Bioaccumulation and Heavy Metal Contamination in Fish Species of the Dhaleswari River of Bangladesh and Related Human Health Implications

Essential and Non-Essential Elements Levels in Fish Species Highly Consumed in the Middle Miranda River, Brazilian Pantanal

The present study investigated the levels of As, Ag, Al, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Pb, Se, and Zn in muscle samples of six fish species (Pygocentrus nattereri, Serrasalmus marginatus, Mylossoma duriventre, Leporinus friderici, Pimelodus argenteus, and P. pantaneiro) highly consumed by local riverine and non-resident people in middle Miranda River, southern Brazilian Pantanal. Significant differences were detected for Ba, Fe, Mn, and Zn levels among the analyzed species. Pairwise comparison detected significant differences in element levels between species with similar diets, which implies that other factors, instead of species' feeding habits, could be involved in distinct levels of element bioaccumulation. Significant correlations between body size and concentrations were found for Ba in P. nattereri (moderate positive correlation), and for Mn in M. duriventre (weak positive correlation) and P. argenteus (moderate negative correlation). Levels exceeding tolerable daily intake (TDI) were found for Pb maximum concentrations in P. nattereri, M. duriventre, L. friderici, P. argenteus, and P. pantaneiro, and for Cd maximum concentration in P. argenteus. Health risk assessment indicated considerable risk only for the worst-case scenario (calculated from maximum concentrations) for all species. Adopting a Pb monitoring program in biotic and abiotic compartments in Miranda River is strongly recommended.

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.

Heavy Metals in Common Fishes Consumed in Dhaka, a Megacity of Asia: A Probabilistic Carcinogenic and Non-Carcinogenic Health Hazard

Heavy metal contamination of fish is a serious public health concern worldwide, including in Bangladesh. In this study, six commonly consumed fish species namely Hilsha (Tenualosa ilisha), Kachki (Corica soborna), Punti (Puntitus ticto), Taki (Channa punctatus), Meni (Nandus nandus), and Tengra (Mystus tengara) were analyzed for arsenic (As), cadmium (Cd), lead (Pb), zinc (Zn), copper (Cu), chromium (Cr), manganese (Mn), and nickel (Ni), by inductively coupled plasma mass spectrometry. The fish samples were collected from wholesale markets in Dhaka city, the main business hub of Bangladesh where the fishes converged from countrywide and are redistributed to the whole city. The metal concentration varied among the studied fish species. Hilsha, the national fish of Bangladesh, contained the highest As among the other fishes of this study, whereas Zn, Cd, Cu, Mn, and Ni were the highest in Kachki, and Pb and Cr were the highest in Tengra. The probable source of metal accumulation in the fish species may be the river or marine water that can be contaminated by industrial waste, pesticide, and/or fertilizer use in agriculture and/or commercial fish feeds. All analyzed fish species showed serious heavy metal pollution, having high average pollution load index (APLI) values (> 1). The estimated daily intake (EDI) values for the metals were lower than the maximum tolerable daily intake (MTDI). The hazard index (HI) for all the fish species was above 1 for adults, showing non-carcinogenic health risks. The target carcinogenic risk (TCR) values were below the acceptable limit (10-4) for most of the metals, indicating safe for consumption with respect to the risk of cancer.

Seasonal Variation and Association of Heavy Metals in the Vital Organs of Edible Fishes from the River Jhelum in Punjab, Pakistan

The toxic effects of heavy metals are drastic, including accumulation. Fish species are important bio-indicators of heavy metal pollution in aquatic bodies. The current study aimed to assess the seasonal variation of heavy metals in the vital organs of mostly consumed fishes in River Jhelum, Pakistan. Samples of fish, including Wallago attu (Malhi), Rita rita (Khagga), and Mystus seenghala (Singhari), were collected from four different sites, i.e., Khushab, Muhammad Wala (M. Wala), 8.R.D and Rasool barrage during summer and winter seasons. Heavy metals such as iron (Fe), lead (Pb), chromium (Cr), cobalt (Co) and Cadmium (Cd) were estimated through acid digestion and spectrometric analysis. Results showed a significantly higher (P < 0.05) amount of these metals in the liver, followed by the kidneys of fish species. There were seasonal variations in the absorption of these metals as well. Cr (11.71) and Fe (58.66) were detected in higher amounts in Khagga which showed the greatest affinity for certain metals in some cases. In contrast, Singhari showed the greatest affinity to other metals in other cases. Comparative analysis revealed that there was a highly significant (P < 0.05) difference for the accumulation of almost all metals in both seasons and summer had the highest concentration of Cd, Pb, Co, Cr and Fe as compared to winter in all four sampling stations in the case of kidney and liver of all the three fishes. Elevated levels of heavy metals were detected in the summer due to increased temperature. Heavy metals found in the River Jhelum may demonstrate that metals can significantly affect the fish species.

The release of polypropylene plastic from disposable face masks in different water conditions and their potential toxicity in human cells

Due to their extensive use during and after the COVID-19 pandemic, many disposable face masks are irresponsibly deposited into the water environment, threatening the health of people living nearby. However, the effects of water conditions on the degradation and potential hazards of these masks are generally unclear. This paper entailed the release and cellular toxicity of micro/nano plastics from disposable face masks once discarded in different waters, including soil water, river water, and tap water, with deionized (DI) water as control. At first, polypropylene (PP) was confirmed to be the major component of disposable face masks with Raman and Fourier transform infrared (FTIR) techniques. To monitor the release rate of PP from masks, a silver nanoparticle (AgNP)-based surface-enhanced Raman scattering (SERS) method was established by employing the unique Raman fingerprint of PP at 2882 cm-1. During 30-d incubation in different waters, the release rates of PP, sizes of PP aggregates, length of fibers, and proportions of plastics smaller than 100 nm were in the order of soil water > river water > tap water > DI water. All the obtained PP exhibited significant toxicity in human lung cancer (A549) cells at concentrations of 70 mg/L for 48 h, and the ones obtained in soil water exhibited the most severe damage. Overall, this paper revealed that environmental waters themselves would worsen the adverse effects of disposable face masks, and the key compounds affecting the degradation of masks remain to be clarified. Such information, along with the established methods, could be beneficial in assessing the health risks of disposable face masks in different waters.

Assessment and Bioaccumulation of Heavy Metals in Water, Fish (wild and Farmed) and Associated Human Health Risk

Worldwide, anthropogenic activities are causing the natural environment and aquaculture systems to become heavily contaminated with heavy metals, which can lead to consumer's health problems. In the current study, wild and farmed fish (n = 30) and water samples (n = 6) have been collected from the Chashma barrage and fish farm to assess the heavy metals concentration, i.e., Cu, Cd, Pb, Zn and Cr, in the water and some important organs (gills, liver, muscle, brain and bones) of wild and farmed fish (Labeo rohita) using Graphite furnace Atomic absorption spectrometry. Bioaccumulation factor and human health risk assessment were calculated to measure the health status of both fish and humans. Results show that in wild and farm fish's gills, muscles and bones, the trend of the heavy metals was Zn > Pb > Cu > Cd > Cr. On the other hand, the brain and liver show Zn > Cu > Pb > Cd > Cr trend. Comparatively, the heavy metals concentration was mostly higher (P < 0.05) in wild fish. Further; in both fish habitats (water) the heavy metals (Cd and Pb) concentration was higher than the WHO standard level, while in the body, Cd was higher (P < 0.05) in all studied organs except the muscle, Cr was only lower (P > 0.05) in muscle and brain. Pb was higher (P < 0.05) in all studied organs of both fish. Bioaccumulation of heavy metals was mostly higher (P < 0.05) in wild fish than in farmed. EDI and THQ were higher in wild fish, but the HI value was lower than 1 for both fish. Moreover, the PCA analysis suggests a positive correlation between heavy metals concentration in fish organs and the water of both fish (wild and farmed). Results indicated that farmed fish showed less potential risk to humans than wild fish.

Assessment of Essential and Potentially Toxic Elements in Water and Sediment and the Tissues of Sciaena deliciosa (Tschudi, 1846) from the Coast of Callao Bay, Peru

The lorna drum Sciaena deliciosa is a coastal demersal species and one of the underlying artisanal fisheries in some areas of Peru, and is also a source of protein for Peruvian coastal dwellers. The investigation addresses concern about the environmental impact on this fish species and the potential risks to human health through the consumption of contaminated seafood. This research endeavors to assess the concentration of potentially toxic and essential elements in the muscle and liver tissues of S. deliciosa, in addition to the presence thereof in water and sediment capture areas on the coast of Callao, Peru. The study revealed that, in water samples, Ag, Ni, and Zn exceed Peruvian standards, but were below international standards, and Ba, P, Se, and Sn exceed international standards. In the sediments, As, Cd, Pb, Fe, and Zn were above international standards. In the fish, S. delicious muscle demonstrated As, Hg, and Pb exceeding at least one international standard. In the liver, As, Hg, Pb, and Cu exceed international standards. The study approach increased accuracy in risk assessments, offering crucial insights into the interplay between heavy metal pollution, water quality, and animal health, informing risk management strategies. Future studies can explore the long-term effects of heavy metal exposure on different organisms and consider their cumulative impact on health.

Lab-on-a-Drone: remote voltammetric analysis of lead in water with real-time data transmission

The present work describes a laboratory-on-a-drone (Lab-on-a-Drone) developed to perform in situ detection of contaminants in environmental water samples. Toward this goal, the system was mounted on an unmanned aerial vehicle (UAV) (drone) and remotely controlled via Wi-Fi to acquire a water sample, perform the electrochemical detection step, and then send the voltammetry data to a smartphone. This Lab-on-a-Drone system was also able to recharge its battery using a solar cell, greatly increasing the autonomy of the system, even in the absence of a power line. As a proof of concept, the Lab-on-a-Drone was employed for the detection of Pb2+ in environmental waters, using a simple electrochemical cell containing a miniaturized screen-printed boron-doped diamond electrode (SP-BDDE) as a working electrode, an Ag/AgCl as a reference electrode, and a graphite ink as a counter electrode. For quantification purposes, analytical curves were constructed covering a concentration range from 1.0 μg L-1 (4.83 nmol L-1) to 80.0 μg L-1 (386.10 nmol L-1), featuring a detection limit of 0.062 μg L-1 (0.30 nmol L-1). The Lab-on-a-Drone was applied to monitor a water reservoir in the Metropolitan Region of Recife, Brazil. To evaluate its performance regarding accuracy and precision, a reference method based on inductively coupled plasma optical emission spectrometry (ICP-OES) was applied, and the results obtained by both methods showed no statistical differences (t-test at 95% confidence level, n = 3). These results represent the first demonstration of the capabilities of an adapted UAV for the quantification of electroactive environmental contaminant using voltammetry, with real-time data transmission. Thus, the Lab-on-a-Drone makes it possible to reach difficult-to-access environmental reserves and to monitor potentially polluting activity in distant water bodies. Thus, this tool can be used by governments and non-profit organizations to monitor environmental waters using fast, low-cost, process autonomy with accurate and precise data useful to decision making.

Prediction of Hazardous Effect of Heavy Metals of Point-Source Wastewater on Fish (Anabas cobojius) and Human Health

Aquatic ecosystems are exceedingly contrived due to industrial dispenses, as a huge amount of toxicants especially heavy metals are released, causing drastic effects on aquatic lives and the human body. This study was performed to assess the quality of point-source industrial wastewater at varying percentage levels and their subsequent hazardous effect on fish (Anabas cobojius) and human health. The perceived value revealed that water quality parameters declined with the increase of wastewater concentration and trace metal evaluation index (TEI) ascertained a high level of water pollution due to Cr, Mn, Fe, Co, Ni, Cu, Zn, and As content for all percentages of wastewater. Concentration of wastewater and culture treatment duration largely impacted on fish mortality rate, body dis-pigmentation, mucus secretion rate, coagulation of mucus all over the body, and accumulation of heavy metals by fish samples. Metal pollution index (MPI) indicated low contamination of fish by the measured elements. Zn and Hg exceeded the threshold limit of target hazard quotient (THQ > 1) and contributed significantly to non-carcinogenic health implications for both the population group. Maximum hazard index in adults and children was observed to be 10.638 and 16.548 for 100% effluent at 96-h exposure period and the overall HI value manifested a very high to medium significant health effects regardless of age. Carcinogen Pb showed insignificant risk but Cr and Ni showed extremely high to medium-high risk for both the population group, and children were found more vulnerable receptors than adults. However, source of heavy metals in wastewater and fish samples stipulated anthropogenic sources.

A Probabilistic-Deterministic Approach Towards Human Health Risk Assessment and Source Apportionment of Potentially Toxic Elements (PTEs) in Some Contaminated Fish Species

Contamination of fish species with potential toxic elements (PTEs) has caught the prime attention globally including Bangladesh. The present study enlightened on the accumulation, origin, and associated health implications of Mn, Fe, Cu, Zn, As, Hg, Pb, and Cr in ten varieties of fish species collected from the heavily polluted river Buriganga. Levels of PTEs in the studied fish species were found within the legislative value suggested by the World Health Organization (WHO) and Federal Environmental Protection Agency (FEPA) except for Fe, Cu, Zn, and Hg and can be assembled as Zn > Fe > Cu > Mn > Cr > Hg > As > Pb. The origin of PTEs in fish species apportioned mostly anthropogenic coupled with natural sources. Among the anthropogenic sources, industrial wastewater, recycling of leaded and lithium-ion batteries, metallurgical industries, shipyards, tannery, cosmetics, and chemical industries are the major contributors. This study identified children are exposed to As and Zn as their estimated targeted hazard quotient (THQ) value exceeded the threshold limit of safety, whereas adults are exposed to As only. The estimated, hazard index (HI) for children was found more than four times of adults; however, both the population groups are in vulnerable situation considering HI value (HI > 1), indicating possible non-carcinogenic health risk. Moreover, cumulative cancer risk TCR appraised that all the fish species exceeded the threshold limit of > 1E-03 for children and > 1E-04 for adults, which are level VII and level V contamination state for child and adult, respectively, and manifested consumption of the studied fishes arises a high probability for lifetime cancer risk.

Remediation of Chromium (VI) from Contaminated Agricultural Soil Using Modified Biochars

Chromium (Cr) is a potentially toxic metal occurring in the soil as a result of natural and anthropogenic activities and is mainly found in Cr³⁺ and Cr⁶⁺. The hexavalent chromium has toxic effects on plants, animals, humans and microorganisms depending on exposure level, duration and doses. Biochar is a stable carbon-based material that has been widely documented to immobilize metals in contaminated soils and for soil remediation effectively. The present 90 days incubation study was conducted to investigate the potential use of rice stubble and sawdust-derived modified biochars on Cr⁶⁺ remediation and their effects on nutrient availability. Among the treatments, modified rice stubble biochar (RSB-M) contained the highest surface area, pore volume and CEC. The unmodified and modified biochars significantly increased soil pH, EC, CEC, and N, K availability ((p < 0.001)). Statistical analysis showed that modified rice stubble (RSB-M) and sawdust biochars (SDB-M) significantly reduced the Cr⁶⁺ with incubation days compared to unmodified biochars, possibly due to the greater porous structure and various functional groups. The submerged incubation condition also greatly impacted Cr⁶⁺ reduction since a gradual decrease (up to ~70 mg kg-1 of Cr⁶⁺) was observed in control treatments. Therefore, applying modified biochars is imperative to alleviate Cr⁶⁺ polluted soils and improve soil fertility.

Concentrations of trace metals in Siganus javus captured in Negombo estuary, Sri Lanka: Human health risk assessment through dietary exposure

Concentrations of aluminium, cadmium, chromium, lead, nickel and zinc in muscle and liver of a marine fish in Indo-Pacific region, Siganus javus captured in Negombo estuary were evaluated and potential human health risks associated with dietary exposure were assessed. Of the six metals analyzed, zinc was the most abundant metal in both tissues. No significant differences were found between muscle and liver with respect to cadmium and lead concentrations whereas concentrations of other metals were higher in liver compared to muscle. In human health perspective, estimated target hazard quotients for cadmium and lead were greater than the threshold of one indicating potential non-cancer health risks to heavy consumers. Estimated excess cancer risk of cadmium indicate carcinogenic health risks associated with their consumption even at moderate meal frequencies. The results revealed that consumption of S. javus from the estuary needs to be limited concerning non-cancer and cancer risks to human health.

Pollution and Potential Ecological Risk Evaluation Associated with Toxic Metals in an Impacted Mangrove Swamp in Niger Delta, Nigeria

Anthropogenic activities along coastal areas have contributed to the unwarranted discharge of toxic metals into mangrove swamps, posing risks to marine deposits and ecological environments. In this research, we studied the Isaka−Bundu tidal swamp area in the Niger Delta, which is an impacted mangrove creek located along the Bonny river, exposed to pollution pressures. The ecological risks (Er) of toxic metals in the sediments and water of the Isaka−Bundu tidal mangrove swamp followed a decreasing order (Cu > Zn > Cd > Cu > Pb > As), according to our results, while the potential ecological risk index (PERI) of the toxic metals in the sediments and water of the Isaka−Bundu tidal mangrove swamp can be said to have a very high ecological risk (PERI ≥ 600). The sediment pollution load index (PLI) was higher than 1 in all three analyzed stations, suggesting extremely toxic pollution. The enrichment evaluation shows that the studied stations have a moderate potential ecological risk of Cd, with the enrichment value for Pb showing low potential ecological risk. Our study shows that the Isaka−Bundu tidal mangrove swamp has a significant level of toxic metal pollution, which is evidence of the illegal activities performed in the Niger Delta.

Pollution status of heavy metals and metalloids in Chinese lakes: Distribution, bioaccumulation and risk assessment

Due to intensive human activities, most of Chinese lakes are suffering from the pollution of heavy metals and metalloids. Previous studies on heavy metals and metalloids in Chinese lakes were limited to a few lakes and mainly focused on sediments, to date the knowledge on heavy metals and metalloids in multiple media of Chinese lakes from a national perspective is scarce. We collected the data of nine heavy metals and metalloids including Copper (Cu), Cadmium (Cd), Lead (Pb), Mercury (Hg), Arsenic (As), Chromium (Cr), Nickel (Ni), Zinc (Zn), and Manganese (Mn) in water, surface sediments, and fish of 87 Chinese lakes sampled in the period from 2009 to 2019 from the literature, summarized the distribution of heavy metals and metalloids, evaluated their pollution, and apportioned their sources from a national perspective. Concentration of individual heavy metal and metalloid in water, surface sediments, and fish in Chinese lakes was in the ranges of 0.0080-282 μg/L, 0.020-33858 μg/g, and 0.00030-207 μg/g, respectively. 5.6 % and 33.3 % of lake water were polluted by Cd and As. 88.2 %, 78.6 %, and 66 % of lake sediments were polluted by Cd, Hg, and As. 35.3 %, 11.3 %, 52.4 %, and 12.8 % of Cd, Pb, As, and Cr concentrations in lake fish exceeded the food limits. Concentrations of heavy metals and metalloids in fish viscera were higher than those in other organs. Higher partition coefficient and bioaccumulation factors were found for Pb and Cd, Hg and Zn, respectively. Concentrations of heavy metals and metalloids in both water and sediments of lakes in eastern China were higher than those in western China. Concentrations of heavy metals and metalloids in both lake water and sediments of urban lakes were higher than those of rural lakes. Lakes with extremely high ecological risk of heavy metals and metalloids were mainly located in central China and eastern China. Pollution of heavy metals and metalloids in Chinese lakes was closely correlated with regional economic development. Heavy metals and metalloids in Chinese lakes were mainly derived from industrial, domestic, and mixed discharges. Cd and Hg were selected as the heavy metals for priority control in Chinese lakes.