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Oyster fishing in Mexico holds significant importance, but official records show a consistent drop in production. To understand the reproductive behaviour of key oyster species —Crassostrea corteziensis, Saccostrea palmula, and Striostrea prismatica— in a southeastern Gulf of California lagoon (May 2019 to April 2020), this research delved into their reproductive traits. C. corteziensis and S. palmula exhibited five phases of gonadal development, including: undifferentiated/resting, initial gametogenesis, advanced gametogenesis, maturation, and spawning; S. prismatica showed four: undifferentiated/resting, gametogenesis, maturation, and spawning phases. The three oysters displayed hermaphroditism. Spawning peaks varied: C. corteziensis from September to November, S. palmula from May to September, and S. prismatica from August to November. Sex ratio (female:male) of S. prismatica differed from the expected 1:1 proportion. C. corteziensis and S. palmula showed continuous reproduction; S. prismatica displayed a single annual reproductive cycle. Since the obtained peak spawning of C. corteziensis and S. prismatica presented discrepancy with the official protection period and there are no regulatory measures for S. palmula, the information on their reproductive behaviour aids in regulating their extraction for sustainability and conservation in the southeastern Gulf of California. Similar information can be replicated in coastal areas of other latitudes where several oyster species coexist. [ABSTRACT FROM AUTHOR]

Opuntia is a well-known plant for its folkloric use and nutritional composition. This work aimed to evaluate the physicochemical characteristics, as well as the mineral composition realized by inductively coupled plasma-mass spectrometry (ICP-MS) for cultivated and wild Algerian Opuntia species. The results showed a significant difference in length, diameter, and weight between both Opuntia fruits. The highest pH, brix°, and total sugar content were found in the pulp of cultivated fruit compared to the wild one. Moisture was found to be higher in pulp of both species with more than 90% compared to their seeds (33%); however, ashes content was more determined in seeds with 1.04%. Moreover, high protein content was found in wild Opuntia parts (more than 200 mg bovine serum albumin equivalent/100 g dry matter), which also presented higher ascorbic acid and betalain contents, particularly in the pulp with 211.45 mg EAA/100 g DM and 312.91 mg/100 g DM, respectively, compared to the cultivated Opuntia. Finally, the mineral profile revealed a significant countenance of all species' fractions in many important minerals for human organism functioning, like iron, magnesium, zinc, and potassium. [ABSTRACT FROM AUTHOR]

Information of essential elements in sharks are still limited, especially from Indonesian waters. The aims of this study were to report the concentration of 12 elements (Mg, Ca, V, Cr, Mn, Fe, Co, Cu, Zn, Se, Sr, and Mo) using inductively coupled plasma–mass spectrometry (ICP-MS) in Sphyrna lewini (hammerhead shark) and Rhizoprionodon acutus (milk shark) from West Java waters, Indonesia. The results of this study showed that the concentration of Mg, Ca, Fe, Mn, Zn, Cu, and Sr in S. lewini are higher than in R. acutus. The chemometrics analysis using partial least squares-discriminant analysis (PLS-DA) showed that total length (TL), total weight (TW), Co, Se, V, and Cu concentration were important variables in sample classification to determine milk shark and hammerhead shark. Overall essential elements in sharks showed positive correlation to morphometric and metal–metal correlation. [ABSTRACT FROM AUTHOR]

Elemental ratios (δ13C, δ15N and C/N) and carbon and nitrogen concentrations in macrophytes, sediments and sponges of the hypersaline Al-Kharrar Lagoon (KL), central eastern Red Sea coast, were measured to distinguish their sources, pathways and see how they have been influenced by biogeochemical processes and terrestrial inputs. The mangroves and halophytes showed the most depleted δ13C values of –27.07±0.2 ‰ and –28.34±0.4 ‰, respectively, indicating their preferential 12C uptake, similar to C3-photosynthetic plants, except for the halophytes Atriplex sp. and Suaeda vermiculata which showed δ13C of –14.31±0.6 ‰, similar to C4-plants. Macroalgae were divided into A and B groups based on their δ13C values. The δ13C of macroalgae A averaged –15.41±0.4 ‰, whereas macroalgae B and seagrasses showed values of –7.41±0.8 ‰ and –7.98 ‰, suggesting uptake of HCO3– as a source for CO2 during photosynthesis. The δ13C of sponges was –10.7±0.3 ‰, suggesting that macroalgae and seagrasses are their main favoured diets. Substrates of all these taxa showed δ13C of –15.52±0.8 ‰, suggesting the KL is at present a macroalgae-dominated lagoon. The δ15N in taxa/sediments averaged 1.68 ‰, suggesting that atmospheric N2-fixation is the main source of nitrogen in/around the lagoon. The heaviest δ15N (10.58 ‰) in halophytes growing in algal mats and sabkha is possibly due to denitrification and ammonia evaporation. The macrophytes in the KL showed high C %, N %, and C/N ratios, but this is not indicated in their substrates due possibly to a rapid turnover of dense, hypersaline waters carrying most of the detached organic materials out into the Red Sea. The δ13C allowed separation of subaerial from aquatic macrophytes, a proxy that could be used when interpreting paleo-sea level or paleoclimatic changes from the coastal marine sediments. [ABSTRACT FROM AUTHOR]

In recent years, the Vietnamese government has dedicated considerable planning and resources toward agricultural restructuring. These far-reaching efforts include promotion of intensive shrimp farming in the Mekong Delta to encourage the sustainable development of rural livelihoods. However, while intensive shrimp production may improve economic wellbeing, the current production practices raise concerns about the impacts on the local environment. The current study examines the economic and environmental efficiencies associated with the two primary species of farmed shrimp in four coastal provinces of the Mekong Delta. The study employs the material balance principle as a framework which considers the inputs to production and the outputs which may be undesirable. Using the efficiency estimates, we measure and investigate the trade-offs between the economic and environmental efficiencies for the shrimp farming in the Vietnamese Mekong Delta. The results suggest that the shrimp farming produces a significant nutrient surplus for either species. The analysis also suggests that achieving cost efficiency and environmental efficiency would help the shrimp farmers to reduce the undesirable outputs and that the movement from the cost efficiency to the environmental efficiency could result in a reduction of both production costs and nutrients. Based on these results, we offer policy recommendations for economically feasible and environmentally friendly shrimp farming. The material balance approach provides a useful lens through which to investigate agricultural production. [ABSTRACT FROM AUTHOR]

While the role that groundwater discharge plays in supporting primary production in coastal ecosystems is well recognized, there is still limited evidence on its impacts higher up the food chain. In this study, we investigate the role of groundwater discharge in supplying nitrogen and carbon to the Mediterranean mussels (Mytilus galloprovincialis) in the Salses-Leucate lagoon (France). Nitrogen (δ15N) and carbon (δ13C) isotope values in the mantle and gill tissues of Mediterranean mussels are used to trace nitrogen and carbon sources at groundwater-exposed sites and a control site. Our results show similar isotope values for mantle and gill tissues, likely due to relatively stable environmental conditions in the study sites and to the biochemical composition of tissues. Diet shift, fractionation, and the physiological function of tissues could also explain this observation. δ15N values in mussel tissues increase overall in winter at both the groundwater-influenced sites (4.9 to 7.8‰) and the control site (3.4 to 8.5‰) in comparison with those in autumn (3.5 to 7.4‰ at the groundwater-influenced sites and 4.5 to 6.9‰ at the control site), likely due to reduced food supply and slower metabolism in winter, resulting in 15N enrichment. In contrast, mussel δ13C values decrease in winter at the groundwater-influenced sites (− 23.4 to − 21.6‰) and the control site (− 22.0 to − 19.0‰), suggesting input from 13C-depleted sources originating from groundwater input. The comparison of the isotopic values of mussel tissues and potential food sources indicates that the main diet of M. galloprovincialis in the Salses-Leucate lagoon is a mixture of groundwater particulate organic matter (POM), lagoon POM, and marine POM (POM as a proxy of phytoplankton). Depleted δ13C values in mussel tissues, particularly at groundwater-exposed sites, provide evidence of uptake of groundwater-derived nutrients. The ecological benefit of groundwater input on filter feeders results from local increases in food availability (mainly phytoplankton), supported by groundwater-derived nitrogen and carbon. In summary, this study shows the combined (a) indirect effect of groundwater discharge on mussel growth via uptake of their food, phytoplankton, and (b) the likely direct feeding of groundwater POM by M. galloprovincialis. It thus shows the important ecological implication of groundwater inputs in coastal lagoon food webs. [ABSTRACT FROM AUTHOR]

During January 2013, a mining spill occurred in the Santa Maria mining region, releasing around 300,000 m3 of tailings on Los Remedios river, which was transported through the San Lorenzo river and finally to El Comedero (EC) dam. Twenty months later, we examined the concentrations of Hg and Se in the muscle, liver, gills, and guts of three fish species (Cyprinus carpio, Oreochromis aureus, Micropterus salmoides) captured in the EC dam to assess the performance of the cleaning operations. A high Se concentration in the liver of all species (carp, 1.2 ± 0.4; tilapia, 3.9 ± 2.1; bass, 3.5 ± 1.1 µg g−1 ww) was consistently observed, while this behavior was only found in the blue tilapia for Hg (0.15 ± 0.11 µg g−1 ww). Tilapia (benthic-detritivorous) exhibited the highest Se concentrations compared to the carp (omnivore) and the largemouth bass (piscivore). In contrast, the largemouth bass had the highest Hg levels in the muscle compared with the other fishes. Such differences could be related to the different metabolism and feeding habits among species. Compared to a tilapia study carried out three months after the mine spill during a mortality event, a decrease was evident in the liver for Se and Hg by 7.2 and 4.7 times, respectively. This reveals that cleaning operations were more efficient for Se and less for Hg, and that a prolonged period was required for the partial recovery of the element levels in fish from sites impacted by mining. Considering the Mexican consumption scenarios for each fish species, it could be concluded that there will be no non-cancer risk by exposure to Hg or Se. [ABSTRACT FROM AUTHOR]

An increasing number of organic and inorganic pollutants are being detected in the marine environment, posing a severe threat to the ecosystem and human health, even in trace concentrations. Isotope ratio mass spectrometry (IRMS) is one of the critical methods for determining the origin and fate of environmental pollutants and characterising their transformation processes. It has been used for a relatively long time for ecological monitoring of some well-studied industrial hydrocarbons at contaminated sites. However, the method still faces many analytical challenges. This review provides a comprehensive overview of recent technical advances concerning IRMS analysis of various contaminants and discusses typical pitfalls encountered in marine environment analysis. Particular attention is given to the study of sampling techniques and sample preparation for examination, often the keys to successful research given the complexity of marine matrices and the diverse and numerous nature of contaminants. Prospects for developing IRMS to monitor pollution sources and pollutant transformation in the marine environment are outlined. [ABSTRACT FROM AUTHOR]

Lead (Pb) is ubiquitous in urban environments, and it is a risk factor for wildlife. But wildlife are particularly at risk for exposure near smelters in urban areas where higher than safe Pb levels in the soil have the potential to transfer to the food chain. Therefore, we investigated whether wildlife are at risk of Pb exposure and differences in Pb bioaccumulation in trophic levels at a Superfund site in an urban area of Colorado. We sampled soil, vegetation, arthropods, and birds at four sites: two contaminated sites (one at the Superfund site and one near the Superfund site) and two reference sites with low predicted Pb contamination. We found significantly higher Pb levels in the soil at the contaminated Slag pile at the Superfund site, compared to the other sites. At the Slag pile, Pb levels were the highest in vegetation and both arthropods and birds accumulated Pb. However, Pb did not increase between trophic levels in the terrestrial food web at the site. We concluded that smelter operations at the Superfund site resulted in significantly higher levels of Pb in the soil and sublethal accumulation in all taxa studied. This research can be used to mitigate the risks to vulnerable wildlife populations exposed to Pb at the Superfund site. Further examination of Pb toxicity in vulnerable taxa is critical to conserving wild populations and ecosystems near contamination zones. [ABSTRACT FROM AUTHOR]

Coastal lagoons are vulnerable to eutrophication processes. In this study, we evaluate the eutrophication process in the restricted, arid subtropical Tóbari coastal lagoon, located in the eastern coast of the Gulf of California, where the main source of nutrient inputs and other pollutants is agricultural wastewater from the Yaqui Valley. The Assessment of Estuarine Trophic Status (ASSETS) model and the Trophic State Index (TRIX) were used to evaluate eutrophication. Overall, ASSETS showed that the Tóbari lagoon has a moderate eutrophication process, with seasonal symptoms of hypoxia, increased phytoplankton biomass, dominance of macroalgae (indicative of nutrient enrichment), and blooms development of potentially harmful algae species. The TRIX showed that the lagoon is mesotrophic most of the year. Challenges of environmental management detected correspond to reducing the input of nutrients and others contaminants from anthropic sources: agriculture, shrimp farming, livestock, and urban zones. [ABSTRACT FROM AUTHOR]

Total mercury (Hg) and selenium (Se) contents were determined in oysters Saccostrea palmula and Crassostrea corteziensis soft tissues from four coastal lagoons of the southeastern Gulf of California. The annual Hg mean concentrations for S. palmula (0.09 ± 0.04 µg g− 1, wet weight) and C. corteziensis (0.08 ± 0.04 µg g− 1) were similar (p ˃ 0.05) among the lagoons and did not exceed the limit established by the Norma Oficial Mexicana and World Health Organization (< 1.0 µg g− 1 Hg). On the other hand, the annual mean concentrations of Se for S. palmula (3.34 ± 0.96 µg g− 1) and C. corteziensis (2.79 ± 0.89 µg g− 1) were higher (p < 0.05) in El Colorado lagoon. The Se/Hg molar ratios were above 1; the positive selenium health benefit value index suggested that Se load in oysters could reduce the Hg potential toxic effect. The hazard quotient for Hg in both species was below 1. Therefore, the consumption of oysters does not represent a risk due to Hg ingestion. [ABSTRACT FROM AUTHOR]

Heavy metal contamination in surface water is widespread throughout the world as a result of numerous anthropogenic activities and geo-genic mechanisms. This contamination is also affecting aquatic life, as fish have the potential to acquire heavy metals in their tissues making them vulnerable. Worldwide lakes are an important source of water for the inhabitants of the area. So, in the present study, we have focused on the Satpara Lake to check the extent of heavy metal pollution and their accumulation in fish to provide baseline data for metal pollution management. Samples were collected from three locations (inflow, center, and outflow sites) during two seasons (summer and winter). Inductively coupled plasma optical emission spectrometry (ICP-OES) was applied to analyze heavy metals concentration. Among the metals, Cd, Pb, As, and Fe revealed relatively higher concentrations. The highest concentration of heavy metal found in water and fish was of Cd, i.e., 8.87 mg L−1 and 18.19 mg L−1 in summer season, respectively. Arsenic concentration was also higher than the permissible limits in both water (0.76) and fish (1.17 mg L−1). The water quality assessment showed that in the summer season, the HPI (heavy metal pollution index) value 253.01 was more than 100, indicating the bad quality of water for drinking purposes. However, the HPI value 35.72 was less than 100 in winter. Toxicity hazard calculation of fish in summer seasons gives Hi values greater than 10.0, indicating the acute effect on human health as compared to winter. [ABSTRACT FROM AUTHOR]

The failure of a tailings dam occurred in January 2013 at the Santa María de Otáez mining region (Mexico) released a spill (~ 300,000 m3) on Los Remedios River, which was transported through the San Lorenzo River, and finally to El Comedero (EC) dam. The concentrations of metal(loid)s in the muscle, liver, gills, and guts of three fish species (Cyprinus carpio, Oreochromis aureus, Micropterus salmoides) collected from EC dam were examined twenty months later to assess the performance of the cleaning operations. The bioaccumulation patterns of the metal(loid)s in the tissues were different in the three fish species. Tilapia had the highest Cd (11.23 ± 8.53 µg g−1) and Cu (871 ± 1261 µg g−1) concentrations in the liver, as well as As concentration (83.6 ± 61.7 µg g−1) in the gut, while the highest Zn concentration (745 ± 356 µg g−1) was measured in the gills of the carp. Such variability can be caused by the variant bioavailability of the metal(loid)s and by the feeding habits of each species; and also by the fact that some metals are essential and better regulated by organisms than other non-essential. Compared to a study of tilapia carried out 90 days after mine spill, a decrease was evident in the liver for As, Cd, Cu, and Zn by 129, 5, 10, and 1.7 times, respectively. This revealed that cleaning operations were more efficient for As. The target hazard quotient and the hazard index were < 1, which indicates there will be no risk of consuming muscle in moderated rations of the three fish species. [ABSTRACT FROM AUTHOR]

In this study, the concentration of six metal(loid)s was examined in the fish Oreochromis aureus collected from El Comedero dam during a massive mortality event induced by a mine tailing spill. A major spill (~ 300,000 m3) of waste was released into the San Lorenzo River System following a rupture in the tailing dam of a mining plant in NW Mexico; consequently, the discharged material flowed into El Comedero dam. The accumulation of metal(oid)s in the tissues of O. aureus showed higher levels in the liver than in the guts and muscle. Concentrations in the liver were high (As, 1.1–1063; Cd, 8.9–392; Cu, 372–59,129; Hg, 0.46–19.79; Se, 8.7–748; and Zn, 116–820 μg g−1), revealing that these fish were exposed to high concentrations of these elements. The mortality of fish could have resulted from the combined effect of the six analyzed metal(loid)s, as well as other residues present in mine tailings. [ABSTRACT FROM AUTHOR]

This study aimed to establish the distribution of As, Cd, Cu, Pb, and Zn, in the muscle and liver of the spotted ratfish Hydrolagus colliei from the northern Gulf of California to establish the bioaccumulation background data in this species. The individuals (n = 110) were obtained by bycatch from the Gulf of California hake fisheries, and the metals and metalloid were measured by atomic absorption spectrometry. The element with the highest concentration in the muscle (15.19 ± 5.40 mg kg−1) and the liver (20.98 ± 10.30 mg kg−1) was As, followed by essential elements (Zn > Cu), and the lowest were the non-essential Pb (0.029 ± 0.014 and 0.048 ± 0.038 mg kg−1, muscle and liver, respectively) and Cd (0.022 ± 0.014 and 0.796 ± 0.495 mg kg−1, muscle and liver, respectively). The liver showed higher bioaccumulation than the muscle in all the studied elements. The sex was not a factor that influenced the bioaccumulation. The concentrations of As in the muscle did not exceed the maximum permissible limits of Mexican legislation, and < 50% of the samples exceed Cd and Pb limits of the Mexican, European Union, and WHO/FAO regulations. The differences found between the elements and tissues could be related to the different diets of the species, their migratory patterns, and their life conditions. Studies in the deep-sea water H. colliei are limited, and further investigations are needed regarding the feeding habits of H. colliei as well as the interactions of potentially toxic elements within the deep-sea water habitat. [ABSTRACT FROM AUTHOR]

The coastal lagoons of the Gulf of California support important traditional fisheries and mollusc cultures (generally oysters) and receive important volumes of agricultural, industrial and urban effluents, consumption of the oysters could pose risk to human health. The concentrations of arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), and zinc (Zn) in the oysters Saccostrea palmula and Crassostrea corteziensis, from four coastal lagoons (Altata, AL; Macapule, ML; Navachiste, NL; El Colorado, ECL) in the Southeast Gulf of California, were seasonally evaluated (summer 2019–spring 2020). The order of magnitude of potentially toxic elements concentrations in the soft tissue in both oyster species and at all sites was Zn > Fe > Cu > As > Cd > Pb. Cadmium, Cu, Pb, and Zn exceeded the maximum permissible limits in more than one sampling site. The highest concentrations (mg kg–1, wet weight) of As (4.2 ± 1.1, spring) and Cd (3.3 ± 0.7, autumn) were registered in S. palmula et al. and NL sampling sites, respectively. Crassostrea corteziensis presented higher levels of Cu (40.5 ± 6.7, spring), Pb (2.0 ± 0.4, spring), and Zn (96.9 ± 20.4, spring) in ECL and Fe (62.2 ± 25.4, autumn) in ML. The hazard quotient (HQ) values exceeded the safe level of 1 for Cd in S. palmula and C. corteziensis in NL for children (~ 16 kg weight). In addition, in children, the hazard index (HI) values in both species of oysters ranged from 0.7 to 2.1 and 0.6 to 1.9, respectively. On the other hand, the intake of the studied elements through the consumption of oysters would not induce adverse effects to human health (men and women weighing 70 and 60 kg, respectively); HQ and HI values were < 1. [ABSTRACT FROM AUTHOR]

Although various studies have reported the bioaccumulation of metals in bivalves of commercial interest from the Gulf of California (GC), the risk associated with their consumption remains poorly understood. In this study, our own and bibliographic concentrations of 14 elements in 16 species of bivalves from 23 locations were used to investigate (1) the species-specific and regional accumulation of metals and arsenic in bivalves, (2) the human health risks by age and sex, and (3) the maximum allowable consumption rates (CRlim). The assessments were done according to the US Environmental Protection Agency guidelines. The results indicate that the bioaccumulation of elements varies markedly between groups (oysters > mussels > clams) and localities (higher on Sinaloa due to intense anthropogenic activities). However, consuming bivalves from the GC remains safe for human health. To prevent health effects for residents or consumers on the GC, we recommend (1) following the CRlim proposed herein; (2) monitoring levels of Cd, Pb, and As (inorganic) in bivalves, as the elements of top concern, mainly when are consumed by children; (3) calculating CRlim for more species and locations, including at least: As, Al, Cd, Cu, Fe, Mn, Pb, and Zn; and (4) determine the regional consumption rates of bivalves. [ABSTRACT FROM AUTHOR]

BACKGROUND: Nejayote is an alkaline agro-industrial residue that is generated from the nixtamalization process of maize, whose chemical composition is made up of carbohydrates, fiber, and lipids that come mainly from the pericarp of the maize from which it comes. Furthermore, the presence of phenolic compounds has been detected when Nejayote comes particularly from pigmented maize. As an agro-industrial residue, Nejayote can be used as substrate for the growth of microorganisms, like fungi. METHODS: Three culture media were formulated using Potato Dextrose Agar (PDA) combined with filtered Nejayote extracts from 3 types of maize (withe -NWM-, red -NRM-, and purple -NPM-) and the growth capacities of Fusarium solani, Colletotrichum orbiculare, Alternaria alternata, Botrytis cinerea, and Phytophthora capsici were measured. Also, the fungi were evaluated by macroscopic parameters like mycelial growth rate and colony morphology for 7 days. RESULTS: Growth increased in all fungi strains, however, A. alternata, B. cinerea, and P. capsici showed changes in the morphology and color of the colonies, which suggests the production of secondary metabolites like pigments due to the utilization of components of Nejayote extracts as growth substrate. CONCLUSION: Filtered Nejayote extracts in combination with traditional synthetic culture media, improved a growth of fungi strains. In addition, the inherent composition of Nejayote wastewater allows it utilization to promote the synthesis of secondary metabolites from fungi cultures with potential biotechnological applications [ABSTRACT FROM AUTHOR]

Aquatic ecosystems have been suffering deleterious effects due to the development of different economic activities. Metal(loid)s are one of the most persistent chemicals in environmental reservoirs, and may produce adverse effects on different organisms. Since fishes have been largely used in studies of metal(loid)s exposure, tilapia and largemouth bass were collected in three ecosystems from the Yaqui River Basin to measure the concentrations of metal(loid)s (chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), zinc (Zn) arsenic (As), mercury (Hg), and selenium (Se)) and some biomarkers (somatic indices, metallothionein expression and histopathological analysis) in tissues of both species. Metal(loid) concentrations varied seasonally among ecosystems in tissues of both species. The elements varied seasonally and spatially in tissues of both species, with a general distribution of liver > gills > gonads. Also, biomarkers showed variations indicative that the fish species were exposed to different environmental stressor conditions. The highest values of some biomarkers were in largemouth bass, possibly due to differences in their biological characteristics, mainly feeding habits. The multivariate analysis showed positive associations between metal(loid)s and biomarkers, which are usually associated to the use of these elements in metabolic and/or regulatory physiological processes. Both fish species presented histological damage at different levels, from SI types (changes that are reversible for organ structure) to SII types (changes that are more severe but may be repairable). Taken together, the results from this study suggest that the Yaqui River Basin is moderately impacted by metals and metalloids. [ABSTRACT FROM AUTHOR]

Context: Bivalve fishery represents an important socio-economic resource in Río Negro province, and Mytilus platensis is the main exploited species. Thus, biomonitoring trace metals in this mussel is particularly relevant for both environmental protection and human consumption. Aim: Anthropogenic pollution and its environmental impact on mussels were experimentally evaluated in situ in two coastline sites of northern Patagonia. Methods: Trace metal concentrations were quantified in the water of a harbour area (Port of San Antonio Este) and a reference site (Isla Mejillón), an extraction location of M. platensis , were quantified. Metal accumulation and its effects on metabolic parameters were also measured in mussels. Results: Higher concentrations of chromium, nickel and zinc in water were registered in the harbour, along with copper and chromium in gills, digestive gland and mantle of M. platensis , were registered in the harbour. Furthermore, superoxide dismutase activity was augmented, whereas glutathione concentration was reduced in the digestive gland and mantle of mussels from that area. Moreover, the highest glutathione-S-transferase activities in mantle and lipid peroxidation, regardless of organ, were also found there. Conclusion: The harbour area has a negative effect on M. platensis and its effects on metal accumulation and oxidative imbalance are organ-specific. Implication: This work provided new insights into metal uptake of a commercialised mussel in a realistic environment in Río Negro province. Mussels are a healthy source of food, and beneficial for human consumption. Mytilus platensis fishery is an important socio-economic resource in Argentina. This species is also used worldwide as a bioindicator. Increase in bioaccumulation of metals in mussels from an area near harbour produced significant damage on its metabolism. Our results provided useful information on environmental concentrations of trace metals in the northern Patagonia coastline, as well as highlighting a possible human health risk owing to consumption of this commercialised species. [ABSTRACT FROM AUTHOR]

Environmental media discourse analysis allows researchers to explore thematic patterns in media coverage of environmental issues through qualitative observations and quantitative coding. In this paper, we review newspaper media coverage in Florida pertaining to the connections between agriculture, other non-point pollution sources, and downstream ecosystem health. We analyzed 930 articles from 2007 through 2019 to determine common patterns in how these issues are covered by Florida media, including patterns in the causes of environmental problems, potential solutions, and stakeholders mentioned. Findings suggest that water quality problems are often framed as unpredictable or episodic rather than chronic, and as requiring (and only potentially being remediated by) state-level centralized technological or infrastructural solutions. Stakeholder relationships are framed as adversarial, with environmentalists and the agricultural sector as opponents. This case study highlights key power dynamics, barriers, and opportunities for better managing and communicating about agricultural land use practices and associated downstream environmental impacts. [ABSTRACT FROM AUTHOR]

Seasonal changes of trace elements, nutrients, dissolved organic matter (DOM), and carbonate system parameters were evaluated over the largest deteriorating oyster reef in the Western Mississippi Sound using data collected during spring, summer, and winter of 2018, and summer of 2019. Higher concentrations of Pb (224%), Cu (211%), Zn (2400%), and Ca (240%) were observed during winter of 2018 compared to summer 2019. Phosphate and ammonia concentrations were higher (> 800%) during both summers of 2018 and 2019 than winter of 2018. Among the three distinct DOM components identified, two terrestrial humic-like components were more abundant during both spring (12% and 36%) and summer (11% and 33%) of 2018 than winter of 2018, implying a relatively lesser supply of humic-like components from terrestrial sources during winter. On the other hand, the protein-like component was more abundant during summer of 2019 compared to rest of the study period, suggesting a higher rate of autochthonous production during summer 2019. In addition, to their significant depth-wise variation, ocean acidification parameters including pH, pCO2, CO32−, and carbonate saturation states were all higher during both summers of 2018 and 2019. The measured variables such as trace elements, organic carbon, suspended particulates, and acidification parameters exhibited conservative mixing behavior against salinity. These observations have strong implications for the health of the oyster reefs, which provides ecologically important habitats and supports the economy of the Gulf Coast. [ABSTRACT FROM AUTHOR]

Environmental context: Intensive aquaculture is the main source of fisheries products. Thus, investigating the food safety of these products and the environmental impacts of the farms on mangroves is necessary. A shrimp productive cycle was evaluated with a focus on trace element accumulation in shrimps and effluent. The results revealed secure levels of elements in the final product; however, the effluent produced in farms is an important source of contamination to mangrove environment. Rationale: Aquaculture systems have increased in the last years due to the high demand for seafood consumption, this could impact the environment and subject fisheries to accumulation of toxic elements. To understand some parameters of food safety and environmental impact, the present study evaluated the concentration of trace elements (Al, As, Cd, Co, Cr, Cu, Mn, Mo, Pb, Se, V and Zn) throughout the production cycle of shrimp. Methodology: About 50 shrimps per cycle were collected in a shrimp farm in Brazil and their trace element contents were determined by inductively coupled plasma–tandem mass spectrometry (ICP-MS/MS) and microwave-induced plasma–optical emission spectroscopy (MIP-OES). Results: At their final lifecycle stage, shrimp samples present a content (mg g−1) of elements following the trend: Cu (102 ± 12) > Al (20.06 ± 4.24) > Zn (14.82 ± 2.46) > Mn (6.24 ± 0.94) > As (2.65 ± 0.42) > Se (0.932 ± 0.140) > Co (0.380 ± 0.05) > Mo (0.254 ± 0.03) > V (0.204 ± 0.02). Discussion: The content of Cd and Pb are in allowance with Brazil and USA legislation for crustaceans, however, the content of As is 3–4-fold higher than that allowed by guidelines in all stages of the growth of the shrimp. The final effluent of the shrimp's pond into the mangroves shows a high mass fraction of Zn and Mn that could be a source of contamination. Some correlations between some elements in the shrimp samples were found, such as As–Se, Se–Co and Se–V. This study was a scoping experiment to study the content of trace elements throughout the farming cycle of shrimps, encouraging the researcher to undergo a wide survey to evaluate the environmental impact of aquaculture shrimp farming. Environmental context. Intensive aquaculture is the main source of fisheries products. Thus, investigating the food safety of these products and the environmental impacts of the farms on mangroves is necessary. A shrimp productive cycle was evaluated with a focus on trace element accumulation in shrimps and effluent. The results revealed secure levels of elements in the final product; however, the effluent produced in farms is an important source of contamination to mangrove environment. [ABSTRACT FROM AUTHOR]

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This study aimed to develop wheat gluten hydrolysates (WGH) prepared by sequential enzymatic hydrolysis for its application in commercial beverage. The hydrolysis of WGH was performed with different combinations of commercial endo-proteases (Alcalase, A; Neutrase, N; and Protamex, P) and Flavourzyme (F) under limited hydrolysis conditions. The WGH sequentially hydrolyzed with A and other endo-proteases possessed a higher proportion of < 1 kDa fraction than those hydrolyzed with the other combinations. Hydrolysis with the A–P–F sequence produced the WGH with lower turbidity, better thermal stability, and higher L* value than the other sequences. The WGH sequentially hydrolyzed by the combination of A, P, and F showed better antioxidant activities than the others regardless of in vitro simulated gastro-intestinal digestion. In sensory evaluation, the more WGH in the beverage, the more bitter flavor and the less consumer preference; however, the formulation of peptide beverage containing 3% WGH, 0.0315% sucralose, and 1.2% maltodextrin were evaluated to be suitable for masking bitterness and increasing the preference. These results suggest that WGH sequentially hydrolyzed with A–P–F could potentially be a bioactive peptide ingredient in the beverage industry. [ABSTRACT FROM AUTHOR]

During gestation, essential and non-essential trace elements are transferred from the pregnant females to embryos. This study aimed to determine and compare the concentrations of seven essential trace elements (Fe, Zn, Se, Cu, Mn, Cr, Co) and six non-essential trace elements (As, Cd, V, U, Tl, Ag) in the muscle and the liver of a Munk's pygmy devil ray pregnant female, Mobula munkiana, and its embryo. Transfer evidence of essential and non-essential trace elements was detected in M. munkiana tissues. Arsenic was found in elevated concentrations in the pregnant female and the embryo tissues. Elevated levels of Cd, V, U, and Ag were found in the pregnant female liver, but were minimal in the embryo tissue. This is the first study to investigate maternal transfer of essential and non-essential trace elements in these species and their reproductive strategy. [ABSTRACT FROM AUTHOR]

Human consumption of the thornback guitarfish (Platyrhinoidis triseriata) is concentrated in coastal populations of the Pacific coast of Mexico as its meat is prized for its high quality. This study analyzes the distribution of mercury and selenium in the muscle and liver of Platyrhinoidis triseriata and the risk to human health associated with its consumption. In order to conduct these estimates, specimens were collected from the Eastern Pacific Ocean in 2015 and 2016 and found mean concentrations (µg g−1 wet weight) of mercury ranging from 0.02 to 0.58 in muscle and 0.10 to 0.31 in liver. Selenium ranged from 0.14 to 1.31 in muscle and from 0.93 to 4.52 in liver. Mercury levels in the muscle of P. triseriata were significantly correlated (positive correlation) with the total length of the specimens. The predominant prey of P. triseriata was the shrimp Pleuroncodes planipes and according to the biomagnification factor, only mercury was biomagnified. The risk to consumers associated with the simultaneous presence of mercury and selenium in the muscle and liver of rays under the selenium health benefit value approach indicated that consumption of P. triseriata from this area is beneficial to human health. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Marine ecosystems are subject to contamination by metals and metalloids and other elements and compounds that are emitted due to various human activities. These substances subsequently induce changes in marine biota after entering the marine environment. Marine organisms are frequently consumed worldwide because they constitute relatively cheap and accessible food items of high nutrient quality. The aim of this study was to estimate metal accumulation in frequently consumed marine species and to evaluate the associated health risks for particular population groups in a coastal region of northwestern Mexico. The marine species were consumed in different quantities between spring (from 0.29 kg year−1 for white clam, to 38.40 kg year−1 for blue crab) and autumn (from 0.34 kg year−1 for white clam, to 15.02 kg year−1 for leopard grouper). The general distribution of metal concentrations in the marine species (n = 13 in each season) evaluated in this study followed the trend of Fe > Zn > Cu > Mn > Cr with the highest metal concentrations detected during autumn. Although many metal concentrations were above the international standards of the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO), the hazard quotient (HQ) and hazard index (HI) values for the women in this study indicated that their health was not at risk due to the consumption of either fish or seafood. In contrast, the HQ and HI values determined for groups of men and children indicated that they are at risk due to the frequent consumption of most species evaluated in this study. [ABSTRACT FROM AUTHOR]

To balance the risks and benefits of fish consumption, selenium, fatty acids (DHA + EPA), and mercury in fishery products were determined. Analyzed products were canned tuna, frozen tuna (Thunnus albacares), smoked striped marlin (Tetrapturus audax), fresh Pacific sierra (Scomberomorus sierra), fresh dolphinfish (Coryphaena hippurus), fresh tilapia (Gerres cinereus), and fresh bullseye puffer (Sphoeroides annulatus). Mercury (μg g−1 wet weight) ranged from 0.01 (dolphinfish) to 0.23 (bullseye puffer); Se ranged from 0.12 to 0.25. EPA + DHA ranged from 1.16 to 10.72 mg g−1. Intake of EPA + DHA was comparable or above the recommended daily intake; Hg intake was below the reference dose but Se intake was below than recommended values for the different population groups. Considering the HBVSe, fishery products had positive values; i.e., they are healthy food items. According to the interaction of Hg and Se and the rate of fishery product consumption, the risk for consumers is below one percent. [ABSTRACT FROM AUTHOR]

Tropical lagoon ecosystems constituting lagoons with fringe mangroves are continually polluted with effluents from different sources. This study assessed the spatial variation of selected physicochemical parameters (pH, nitrates, phosphates, and conductivity) in water and sediments from the Chilaw lagoon and its fringe mangroves located on the North-Western coast of Sri Lanka. Interviews were also conducted with local communities (including fishermen) on the social-ecological impacts of pollution in the lagoon ecosystem. Physicochemical analysis was conducted following the APHA standard methods. Statistically significant differences at 95% confidence interval were observed for levels of physicochemical parameters in water and sediment samples, with a horizontal (i.e. length-wise) and vertical (i.e. depth-wise) pollution stratification in the lagoon. Latitude had significant effects on the levels of physicochemical parameters recorded in surface water samples. High levels of pH (pH > 9) recorded in water samples were evidenced by the observation of algal blooms and limited fish catch in the lagoon over the years. Local people report a novel impact of effluent pollution on mangroves, where redworms feed on mangrove leaves. The study, therefore, calls for immediate control of effluent pollution from shrimp farming and other point sources. [ABSTRACT FROM AUTHOR]

Seafood is a rich source of essential compounds for human health, but the consumption of aquatic products that are exposed to environmental pollutants, especially trace metals, comes with risk. Therefore, in this study, the levels of nickel, zinc, and lead in the muscle of shrimp Penaeus semisulcatus caught from the north of the Persian Gulf as a polluted environment were measured, and the health risks were assessed. The results showed that the level of Zn (300.88 ± 2.76 µg/g) in the muscle of shrimp was higher than Ni (6.82 ± 0.10) and Pb (1.10 ± 0.09 µg/g), and the amount of accumulation of all three metals is higher than the allowable limit proposed by the FAO/WHO. According to values of estimated daily intake (EDI) and target hazard quotient (THQ), the consumption of shrimp has no or minimal risk for health. However, the target cancer risk (TR) of Ni (adult, 0.00294; child, 0.00196) indicated that Ni accumulation is associated with carcinogenic risks. These findings may be helpful in the proper management of seafood quality and public health in the Persian Gulf. [ABSTRACT FROM AUTHOR]

Objective: Assess the current daily interim reference level of lead and the amount contained in current mineral and multivitamin-multimineral (MVM) products. Data Sources: PubMed search from 1980 to May 15, 2021, limited to the English language, via the search strategy ((mineral OR multivitamin OR calcium OR iron OR magnesium OR copper OR zinc OR chromium OR selenium) AND (heavy metals OR Pb OR lead)). Study Selection and Data Extraction: Narrative review of studies assessing lead content in mineral or MVM products. Data Synthesis: Products containing different calcium forms (dolomite, bone meal, natural carbonate) have historically had higher lead levels than others (refined carbonate, lactate, gluconate, acetate, sevelamer), but the gap has closed considerably since the year 2000. Although only limited assessments of magnesium and zinc supplements have been conducted, no alarming average lead amounts were found. MVM products assessed since 2007 had low median or mean lead concentrations. However, large interproduct differences exist, with many products having very little lead and some products having concerning amounts. Relevance to Patient Care and Clinical Practice: It is difficult for pharmacists and consumers to know the amount of lead in an actual product unless it is tested in an independent third-party lab. The United States Pharmacopeia and NSF International will provide a seal on the products stating that the products have a low level of lead, but even so, children could receive more lead than the Food and Drug Administration's Interim Reference Level. Conclusions: The threat from lead exposure in mineral and MVM products have diminsihed considerably over time but some products can still have excessive amounts. Without third-party testing, it is difficult for clinicians and consumers to know which outlier products to avoid. [ABSTRACT FROM AUTHOR]

This study analyzed the effects of cadmium (Cd) and lead (Pb) on growth, sexual couples, and histological structures of Artemia franciscana exposed to individual concentrations of these metals and combined. No histological effects were observed at tissue level in digestive, respiratory, nervous, and reproductive systems (i.e., necrosis, loss of regular structure) in individual and mixed applications on A. franciscana for 20 days of exposure. No significant differences (p > 0.05) were determined in final size and growth rate among the organisms exposed to Cd and those of control. For Pb, only the final size (3.59 ± 0.59 mm) of organisms exposed to the highest concentration was significantly lower (p < 0.05) than those of the control (4.53 ± 0.34 mm) group, whereas for the combined experiment, no significant differences (p > 0.05) were observed in final size and growth rate. At all Cd concentrations, mean sexual couples were significantly lower (p < 0.05) than those of the control, as well as for Pb. For the combined experiment (8 μg/L of Cd + 8 μg/L of Pb), sexual couples were not observed, indicating synergism and negative reproduction effects. The results showed that Cd and Pb aquatic environmental regulations (as the Criterion of Continuous Concentration) proposed by the US Environmental Protection Agency (EPA) should include their interactions with other metals. [ABSTRACT FROM AUTHOR]

Metal concentrations in coastal zones are a critical study subject since anthropogenic activities surrounding these zones are increasing and affecting environmental concentrations of metals. Macroalgae have been used as biomonitors since they can act as indicators of metal concentrations in the water column. Tissue samples of three abundant macroalgae species (Spyridia filamentosa, Padina mexicana and Ulva ohnoi) were collected from three sites with different anthropogenic impacts at La Paz Bay and Guaymas Bay, Mexico, during three contrasting seasons (dry, rainy and cold) in the year 2016. Tissue concentrations of iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), nickel (Ni), cadmium (Cd) and lead (Pb) were determined by atomic absorption spectrophotometry. The highest concentrations were found in S. filamentosa inhabiting both bays. The highest Cd and Mn concentrations were recorded in algae from La Paz Bay, while the highest concentrations of Cu, Zn, Pb and Fe were recorded in algae from Guaymas Bay. Metal concentrations varied seasonally; the highest Fe, Cu, Zn, Ni and Pb levels were recorded in the cold season in algae from both bays. S. filamentosa concentrated more Fe, Ni, Cu, Zn and Pb, while P. mexicana and U. ohnoi showed higher Mn and Cd. Therefore, S. filamentosa proved to be the most suitable indicator of metal concentrations, followed by P. mexicana and U. ohnoi. The high metal concentrations recorded in algae from San Juan de la Costa, La Paz Bay, are related to mining activities, whereas those in algae from Guaymas Bay are related to canneries, maritime traffic and others. [ABSTRACT FROM AUTHOR]

In the framework of the biomonitoring programme of the Gulf of Annaba (north-eastern Algeria), this study aims to assess the health status of the Gulf by transplanting the brown mussel Perna perna (Linnaeus 1758) for 12 weeks (June 2017–August 2017) at three sites. The concentrations of copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd) and as well as a battery of enzymatic and non-enzymatic biomarkers were measured in mussels before and after the transplantation period. Furthermore, analysis of trace metals was performed on the surface layer of the sediment of all the sites. A significant increase in the Cu and Pb concentrations in the mussel dry tissues was observed after the transplantation period and followed the order of metal contamination of the surface layer sediments, indicating a relationship between the bioaccumulation of metals and their bioavailability at each site. Unlike those of Cu and Pb, Cd and Zn concentrations did not reach significant levels of bioaccumulation at any of the three study sites. The biomarker response results were complementary to the measured metal concentrations in the mussel tissues and were associated with the metal accumulation index. Metal bioaccumulation in mussels and supporting biomarker response results identified the most important pollution point sources in the area. [ABSTRACT FROM AUTHOR]

The biomagnification of Hg and Se was studied using nitrogen stable isotope analysis during four seasons in a coastal lagoon of the eastern central Gulf of California. This lagoon receives agricultural, municipal, and shrimp aquaculture effluents. The species were categorized into organism groups and presented a significant accumulation of Hg and Se with respect to the sources, while the concentration of both elements in sediment and suspended particulate matter (SPM) was low. Our data confirms the positive transfers (biomagnification factors >1) of Hg and Se in the entire studied food web, and it was structured in five trophic levels across all seasons. Additionally, there were no linear correlations between the molar Se:Hg ratios and the trophic levels of the organism groups. However, the Se:Hg ratios among organism groups were >1, which indicates that there is an excess of Se and that it is not a limiting factor for the detoxification of Hg. [ABSTRACT FROM AUTHOR]

In this study, the anthropogenic sources, the toxic concentration of mercury (Hg), and its spatial distribution were investigated by using fourteen different sediment samples, collected from different locations in Kodaikanal Lake. The research was carried out by evaluating different parameters such as sediment characteristics and the concentration of mercury. The study also involves establishing pollution indices like enrichment factor, index of geo-accumulation, contamination factor, and a potential ecological risk factor for the sediment samples. The characterization studies were done by energy dispersive X-ray fluorescence (EDXRF) and the particle size analyzer to determine the concentration of mercury and to classify the sediments based on the size of the particles, respectively. Statistical analysis and the spatial distribution of mercury were assessed by using two different software tools such as Geostatistic (SPSS Statistics software 17.0) and Geostatistics analyst module (ArcGIS 10.1). The weight percentage of sand, silt, and clay in the collected sediment samples were found to be 61.24 to 83.55%, 15.24 to 36.78%, and 0.92 to 1.98% respectively. The weight percentage of organic matter was from 6.00 to 16.00% and total carbonate content varies from 2.22 to 7.54%. The results obtained from the EDXRF confirmed that the concentration of mercury in the collected samples ranges from 19 to 30 mg/kg of sediment and it indicates that almost all parts of the lake exhibit notably higher concentration. Pearson's correlation coefficient value of 0.74 signifies the association of Hg to the depth of the lake. The high loading values of mud (0.92), Hg (0.91), and water depth (0.86) for PC1 are concerning the 61.10% expressed, the same source for Hg and fine particles and they were, transported and deposited together in deeper depth. The Hg content in the sample to enrichment factor exhibits high to very high (20.95 to 33.81) and index of geo-accumulation with moderate to strongly polluted nature of the sediments (2.34 to 3.00). The fine-grained sediments, water depth, and organic matter were found to be significant controlling factors of Hg distribution in the sediments of the lake. The values of EF and Igeo show that the enhancement of sediment by heavy metal (Hg) was by anthropogenic activities such as discharge of the solid waste from the thermometer factory. Additionally, the contamination factor and potential ecological risk factors were calculated as 47.52 to 75 and 1900 to 3000 respectively, and express the prevalence of very high contamination factors and very high ecological risk. The results also suggest that Hg in lake sediments represents its polluted nature; it could also be influenced by industrial and human activities in the catchment. [ABSTRACT FROM AUTHOR]

Seafood has long been considered a unique source of nutrition. However, increasing trends in consumption of marine products must be considered, especially in potentially polluted environments such as the Persian Gulf. This study was undertaken to analyse the level of heavy metal contamination of nickel (Ni), zinc (Zn), and lead (Pb) in shrimp (Penaeus merguiensis) captured from the northern Persian Gulf. The concentration of heavy metals in the muscle of shrimp followed the order Zn > Ni > Pb. The content of Zn and Ni was higher than recommended standard limits by the FAO/WHO. The combined impact of all metals was lower than the acceptable limit of 1 in shrimp. The carcinogenic risk for Ni was higher than the unacceptable value. In total, our finding indicated no potential health risk from the daily consumption of this species. However, long-term consumption of shrimp can pose a risk of carcinogenic effects of nickel. Continuous monitoring of these trace metals in seafood is necessary to ensure the quality of seafood and food safety. [ABSTRACT FROM AUTHOR]

In the present paper, we investigated the accumulation of six metals in tilapia (Oreochromis nilocticus) and largemouth bass (Micropterus salmoides) as indicators of the environmental pollution present at three constructed dams in the Yaqui River basin in Sonora, Mexico. The La Angostura (ANG), El Cajon de Onapa (ECO), and El Oviachic (OVI) dams are ecosystems under different degrees of anthropogenic stress. The collected fishes were dissected to obtain liver, gonad, stomach, gill, and muscle samples to determine the metal concentrations of Fe, Mn, Ni, Cu, Zn, and Cr. The results of a PERMANOVA showed that the concentrations of Fe, Cu, and Zn were significantly higher in tilapia liver, stomach, and gill tissues compared with those of the largemouth bass. Also, differences were detected between seasons, with the metal concentrations during the dry season being significantly higher than those of the rainy season (p < 0.001). The results of a principal component analysis showed an association between metals, tissues, and dams with significantly higher (p < 0.001) concentrations in tilapia from the ECO dam compared with those from the ANG and OVI dams. The general distribution of metals in the tissues was as follows: liver > stomach-gills > gonads > muscle. Variations in metal concentrations may be indicative of the different sources of anthropogenic stress in each ecosystem. [ABSTRACT FROM AUTHOR]

The present study is based on developing a dual-step ultrasonically modified cloud point extraction (DsUm-CPE) method for enrichment of mercury (Hg) in artificial saliva extract (ASE) of the numerous snuff products (dry and moist snuff, having green, brown and black in colors). This method relies on the complexation of Hg with ammonium O, O-diethyldithiophosphate, followed by the entrapped in nonionic surfactant (Triton X-114) prior to analysis by cold vapor atomic absorption spectrometry (CVAAS). The dispersion of hydrophobic complex in micellar phase was carried out by ultrasound energy, in addition other shaking method, vortex mixer was also applied for comparison purposes, vortex shaking method was also used. Several variables of developed methods, such as complexing agent, Triton X-114, dispersion modes (sonication/vortex shaking), equilibrium temperature, centrifugation time and concentration of back extraction reagent, have been studied. The detection and quantification limit under the optimum conditions were attained as 0.004 and 0.014 µg L−1, respectively. The accuracy for the analysis of total Hg was checked by certified samples of Virginia tobacco leaves (ICHTJ-cta-VTL-2) and both biological samples. The obtained values of all three certified samples have insignificant difference (p > 0.05) among their certified and experimental values. The resulted statistics specified that dry snuff has about fourfold higher contents of Hg as compared to moist snuff, whereas the biological samples of male subject (25 to 60 years) sniffing moist and dry snuff were also analyzed to assess the Hg exposure through their consumption. The biological samples of snuff consumers have about twofold higher concentration of Hg as compared to referents. [ABSTRACT FROM AUTHOR]

Trace metals have been found in sea turtle blood and tissues and may represent a threat to these endangered species. Essential trace metal (Cu, Zn Cd, Pb, As, and Hg) concentrations were determined in blood of adult female, post-nesting olive ridley turtles Lepidochelys olivacea (n = 35) on Ceuta beach, Sinaloa, Mexico. Essential metals (Zn and Cu) analyzed were found in higher concentrations than toxic metals (Cd and Pb), while As and Hg concentrations were below the limits of detection (0.01 μg g-1). Low Pb concentrations (0.09 μg g-1) were previously observed in sea turtles in the Gulf of California. There were no significant correlations found between curved carapace length (61.00–71.00 ± 2.29) vs metal concentrations (p > 0.05). Cd levels were relatively high when compared to other species and populations of sea turtles worldwide and Cd may represent the greatest risk for sea turtles in the Mexican Pacific. Such concentrations of Cd may pose a further risk to sea turtles through bioaccumulation from the nesting female to offspring which may affect embryo development. [ABSTRACT FROM AUTHOR]

In the present study, mercury was selected because of its toxicity. It was detected in the grapevines exposed to mine gallery waters. The potential health risk of mercury in leaves of grapevine those are consumed by human worldwide was investigated. The grapevines were harvested and separated into organs of roots, stems, and leaves. The concentrations of mercury were determined in roots, stems, and leaves. The translocation and bioconcentration factors were calculated. Maximum concentrations of mercury were stem < root < leaf. The health risk potential of mercury on human health was calculated. The estimated daily exposure doses of mercury followed an order for children and adults: dietary > ingestion > inhalation > dermal. The HQ values calculated for exposure ways of dietary, ingestion and inhalation were male < female < children. As a result, it was determined that grapevine exposed to mine gallery waters that cause environmental contamination may cause non-carcinogenic risks on human health. [ABSTRACT FROM AUTHOR]

The bioaccumulation of arsenic (As) in the muscle, liver, kidneys, and brain of the shark Sphyrna lewini was measured in 40 juvenile specimens from southeast Gulf of California. Additionally, the biomagnification factor was calculated through prey items from stomach contents of the analyzed specimens. The concentrations of As (mg kg−1, wet weight) were higher in the muscle (10.1 ± 0.3) and liver (9.4 ± 0.5) than in the brain (4.5 ± 0.3) and kidneys (4.2 ± 0.2), which may be attributed to the biological functions of each tissue. Positive correlations were found between the levels of As in muscle and liver with the biological parameters of S. lewini. Hammerhead sharks feed mainly of teleost fishes with low As values (Clupeidae fishes, 1.1 ± 0.5; Sciaenidae fishes, 1.0 ± 0.6; Scomber japonicus, 1.2 ± 0.6; and Etropus crossotus 2.1 ± 0.4) compared with the predator, indicating biomagnification. Inorganic arsenic (Asi) in muscle was estimated as 3% of the total As, although muscle consumption is unlikely to represent a risk (HQ < 1) in humans. Moreover, the probabilities of developing cancer were estimated as low (3.99 × 10–5 to 3.32 × 10–6). To avoid health risks related to As, a weekly ration must not exceed 69.3 and 484.8 g in children and adults, respectively. [ABSTRACT FROM AUTHOR]

Background. The fish Totoaba macdonaldi is endemic to the Upper Gulf of California. Its migratory movements involve sites with high levels of trace elements in the environment that can accumulate in tissues. In this study, lead (Pb), copper (Cu), cadmium (Cd), zinc (Zn) and iron (Fe) concentrations in male and female totoaba liver and muscle were quantified at various sexual maturity stages along the species' geographic distribution. Methods. Generalized linear models were used to explore associations between trace element concentrations and season of the year, sex/maturity stage, and total fish length. Results. No detectable Pb concentrations were recorded in liver or muscle; Cu, Cd, Zn and Fe contents in totoaba liver and muscle were typical of fish inhabiting areas with no contamination issues and are within international maximum permissible levels for human consumption. Variations in the content of Cd, Cu, Zn and Fe in liver of totoaba seem to be more related to the feeding and reproductive physiology of this species than as result of environmental exposure. Results suggest that consumption of totoaba muscle does not pose a public health risk. Furthermore, depending on the sex/maturity stage of totoaba, this fish's muscle may provide approximately 70% Cu, 60% Zn and 100% Fe of the recommended dietary reference intake. [ABSTRACT FROM AUTHOR]

Lead is a poisonous heavy metal with various known side effects. The effect of opium on raising blood lead concentration (BLC) has been investigated with no general agreement. In Iran, the number of lead poisoning cases has raised among the opium-addicted population. This systematic review and meta-analysis aim to combine the results of previous studies with the Iranian population to investigate the effect of opium on BLC. In this systematic review, PubMed/Medline, Web of Sciences, Embase, and Scopus were searched for studies using the Iranian population to compare the BLC of opium-addicted cases and non-addicted controls till January 2020. A random-effects model was used to pool the results. I-square test was used to assess the heterogeneity of the studies. The effect sizes were standardized mean differences (proxied by Hedges' g) followed by a 95% confidence interval. Of 417 initial articles, 13 studies met the inclusion criteria to be considered in the meta-analysis. The sample size of eligible studies ranged from 40 to 131 (mean 81.83, SD 27.6). All studies were focused on adults with mean age ranged from 33.5 to 65.15 years old (overall mean 49.0, SD 7.66). There were 13 studies included with 18 Hedges' g effect sizes. Using a random effect model, the pooled effect size was gw = 2.48 (95% CI: 1.58–3.39) and statistically significant in favor of opium-addicted participants. Moreover, heterogeneity was 96.6% ( I 2 = 96.6 , Q(17) = 504.95, p < 0.001). For studies with large Hedges' g effect sizes (> 4) identified as outliers and removed from meta-analysis. The pooled Hedges' g effect size reduced to 1.39 (95% CI: 0.94–1.85), still highly significant in favor of higher levels of lead in the opium-addicted group. The funnel plot appeared symmetrical confirmed by Egger's test (t = 1.87, p = 0.088), indicating no publication bias present. [ABSTRACT FROM AUTHOR]

The occurrence and contamination level of seven important toxic metals (Cd, Cu, Co, Cr, Hg, Pb, and Zn) and three additional metals (Al, Fe, and Mn) in the water, sediment, and shrimp muscle in aquaculture areas located in Central Java, Indonesia, were investigated. The results suggest that the majority of metals have higher concentrations in the inlet followed by the outlet and ponds. Cd dissolved in the waters exhibited the highest level in Pekalongan (3.15 ± 0.33 μg L−1). Although Pb was not detected in the water, it was detected in the sediment, and the concentration ranged from 7.6 to 15.40 mg kg−1 dw. In general, the heavy metal concentrations in the sediments were found to decrease in the sequence Al > Fe > Mn > Zn > Cr > Cu > Co > Pb. Concentrations below the effects range low level based on the Canadian sediment quality guidelines were found for Cr, Cu, Pb, and Zn, whereas moderate sediment pollution (25–75 mg kg−1 dw) was observed for Cr (all regions), Cu (except in the Pekalongan region), and Zn (Brebes and Tegal regions) according to the US EPA standard. The status of the waters was evaluated by calculating a pollution index derived mostly from Mn and Zn. The ecological risk (geoaccumulation index (Igeo), contamination factor (CF), pollution load index (PLI), and potential ecological risk index (ERI)) determined in the sediments indicated that all studied areas had low to moderate contamination. The concentrations of all metals in shrimp were generally below the maximum limits for seafood, except for Zn (in all stations), Pb, and Cr (Tegal and Pekalongan). The hazard index values for metals indicated that consuming shrimp would not have adverse effects on human health. [ABSTRACT FROM AUTHOR]

Ecotoxicological research detailing trace metal contamination and seasonal variation in the tissues of northern fishes such as Arctic charr (Salvelinus alpinus) has been poorly represented in the literature beyond examination of mercury. In an effort to address this, anadromous Arctic charr were collected from the Deception River watershed in the late summer and post-winter season, before quantifying seasonal and organotropic variations in dorsal muscle and liver concentrations of arsenic, cadmium, chromium, copper, nickel, lead, and zinc. Potential linkages with biological variables (fork length, age, and somatic condition) and indicators of feeding behavior (δ13C and δ15N) were also assessed. Trace metal organotropism favouring elevation in liver tissue concentrations was exhibited by cadmium, copper, nickel and zinc, while arsenic, chromium and lead exhibited no significant organotropic variation. Seasonal differences in concentrations were metal and tissue dependent, but generally increased in tissues collected from post-winter sampled Arctic charr. Significant correlations with biological and trophic descriptors were also determined to be element and tissue dependent. These parameters, in addition to season, were incorporated into multi-predictor variable models, where variations in trace metal concentration data were often best explained when season, somatic condition, and trophic descriptors were included. These variables were also of greatest relative importance across all considered trace metals and tissue types. These findings suggest that seasonally linked processes have the greatest influence on trace metal concentrations in anadromous Arctic charr. Future metal-related research on Arctic charr and other northern fish species should further consider these variables when evaluating elemental accumulation. [ABSTRACT FROM AUTHOR]