with them.

Risk factor analysis for the prevalence of gastrointestinal parasites found in large ruminants in Lower Dir Khyber Pakhtunkhwa Pakistan.

The present study was designed to investigate the prevalence of gastrointestinal (GI) parasites in cattle and buffaloes of Lower Dir Khyber Pakhtunkhwa, Pakistan. The presence of the eggs, cysts, and oocysts of GI parasites in fecal samples were detected using direct smear methods and concentration techniques including floatation, centrifugation, and sedimentation. Identification of recovered fecal stages were determined by morphology using size and appearance of the recovered eggs, cysts, and oocysts. A total of 314 fecal samples were collected from the different Tehsils (Administrative Districts) and analyzed through microscopy. A higher prevalence was observed in the buffalo than the cow population. A total of 184 samples were positive for GI parasites of which 109/196 (55.61%) were from cattle, whereas 75/118 (63.55%) were from buffaloes. The minimum number of strongyle eggs detected in all the samples were 136.39 eggs/g (EPG). The mean EPG in cattle was 143.30 and 122.56 in buffaloes. The open-source water prevalence of GI parasites was higher than the other sources in cattle and the second highest after tap water in buffaloes. The seasonal prevalence of GI parasites ranged from 32.39% (23/71), in spring to 68.8% (86/125) in summer in cattle. In was For buffaloes the infection prevalence was 52.94% (27/51) and 71.64% (48/67) in spring and summer, respectively. Gastrointestinal parasites are a serious problem in cattle and buffaloes in the lower district of Dir Khyber Pakhtunkhwa Pakistan. In general, the burden of parasitic infection was low in most animals that received previous anti-parasitic treatment.