Mercury is ubiquitous in the global environment, ensuring universal exposure. Some forms of mercury are especially neurotoxic, including clinical signs at high doses. However, typical human exposures occur at low to moderate doses. Only limited data about neurotoxicity at low doses are available, and scientists differ in their interpretation. Dose-response data on neurodevelopment are particularly limited. Despite or perhaps because of the lack of sufficient or consistent scientific data, public concern about a link between mercury exposure and developmental disabilities has been rising. After reviewing the data, the US Environmental Protection Agency proposed a reference dose (an estimate of a daily dose that is likely to be without a risk of adverse effects over a lifetime) for methyl mercury that is substantially lower than previous guidelines from the World Health Organization, the US Agency for Toxic Substances and Disease Registry, and the US Food and Drug Administration. Some questions have been raised about the Environmental Protection Agency's guidelines, but the issue remains unresolved. Meanwhile, consumer groups have raised questions about the potential link between mercury exposure and autism spectrum disorders as well as other adverse neurodevelopmental outcomes. This hypothesis has prompted some parents to seek regulatory, legal, or medical remedies in the absence of firm evidence. This article reviews what is known about mercury neurotoxicity and neurodevelopmental risk. Our intent is to focus the debate about mercury on 1) additional research that should be sought and 2) defining the principal issues that public policy makers face.

Fish constitutes an essential source of high-quality protein and is, at the same time, the source of exposure to many hazardous contaminants, namely mercury and methyl mercury (MeHg). This study aims at assessing the risk that MeHg poses to the health of adult Qatari residents through fish consumption. Data on fish consumption were collected using a self-administered online survey composed of three sections that collected information about the fish-eating patterns of the participants. The fish species that were reported to be consumed by ≥ 3% of the respondents were sampled and analyzed for their total mercury (T-Hg) content levels. MeHg concentrations were derived from T-Hg content levels using a scenario-based approach. Disaggregated fish consumption and contamination data were combined using the deterministic approach to estimate MeHg intakes. The average, 75th, and 95th percentiles of the MeHg intake estimates were determined and compared to the tolerable weekly intake (TWI) set by the European Food Safety Agency (EFSA) (1.3 μg·kg^−1·w^−1). All fish samples contained T-Hg at levels ˂ 0.3–0.5 µg/g with a mean value of 0.077 µg/g. The study population had an average fish consumption of 736.0 g/week. The average estimated weekly intakes of MeHg exceeded TWI for some fish consumers including females of childbearing age and those following a high-protein diet. Our study highlights the need to establish regulatory guidelines and dietary advice based on risk/benefit ratio.

This study identified the levels of arsenic, cadmium, mercury, and lead in 15 species of commonly consumed fish in Thailand (7 freshwater species, 8 marine species), as well as the risk of these toxic elements for consumers. Inductively coupled plasma mass spectrometry (ICP-MS-MS) was used to identify toxic elements, while an exposure assessment was conducted by applying consumption amounts from the national food consumption survey to the toxic element contents in the fish samples. The results showed that the fish contained arsenic ranging from less than the limit of detection (LOD) to 8.51 mg/kg fresh weight (FW), cadmium ranging from the LOD to 0.04 mg/kg FW, and mercury ranging from the limit of quantitation (LOQ) to 0.38 mg/kg FW. Lead was found in small amounts (<LOQ) when compared to the Codex and Thailand’s standards. Only grouper had a higher mercury content (0.55 mg/kg FW) than that of the Codex standard, but it was lower than the notification requirement of Thailand’s Ministry of Public Health. Based on the estimated daily intake scenario, the consumption of most fish species posed a low risk of concern in terms of cadmium and lead. A high risk of concern was found for arsenic exposure, with the exception of long, non-scaly fish (catfish and dory). Marine fish, with the exception of Indo-Pacific mackerel, also posed a high risk of mercury exposure, but only in the case of a high mercury content, high consumption, or both. For a high arsenic content with high consumption or both, children aged 0–5.9 years were at a high risk of concern. Food safety authorities should regularly monitor the levels of toxic element contamination in high-risk food products.

Abstract Marine pollution caused by heavy metals has emerged as a significant environmental concern, garnering increased attention in recent years. The accumulation of heavy metals in the tissues of marine organisms poses substantial threats to both marine ecosystems and human populations that rely on seafood as a primary food source. Fish and crustaceans are effective biomonitors for assessing heavy metal contamination in aquatic environments. In this study, we determined the concentrations of several heavy metals, including cadmium (Cd), lead (Pb), nickel (Ni), mercury (Hg), and tin (Sn), in four fish species (Mugil cephalus, Mugil capito, L. aurata, and Morone labrax) and five crustacean species (S. rivulatus, Cerastoderma glaucum, Paratapes undulatus, R. decussatus, Callinectes sapidus, and Metapenaeus Stebbingi) from Temsah Lake during both winter and summer seasons. To evaluate the potential ecological and health risks associated with consuming these fish and crustacean species, we calculated the metal pollution index (MPI), weekly intake (EWI), target hazard quotient (THQ), and carcinogenic risk (CR) values. The results revealed a noticeable increase in metal levels during the summer compared to winter in the studied samples. Moreover, the concentration of heavy metals in the muscles of the species generally exceeded those in the liver and gills. The MPI values indicated that Morone labrax exhibited the highest values during winter, while L. aurata showed the highest v decussatus, Callinectes sapidus, and Metapenaeus Stebbingi ) from Temsah Lake during both winter and summer seasons. To evaluate the potential ecological and health risks associated with consuming these fish and crustacean species, we calculated the metal pollution index (MPI), weekly intake (EWI), target hazard quotient (THQ), and carcinogenic risk (CR) values. The results revealed a noticeable increase in metal levels during the summer compared to winter in the studied samples. Moreover, the concentration of heavy metals in the muscles of the species generally exceeded those in the liver and gills. However, consuming contaminated seafood can pose significant health risks to humans, particularly in terms of exposure to heavy metals such as mercury, lead, and cadmium 15 , 16 . The health effects of heavy metal exposure can range from neurological damage and developmental disorders to cancer and cardiovascular disease 17 – 19 . The World Health Organization (WHO) has established guidelines for safe levels of heavy metals in seafood products, but many studies have found that a significant proportion of seafood consumed worldwide exceeds these limits WHO 20 . Connelly et al. 21 found that more than half of the seafood samples tested in the United States exceeded the safe limit for mercury. To address these gaps in knowledge, further research is needed to provide valuable insights into the levels of metal contamination in a wider range of fish and crustacean species from Temsah Lake and to investigate the distribution of metals in different organs of these aquatic species. In addition, comprehensive risk assessments should be conducted to determine the potential health risks associated with consuming contaminated seafood from Temsah Lake. By identifying the metal contamination levels in seafood, researchers can inform policy decisions and management strategies to mitigate the risks associated with metal pollution in aquatic ecosystems. Health risk assessment Estimated weekly intake (EWI) The estimated weekly intake (EWI) of heavy metals depends on various factors, such as the concentration of the metal, food consumption, and body weight. To assess the potential risk of consuming fish with high heavy metal content, a number of assumptions were made in this study. Firstly, it was assumed that the amount of ingested dose was equivalent to the absorbed pollutant dose, according to USEPA 42 guidelines. Secondly, the effect of cooking on the pollutants was disregarded, as per the findings of Chien et al. 43 . Thus, the EWI of heavy metals was calculated using the following formula. Human health risk assessment To assess potential health risks associated with the consumption of fish and crustacean species, the estimation values of weekly intake (EWI), target hazard quotient (THQ), hazard index (HI), and carcinogenic risk (CR) were calculated. Studies calculate these values based on a consumption frequency of seven times a week to evaluate health risks related to fish consumption. However, it can be assumed that due to the high price of fish, it is not commonly consumed at such a high frequency in Egypt. Therefore, health risk indices were calculated based on the assumption of consuming fish and crustacean species once a week. aurata exhibited the highest EWI values, whereas Paratapes undulatus showed the highest EWI values among the studied crustacean samples. These findings indicate potential health risks associated with the weekly intake of Paratapes undulatus. Assessing human health risks associated with consuming contaminated fish often involves the calculation of established or recommended indices, such as the target hazard quotient (THQ) and hazard index (HI). To further evaluate the safety of fish consumption, the THQ was utilized as a meaningful assessment index for potential health hazards to consumers 69 . Based on these findings, it can be concluded with confidence that consuming the studied fish and crustacean species from Temsah Lake does not pose any significant health hazards to consumers. However, it is recommended to continue ongoing monitoring and research efforts to ensure the sustained safety and sustainability of seafood consumption in the region. Supplementary Information Supplementary Tables. Author contributions Authors A and D wrote the main manuscript text. Author B collected the samples and prepared the figures. Author C conducted the analysis. All authors reviewed the manuscript.

Consumption of freshwater fish contaminated with heavy metals is a major pathway for chronic human exposure, particularly in riverine communities where fish constitute a primary source of dietary protein source. This study assessed the concentrations of Mn, Fe, Cu, Zn, Ni, As, Cd, Pb, and Cr in muscle tissues of four trophically diverse species: Alestes nurse, Distichodus affinis, Malapterurus electricus, and Hyperopisus bebe from the Dukku River, and evaluated carcinogenic and non-carcinogenic health risks for adults and children’s consumers. Across multiple fishing hotspots, a total of 284 specimens were purposely collected and analyzed by atomic absorption spectrophotometer. Ecotoxicological contamination was evaluated using the Metal Pollution Index (MPI), and health risks were characterized through Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), Hazard Index (HI), and Cancer (Risk). Mean concentrations of Cd, Fe, Cu, As, Mn, and Cr differed significantly (p < 0.05) across species, with M. electricus recorded the highest MPI values of 2.19 × 10-6, driven by elevated arsenic. Fe and Zn dominated the EDI across species, with children consistently exhibited higher exposure than adults. The THQ for As in M. electricus is > 1 for children, while HI > 1 for children consuming M. electricus, D. affinis and H. bebe, indicating potential non-carcinogenic health risks. As and Cd were the dominant contributors to carcinogenic risk for children consuming these three speci

The ecological risks and health hazards of heavy metals pollution in Taihu Lake have received widespread concern. This study has developed a species-pollution dataset which includes a large amount of data on heavy metal pollution in Taihu fish. The heavy metal contamination poses a significant threat to human consumption, but no studies have been conducted to assess the risk of exposure to consumption of these fish and to make recommendations for their consumption. In this study, we systematically integrated the relevant data in the dataset, analyzed its contamination level using PI (single pollution index) and MPI (metal pollution index) models, and assessed health hazards of fish consumption using THQ (target hazard quotient) and ILCR (incremental lifetime cancer risk) models. Results showed that the contamination levels of heavy metals in fish varied in a feeding habit and living habit dependent manner. The risk of non-cancer health is the highest from consuming omnivorous fish, then from carnivorous and herbivorous fish. The ILCR model predicted that the long-term Taihu consumption of omnivorous fish may pose a potential carcinogenic risk, especially for children. In all, our study provided a comprehensive understanding on the risk of heavy metals in Taihu. Accordingly, it is recommended that children should try to choose herbivorous fish when consuming fish from Taihu Lake while avoiding long-term consumption of omnivorous fish.

The presence of mercury in fish is a health concern for people who eat them, especially for women who are or may become pregnant, nursing mothers, and The presence of mercury in fish is a health concern for people who eat them, especially for women who are or may become pregnant, nursing mothers, and young children. Fish and shellfish concentrate mercury in their bodies, often in the form of methylmercury, a highly toxic organomercury compound. This element is known to bioaccumulate in humans, so bioaccumulation in seafood carries over into huma The presence of mercury in fish is a health concern for people who eat them, especially for women who are or may become pregnant, nursing mothers, and young children. Fish and shellfish concentrate mercury in their bodies, often in the form of methylmercury, a highly toxic organomercury compound. This element is known to bioaccumulate in humans, so bioaccumulation in seafood carries over into human populations, where it can result in mercury poisoning. Mercury is dangerous to both natural ecosystems and humans because it is a metal known to be highly toxic, especially due to its neurotoxic ability to damage the central nervous system. In human-controlled ecosystems of fish, usually done for market production of wanted seafood species, mercury clearly rises through the food chain via fish consuming small plankton, as well as through non-food sources such as underwater sediment. Fish products have been shown to contain varying amounts of heavy metals, particularly mercury and fat-soluble pollutants from water pollution. Species of fish that are long-lived and high on the food chain, such as marlin, tuna, shark, swordfish, king mackerel and tilefish contain higher concentrations of mercury than others. Cetaceans (whales and dolphins) also bioaccumulate mercury and other pollutants, so populations that eat whale meat, such as the Japanese, Icelanders, Norwegians and the Faroese, are also vulnerable to mercury ingestion. Regulation of these potential sources of pollution reduces the amount of mercury that ends up in fish and, through biomagnification, in humans. In addition to enacting legislation controlling the mercury levels in potential pollutants, Japan has directly influenced the environment by issuing regulations setting acceptable levels of environmental mercury pollution. It is Japan's goal to promote international mercury legislation in hopes of preventing any country from experiencing what it did. Despite Japan's extensive regulation and experience with mercury-based disasters, there is still little information provided to the public. The Japanese Federal Fish Advisory's recommendations are less strict than those in America.