A systematic review of the concentration of potentially toxic elements in fish from the Persian Gulf: A health risk assessment study

Introducing bio-indicator fish of the Persian Gulf based on health risk assessment of 27 commercial species

BACKGROUND

The increasing consumption of seafood may bring health risks. It will be especially important for the people living along the coasts who are highly dependent on seafood for food and income.

METHODS

In this research, a comprehensive health risk assessment was performed on 27 species of high-consumption commercial fish sampled from stations located in Hormozgan province within the Northeast Persian Gulf. Concentrations of trace metals and their health risk were investigated.

RESULTS

Spatial distribution of trace metals in commercial fish showed central stations including Kong and Greater Tonb have higher concentrations of all trace metals except Pb. Some metals showed a significant correlation between concentrations. Our finding indicated the average concentration of all trace metals except Ni in all species was below the concentrations proposed by WHO/FAO/USEPA. EDI for all metals in all species in both adult and child age groups was lower than its RfD (oral reference dose of trace metal) showing the daily consumption of these fish does not pose any health risk and implicates seafood consumption guidelines or policies. Values of THQ for each metal and HI for all metals were lower than 1 in all commercial fish indicating the lack of non-cancerous health risk through the long-term consumption of these fish. The research found potential health risks associated with the consumption of these fish, specifically related to the metals Cr, Ni, and Cd.

CONCLUSION

In total, health risk indices proposed eight fish as bio-indicator species of the Persian Gulf. The findings emphasize the risk management of commercial fish consumption, especially bio-indicator species, in Hormozgan province, the Northeast Persian Gulf.

Nanotechnology-based analytical techniques for the detection of contaminants in aquatic products

Food safety of aquatic products has attracted considerable attention worldwide. Although a series of conventional bioassays and instrumental methods have been developed for the detection of pathogenic bacteria, heavy metal residues, marine toxins, and biogenic amines during the production and storage of fish, shrimp, crabs et al., the nanotechnology-based analyses still have their advantages and are promising since they are cost-efficient, highly sensitive and selective, easy to conduct, facial design, often require no sophisticated instruments but with excellent detection performance. This review aims to summarize the advances of various biosensing strategies for bacteria, metal ions, and small molecule contaminants in aquatic products during the last five years, The review highlights the development in nanotechnologies applied for biorecognition process, signal transduction and amplification methods in each novel approach, the nuclease-mediated DNA amplification, nanomaterials (noble metal nanoparticle, metal-organic frameworks, carbon dots), lateral flow-based biosensor, surface-enhanced Raman scattering, microfluidic chip, and molecular imprinting technologies were especially emphasized. Moreover, this study provides a view of current accomplishments, challenges, and future development directions of nanotechnology in aquatic product safety evaluation.

Should ebselen be considered for the treatment of mercury intoxication? A minireview

Mercury is a ubiquitous environmental contaminant and can be found in inorganic (Hg0, Hg+ and Hg2+) and organic forms (chiefly CH3Hg+ or MeHg+). The main route of human, mammals and bird exposure occurs via predatory fish ingestion. Occupational exposure to Hg0 (and Hg2+) can also occur; furthermore, in gold mining areas the exposure to inorganic Hg can also be high. The toxicity of electrophilic forms of Hg (E+Hg) is mediated by disruption of thiol (-SH)- or selenol (-SeH)-containing proteins. The therapeutic approaches to treat methylmercury (MeHg+), Hg0 and Hg2+ are limited. Here we discuss the potential use of ebselen as a potential therapeutic agent to lower the body burden of Hg in man. Ebselen is a safe drug for humans and has been tested in clinical trials (for instance, brain ischemia, noise-induce hearing loss, diabetes complications, bipolar disorders) at doses varying from 400 to 3600 mg per day. Two clinical trials with ebselen in moderate and severe COVID are also approved. Ebselen can be metabolized to an intermediate with -SeH (selenol) functional group, which has a greater affinity to electrophilic Hg (E+Hg) forms than the available thiol-containing therapeutic agents. Accordingly, as observed in vitro and rodent models in vivo, Ebselen exhibited protective effects against MeHg+, indicating its potential as a therapeutic agent to treat MeHg+ overexposure. The combined use of ebselen with thiol-containing molecules (e.g. N-acetylcysteine and enaramide)) is also commented, because they can have synergistic protective effects against MeHg+.

Spatial distribution of potentially toxic elements contaminations and risk indices of water and sediments in the Darband and Samana streams, Pakistan

This study examined potentially toxic elements (PTE) of water and sediments in the Darband and Samana streams of Hangu District. Darband and Samana streams are the main fluvial ecosystems of Hangu District, Pakistan, directly or indirectly affecting more than 0.52 Million people. Water and sediment samples were collected and analyzed for PTE utilizing inductively coupled plasma mass spectrometry (ICP-MS). Water characteristics of Darband and Samana streams were noted within the WHO drinking water guidelines, except for Turbidity and sulfate. Most water characteristics showed higher values in the Samana stream than in the Darband stream. Similarly, most of PTE showed higher concentrations in sediments collected from the Samana stream than the Darband stream. For ecological risk evaluation, several pollution indices were employed to assess the eco-toxicological consequences. The highest contamination factor (CF) value of 15 and 20 were exhibited by molybdenum (Mo) in the Samana and Darband streams showing very high contamination. Similarly, the pollution load index (PLI) showed that 24% of the sediment samples were polluted (PLI > 1). Furthermore, a high ecological risk in a range of 160 < ERI < 320 was observed for Mo, while a low ecological risk ERI < 40 was by As for the Darband and Samana streams sediments. Statistical techniques revealed that various anthropogenic sources primarily contaminated in water and sediment. Therefore, this study recommends regular monitoring PTE contaminations in the area to avoid any health hazards in the future.

Concentration ciguatoxins in fillet of fish: A global systematic review and meta-analysis

In the current study, an attempt was made to meta-analyze and discuss the concentration of ciguatoxins (CTXs) in fillets of fish based on country and water resources subgroups. The search was conducted in Scopus and PubMed, Embase and Web of Science to retrieve papers about the concentration of CTXs in fillet fish until July 2022. Meta-analysis concentration of CTXs was conducted based on countries and water resources subgroups in the random effects model (REM). The sort of countries based on the pooled concentration of CTXs was Kiribati (3.904 μg/kg) > Vietnam (1.880 μg/kg) > Macaronesia (1.400 μg/kg) > French (1.261 μg/kg) > China (0.674 μg/kg) > Japan (0.572 μg/kg) > USA (0.463 μg/kg) > Spain (0.224 μg/kg) > UK (0.170 μg/kg) > Fiji (0.162 μg/kg) > Mexico (0.150 μg/kg) > Australia (0.138 μg/kg) > Portugal (0.011 μg/kg). CTXs concentrations in all countries are higher than the safe limits of CTX1C (0.1 μg/kg). However, based on the safe limits of CTX1P, the concentrations of CTXs in just Portugal meet the regulation level (0.01 μg/kg). The minimum and maximum concentrations of CTXs were as observed in Selvagens Islands (0.011 μg/kg) and St Barthelemy (7.875 μg/kg) respectively. CTXs concentrations in all water resources are higher than safe limits of CTX1C (0.1 μg/kg) and CTX1B (0.01 μg/kg). Therefore, it is recommended to carry out continuous control pans of CTXs concentration in fish in different countries and water sources.

The concentration of potentially toxic elements (PTEs) in Iranian rice: a dietary health risk assessment study

In the present study, six potentially toxic elements (PTEs), including chromium (Cr), arsenic (As), cadmium (Cd), lead (Pb), copper (Cu), and nickel (Ni), were determined in 41 domestic rice samples collected from Tehran using ICP-OES (inductively coupled plasma-optical emission spectrometry). The mean concentration of Cd, As, Cu, Pb, Cr, and Ni was found as 0.014 ± 0.01, 0.018 ± 0.005, 2.15 ± 1.84, 0.42 ± 0.31, 0.1 ± 0.16, and 0.48 ± 0.36 mg kg-1, respectively. Possible risks due to ingestion of PTEs via rice consumption for children and adults were assessed by Monte Carlo simulation. The 50th percentile of estimated Cr intake for children through domestic rice consumption exceeded the maximum tolerable daily intake. There was only a potential non-carcinogenic risk for single Cr exposure for children. The 95th percentile of the estimated hazard index (HI) for children and adults was 4.34 and 1.05, indicating a potential non-carcinogenic risk related to multiple PTE exposure. The lifetime cancer risk (ILCR) values derived from Cr, Ni, As, and Cd exposure exceeded the threshold value, indicating a carcinogenic risk due to PTEs' exposure. The deterministic assessment demonstrates that the Tehran population may be at risk through domestic rice consumption. This study indicates that risk related to the exposure to multiple PTEs through the consumption of rice in adults and children in Tehran is recognized as an important issue, thus supporting the importance of cumulative analysis of the risk of exposure to PTEs through food. Finally, national strategic environmental assessment and technological solutions for monitoring and protecting freshwater, soil, waste management, and chemicals as a global concern policy are needed for public health.

Recent Research on Municipal Sludge as Soil Fertilizer in China: a Review

Due to the annual increase in wastewater treatment in most Chinese cities, a major environmental issue has arisen: safe treatment, disposal, and recycling of municipal sludge. Municipal sludge has a high content of carbon and essential nutrients for plant growth; hence, it has gained interest among researchers as a soil fertilizer. This study discusses the potential usage of municipal sludge as soil fertilizer (indicators include nitrogen (N), phosphorus (P), and trace elements) along with its shortcomings and drawbacks (potentially toxic elements (PTEs), organic matter (OM), pathogens, etc.) as well as reviews the latest reports on the role of municipal sludge in land use. The use of municipal sludge as a soil fertilizer is a sustainable management practice and a single application of sludge does not harm the environment. However, repeated use of sludge may result in the accumulation of harmful chemicals and pathogens that can enter the food chain and endanger human health. Therefore, long-term field studies are needed to develop ways to eliminate these adverse effects and make municipal sludge available for agricultural use.