Fluoride levels in river water from the volcanic regions of Cauca (Colombia).

Fluoride concentrations of 0.5 mg/L in drinking water are considered useful for dental caries prevention. However, fluoride concentrations higher than 1.2 mg/L in water can pose a risk of dental fluorosis due to high exposure to fluoride. The objective is to determine the fluoride concentration in water from aqueducts of different Colombian municipalities of Cauca (Popayán, Coconuco, and Puracé) to assess the fluoride dietary intake from the consumption of this water. A total of 66 water samples have been taken from Popayán, Coconuco, and Puracé. Fluoride content was determined by fluoride ion-selective electrode (ISE) potentiometry. The fluoride concentrations recorded in Coconuco and Puracé water were ≤ 0.002 mg/L. The mean fluoride content recorded in the Popayán water was 0.42 mg/L, with its highest concentration in Cauca River water (0.83 mg/L). Considering the admissible intake values, the water from Popayán confers remarkable fluoride intakes, especially in children with high percentages of contribution to the admissible daily intake (46.7% to 7- to 12-month children and 41.5% to 1- to 3-year children). The fluoride content in the water of Coconuco and Puracé does not reach an optimal value (< 0.5 mg/L) for the protective effect against dental caries, while the water of the main Cauca River basin does reach the optimal value. Likewise, the intake of fluoride from the consumption of the analyzed water does not confer any health risk. However, the implementation of monitoring systems for fluoride levels is recommended in order to safeguard the consumer's health.

Metals in commercial fish in the Galapagos Marine Reserve: Contribution to food security and toxic risk assessment.

Metal pollution in the marine environment can damage places with exceptional biodiversity such as the Galapagos Islands. For this reason, it is important to evaluate the toxic risk from metals derived from fish consumption and to perform a nutritional assessment. We sampled 20 individuals of demersal (Caulolatilus princeps and Mycteroperca olfax) and pelagic (Thunnus albacares and Seriolella violacea) species. The levels of the toxic elements (Al, B, Ba, Cd, Ni, Pb and Sr), and the macroelements, microelements and trace elements (Ca, Cr, Fe, K, Li, Mn, Mo, Mg, Na, V and Zn) of species muscle tissue were analyzed by Inductively Coupled Plasma Optical Spectrometry (ICP-OES). Demersal species have higher concentrations of Cr, K, Mg and Mo; while pelagic species have higher levels of Zn. M. olfax could potentially cause Cd toxicity so it is recommended not to ingest more than 86 and 73 g of this species (i.e. roughly, one serving) per week for men and women, respectively. None of the species could be marketed in Europe and the USA due to Cd level exceed the allowed limits by EFSA and FAO. Furthermore, the dietary intake of C. princeps is recommended due to its high concentration of Ca, Na, K, Mg and Cr, while T. albacares is recommended for people with Zn deficiency. However, due to the Cd level in C. princeps it is not recommended to ingest more than five servings per week. We attribute the source of metals in the studied fish from the volcanic origin of the islands rather than from human pollution. This is the first study that thoroughly estimate concentration of metals in commercial fish species and its contribution to food security in the Galapagos.

Trace element and toxic metal intake from the consumption of canned mushrooms marketed in Spain.

Mushrooms are a valuable foodstuff because they are an important source of fiber and essential amino acids, but they have a great capacity to capture metals from substrate. Due to this reason, the content of 14 metals (B, Ba, Cr, Cu, Fe, Li, Mo, Ni, Sr, V, Zn, Al, Cd, Pb) of 100 samples of canned mushrooms grown in Spain were analyzed by inductively coupled plasma atomic emission spectroscopy. Fe (9.55 mg/kg) was the most notable trace element, followed by Zn (2.39 mg/kg). The most abundant toxic metal was Al (17.80 mg/kg). Significant statistical differences between the absorption of metals have been observed when comparing species. Lentinula edodes and Lactarius deliciosus are the species which had the highest metal contents. Taking the average consumption 300 g per day for adults into account, the exposure to trace toxic metals from the consumption of the studied mushrooms does not pose a health risk. However, contribution percentages of Pb (87.6%) and Al (59.2%) found in Lentinula edodes and Pholiota nameko samples, respectively, are near the maximum intake.

Essential and toxic metals in taros (Colocasia esculenta) cultivated in the Canary Islands (Spain): evaluation of content and estimate of daily intake.

Taros are a staple in the diet of many people around the world, and they are an excellent source of minerals. Monitoring the levels of metals in food provides basic information that is useful from the perspectives of safety, regulation, and nutrition. Forty-two samples of taros were randomly obtained from supermarkets, vegetable markets, and farmer's plots on the island of Tenerife (Canary Islands, Spain). The edible portion (pulp) was the only part considered for analysis. Flame atomic absorption spectrometry (FAAS) was used to determine the contents of Na, K, Ca, Mg, Cu, Fe, Mn, and Zn. The levels of Cr, Ni, Cd, and Pb were determined using graphite furnace atomic absorption spectrometry (GFAAS). Mean concentrations (mg/kg) were 565.6 Na, 2947 K, 231.4 Ca, 364.5 Mg, 1.224 Cu, 3.818 Fe, 1.408 Mn, 2.242 Zn, 0.044 Cr, 0.021 Ni, 0.003 Cd, and 0.006 Pb. The mean concentrations of Cd and Pb were well below the accepted European Commission limits (0.1 mg/kg weight for both metals, respectively). Daily consumption of taro (10.41 g taro/person/day) contributes to the dietary intake of essential metals and trace elements, mainly Mg (1.265% in adult women and 1.084% in adult men) and Cu (1.182% for adult men and women). The average daily intakes of Cd (0.031 µg/day) and Pb (0.062 µg/day) from taro were below the legislated respective tolerable weekly intakes (TWIs). Thus, the samples analyzed were considered safe to eat based on their metal concentrations and legislated allowable intakes.

Evaluation of metals in several varieties of sweet potatoes (Ipomoea batatas L.): comparative study.

Sweet potatoes are a staple in the diet of some people and an excellent source of minerals. Metal monitoring in food, like sweet potatoes, provides basic information on safety aspects in regulatory processes as well as nutritional values. One hundred five samples of three varieties of sweet potatoes were randomly obtained from supermarkets, farmers markets, and farmers' plots in Tenerife (Canary Islands, Spain). The edible portion (pulp) was the only part considered for analysis. Flame atomic absorption spectrometry was used to determine the contents of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), while the levels of chromium (Cr), nickel (Ni), cadmium (Cd), and lead (Pb) were determined using graphite furnace atomic absorption spectrometry. The mean concentrations were 500 Na, 4409 K, 564 Ca, 609 Mg, 1.291 Cu, 6.554 Fe, 2.324 Mn, 2.348 Zn, 0.028 Cr, 0.048 Ni, 0.001 Cd, and 0.003 Pb mg/kg, respectively. Potassium presented the highest contents in all varieties of sweet potatoes. Iron was the most abundant microelement. The orange fleshed sweet potato variety offered greater nutritional contributions to the recommended intakes than the rest of the varieties studied. The estimated mean daily intake of Ni (0.72 mg/day) detected in our samples was highly consistent with other studies. Average daily intakes of Cd (0.015 µg/day) and Pb (0.045 µg/day) were below toxicological reference values. In conclusion, the levels of Cd and Pb detected in the sweet potatoes analyzed do not represent any toxicological risk to consumers.

Comparative analysis of metal pollution in the Atlantic Ocean and Mediterranean Sea: insights from Anemonia sulcata study.

In this study, we investigated metal concentrations in Anemonia sulcata specimens from various locations in the Atlantic Ocean and the Mediterranean Sea. A total of 84 individuals were sampled from specific zones, and their tissue samples were processed for metal analysis using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The results revealed notable differences in metal concentrations among the studied regions. The Atlantic Ocean and the Mediterranean Sea were found to have distinct patterns of marine pollution, influenced by a complex interplay of geographical, demographic, industrial, and environmental policy factors. Conversely, the semi-enclosed Mediterranean Sea has a lower natural dilution capacity, leading to the accumulation and prolonged presence of pollutants. Population density and industrial activities in coastal areas play a significant role in pollution disparities between the Mediterranean Sea and the Atlantic Ocean. The Mediterranean coasts, with higher population densities and intensive industrial operations, experience greater strain on marine ecosystems due to increased pollution sources. Additionally, environmental policies and management approaches differ between the two regions, contributing to variations in pollution response and regulation.

Metal content in Sardina pilchardus during the period 2014-2022 in the Canary Islands (Atlantic EC, Spain).

The contamination present in an organism varies depending on biological and oceanographic conditions, so monitoring the same species is of great importance to understand the state of the ecosystem. Fifteen specimens in Sardina pilchardus between 12 and 15 cm in total length were collected during the second half of January of each of the study years (2014, 2016, 2018, 2020 and 2022). Samples were analyzed with Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) to measure metals (Al, Cd, Cu, Fe, Li, Ni, Pb and Zn) in mg/Kg. There was a progressive decrease in Pb content over the period, with the highest concentration being obtained in 2014 (0.086 ± 0.065 mg/kg). Locally important oceanic-atmospheric events may occur in the study period that strongly impact the tissue composition of marine organisms. In this case, discontinuous trends were evident in some of the metal concentrations analyzed in the muscle of European sardine in the Canary Islands.

Metal concentrations in echinoderms: Assessing bioindicator potential and ecological implications.

This study investigates the concentrations of heavy metals and trace elements in five echinoderm species: Holothuria (Platyperona) sanctori, Arbacia lixula, Coscinasterias tenuispina, Ophioderma longicaudum, and Antedon bifida. Given their ecological significance and potential as a food source, understanding the presence and transfer of heavy metals in these species is crucial. Sampling was conducted in 2022 in Canary Islands. Analysis using ICP-OES revealed concentrations of Zn, Cd, Pb, Cu, Ni, Cr, and Fe in mg/kg. The results showed a consistent sequence of metals across all species, with Fe > Zn > Cu > Ni > Cr > Pb > Cd. Holothurians exhibiting the highest levels, followed by sea urchins. Starfish and brittle stars showed similar, lower concentrations, while crinoids exhibited the lowest levels, consistent with their filter-feeding behavior. The findings highlight the potential of holothurians as bioindicators for environmental pollutants. Understanding the role of these echinoderms as bioindicators is essential for assessing ecosystem health and informing conservation efforts in subtropical marine environments.

Environmental Factors Influencing Metal Concentrations in Scomber colias Along the Canary Islands.

A total of 140 specimens of Scomber colias were collected from the Canary archipelago waters during the first semester of 2021, with 20 samples from each of the seven main islands. After analyzing the concentrations of metals (Al, Zn, Cd, Pb, Fe, and Cu) with ICP-OES, significant variations were observed among islands, with specimens from Tenerife and Gran Canaria containing higher levels of Al, Cd, and Pb, while those from Lanzarote and Fuerteventura had elevated levels of Zn, Fe, and Cu. These differences are probably related to greater anthropogenic activity around Tenerife and Gran Canaria coasts, leading to higher pollution levels, and the influence of Saharan dust and African upwelling on Lanzarote and Fuerteventura, enriching the waters with nutrients. Specific management strategies to mitigate marine pollution and continuous monitoring are crucial to safeguard marine ecosystems and to ensure food security.

Impact of natural events on metal bioaccumulation in Anemonia sulcata.

Samples of Anemonia sulcata were collected in 2022 from different areas of the Canary Islands affected by different natural contamination sources, such sandstorms, submarine volcanic activity, continuous rainfall, upwelling and dinoflagellate blooms. Significant differences were observed between the zones for the metals and trace elements analyzed (Al, Zn, Cd, Pb, Ni, Co, Fe, B, Cu, Mg and Li). Anemones from volcanic areas showed higher levels of Cd, Pb and Ni. Individuals from sandstorm areas showed elevated levels of Al, Zn and Fe. Samples collected from areas affected by upwelling processes had higher concentrations of Cu, Mg and Li. Finally, the areas affected by dinoflagellates showed lower levels of Zn, Pb, Fe, Mg and Li. The study reveals how natural phenomena dramatically influence metal accumulation in A. sulcata, which is of great value for anticipating and managing potential problems associated with public health.

Metal and trace element concentrations in cetaceans worldwide: A review.

This bibliographical review is a compilation of different scientific publications that reported data on metal concentrations in the muscle tissue of different species of cetaceans from seas and oceans around the world. Forty-nine scientific articles were selected, published over a fifteen-year period (2006-2021) with data on heavy metals and trace elements. The different groups of cetaceans considered in this study generally presented low concentrations of Cd and Pb. The same cannot be said of Hg. The highest concentrations of Hg were found in the groups of false killer whales. Similarly, the use of these groups of cetaceans as bioindicators of metal contamination shows that the Mediterranean Sea is one of the most metallically contaminated areas in the world. This may be due to the closed nature of the Mediterranean Sea and to the fact that it is also a highly populated and industrialized area.

Impact of the lockdown period during the COVID-19 pandemic on the metal content of the anemone Anemonia sulcata in the Canary Islands (CE Atlantic, Spain).

Anemones, specifically the species Anemonia sulcata, are cnidarians that serve as bioindicators in marine ecosystems, indicating the health of the environment and changes in environmental conditions. Monitoring anemone populations and studying their well-being and distribution provide valuable insights into marine ecosystem conditions. This study aimed to investigate the impact of the SARS-CoV-2 pandemic on the metal content of Anemonia sulcata. Over a six-year period (2017-2022), twenty specimens of Anemonia sulcata were collected in Tenerife, Spain. The results showed that in 2020, during the two-month lockdown in Spain from March to May when tourism was halted, A. sulcata exhibited the lowest concentrations of various metals studied (Al, Cd, Cu, Fe, Pb, and Zn). This finding suggests that the reduced anthropogenic pressure on the coast due to the absence of tourism significantly decreased pollution levels. Therefore, the study emphasizes the importance of promoting sustainable tourism worldwide. The research highlights that minimizing human impact on coastal areas through responsible tourism practices can effectively reduce pollution in marine ecosystems.

Essential Metals and Trace Elements in Cereals and Their Derivatives Commercialized and Consumed in Cape Verde.

Cereals and their derivatives are basic foods in the human diet and a source of minerals, but the content of elements may vary depending on the type of cereal or its processing. The levels of Na, K, Ca, Mg, Fe, Cu, Zn, Mo, Co, and Mn have been determined in 126 samples of cereals and cereal derivatives (rice, corn gofio, corn flour, wheat flour, corn, and wheat) commercialized and consumed in Cape Verde using an inductively coupled plasma-optical emission spectrometer (ICP-OES) after a wet microwave digestion process. Some elements stand out in products such as corn gofio (K), wheat (Mg), and wheat flour (Fe). Negative correlations were found between Mo-Na and Na-Zn that could suggest interference between these elements. Bearing in mind the dietary intake evaluation and the guideline values provided by EFSA (European Food Safety Authority) or FAO (Food Authority Organization), the consumption of wheat (100 g/day) provides a notable contribution of Mo, Mn, Fe, and Mg. Considering the nutritional value of the analyzed essential and trace elements, the consumption of different cereals and their derivatives should be promoted.

Pesticide Residues in Bananas from the Canary Islands.

There are a large number of pests which are detrimental to plant production, specifically to banana cultivation, and the use of pesticides is the main method of control of these pests. Therefore, the number of active substances in pesticides has been steadily increasing since before the Second World War. There is growing consumer concern about the health effects of pesticide residues and there is certainly evidence of a link between pesticide exposure and the prevalence of chronic diseases. Therefore, it is of particular interest to study the presence of pesticide residues in bananas and their toxicological, agricultural and legal implications. In this study, the content of pesticide residues in bananas produced in the Canary Islands during a ten-year period from 2008 to 2017 was determined. A total of 733 samples of bananas were analysed during the study period, in which 191 different active substances were investigated, involving 103,641 assessments. The samples analysed were selected in such a way that they are representative of the banana sector in the Canary Islands as a whole, taking into account geographical and climatic factors, cultivation methods and the processing of bananas in packaging, which are the differentiating factors in the use of pesticides. The reference parameter for the residue investigation is the MRL (maximum residue limit).

Whey Protein Dietary Supplements: Metal Exposure Assessment and Risk Characterization.

Protein supplements (PS) are trendy foods, especially those made from whey. In addition to providing protein, these products are a source of metals, providing essential elements (Na, K, Mg, Ca, Mo, Mn, Fe, Co, Cu, and Zn) and other potentially toxic elements (Al, B, Sr, V Ba, and Ni). In this study, 47 whey PS samples were analyzed for mineral elements by ICP-OES, and their dietary exposures were assessed for three consumption scenarios. Elements found in higher concentrations were K (4689.10 mg/kg) and Ca (3811.27 mg/kg). The intake of 30 g PS (average recommended amount/day) provides about 20% of the established reference value (NRI) for Cr (18.30% for men and 25.63% for women) and Mo (26.99%). In a high daily consumption scenario (100 g PS/day) and when the maximum concentrations are considered, Cr, Zn, Fe, Mo, and Mg dietary intakes of these metals exceed the daily recommended intakes and could pose a risk. The daily intake of 30, 60, and 100 g of whey PS for 25 years does not pose a health risk since the hazard index (HI) is less than one in these consumption scenarios, and the essential elements contributing most to HI are Co, followed by Mo and Cr. It is recommended to improve the information to the consumers of these new products. Furthermore, to help in the management and prevention of these potential health risks, it would be advisable to improve the regulation of these dietary supplements and their labeling.

Interdecadal variations of the mercury content in Scomber colias in Canary Islands.

Mercury is a very dangerous toxic metal that bioaccumulates very easily in organisms, and it migrates through the food web. The specimens studied in this study were Scomber colias. In the results obtained for the years 1973, 1992, and 2021, the concentration of mercury has been decreasing considerably over the decades, starting with 0.23 ± 0.04 mg/kg in 1973, and having less than half in 2021 with 0.11 ± 0.01 mg/kg. This may be due to the laws imposed by the countries against pollution and to a greater extent in the elimination of mercury; thanks to these measures it has been possible to reduce the concentration of mercury by half in S. colias. Otherwise, the conservation and availability of historical collections of living beings should be considered an unvalued source of information which could help to monitor legislation measures launched to ameliorate the human impact on the natural environment.

Proteins and Minerals in Whey Protein Supplements.

Sports nutrition supplementation is a widespread practice. Whey protein supplements contribute not only to protein intake but also to dietary exposure to minerals. The labelling present provides the percentage of protein and rarely refers to other components, such as potentially toxic elements such as B, Cu, Mo, Zn, and V that present tolerable upper intake levels set by the European Food Safety Authority. The percentage of protein declared on supplement labelling was checked using the Kjeldahl method, and the levels of Ca, Mg, K, Na, Ba, B, Co, Cu, Cr, Sr, Fe, Li, Mn, Mo, Ni, V, Zn, and Al were analyzed by ICP-OES with the aim of characterizing the protein and mineral contents of isolate and concentrate whey protein supplements representative of the European market. The protein content was 70.9% (18-92.3%) and statistically significant differences were observed between the declared and real protein percentages. Among the minerals, K (4689.10 mg/kg) and Ca (3811.27 mg/kg) presented the highest levels, whereas Co (0.07 mg/kg) and V (0.04 mg/kg) showed the lowest levels. It was concluded that the quality and safety of these products needs to be monitored and regulated. A high degree of non-compliance with labelling claims was detected. Furthermore, the contributions to the recommended and tolerable intakes among regular consumers need to be assessed.

Trace and macro elements concentrations in the blood and muscle of loggerhead turtles (Caretta caretta) from the Canary Islands, Spain.

Sea turtles can bioaccumulate heavy metals and trace elements over the years, therefore they can be used as bioindicators of pollution in the marine environment. The aim of this study was to analyze seventeen elements in blood and muscle of Caretta caretta from the Canary Islands and compare these concentrations in the two tissues. Thirteen blood samples and six muscle samples were collected from loggerhead turtles admitted to the Rescue Center of La Tahonilla. The samples were processed through microwave digestion and incineration. For the study of the data, a descriptive statistical analysis and a PERMANOVA were performed. All individuals in this study were juveniles (size <70 cm). The results of this study differ from previous studies on loggerhead sea turtles. All the elements analyzed were detected, with Na having the highest concentration in blood (75,379 ± 30,066 mg/kg) and muscle (222,626 ± 156,049 mg/kg). Statistically significant differences were found between the concentration of Al, B, Ba, Ca, Fe, K, Na, Sr, V and Zn in each tissue analyzed. Compared to other studies, a higher Cu concentration was found both in blood (252.9 ± 114.4 mg/kg) and in muscle (416 ± 247.8 mg/kg). This study has provided new data on pollutants in loggerhead sea turtles and increased the information available for different geographic areas, although more studies are needed to understand the effects and impact of these pollutants on sea turtles.

Dietary Exposure to Toxic Metals (Cd, Pb and Hg) from Cereals Marketed in Madeira and the Azores.

Cereals and cereal-based foods continue to be basic foods in all diets. Despite being known for their high nutritional value; they can also contain contaminants (hazards) such as toxic metals. This study assesses the Cd, Pb and Hg dietary exposure from cereals and derivatives marketed in Madeira and the Azores and characterizes the risks by evaluating the Cd and Hg intake contributions to the tolerable intakes and by estimating the Margin of Exposure (MOE) in the case of Pb. In Madeira, metals follow the descending order of Cd > Pb > Hg. Cd stands out as having the highest levels (0.307 mg Cd/kg in oats; 0.237 mg/kg in rye). High levels of Pb (0.347 mg/kg) were also detected in rye. Regarding total mercury, rice stands out (0.0013 mg/kg) followed by wheat (0.001 mg/kg). While all cereals and derivatives except maize consumed in Madeira exceed the maximum value of Cd allowed by the EU, 50.0% of the rye and 25.0% of the corn flour samples exceeded the European Pb limit. The daily consumption of 100 g of oats, rye flour and rye represent high contributions to the TWI of Cd (93.2 - 120%). The MOE values of Pb from the consumption of rye (100 g/day) are 1,294 (nephrotoxic effects) and 3,082 (cardiotoxic effects). In the Azores, corn flour (0.72 mg Pb/kg) stands out with 85.7% of the samples exceeding the maximum Pb EU limit and MOE values of 626 (nephrotoxic effects) and 1,490 (cardiotoxic effects). Regular daily consumption of corn flour makes a low (< 10%) contribution to the Cd TDI. In conclusion, the Pb exposure from the consumption of cereals and derivatives could have toxic effects such as nephrotoxicity or cardiotoxicity in adults. The results highlight the need to set up monitoring and surveillance programs for the safety of cereals and their derivatives in Madeira and the Azores in terms of lead and cadmium.

Risk Assessment and Characterization in Tuna Species of the Canary Islands According to Their Metal Content.

Bioaccumulation is the process by which living organisms accumulate substances, such as pesticides, heavy metals, and other pollutants, from their environment. These substances can accumulate in the organism's tissues over time, leading to potential health risks. Bioaccumulation can occur in both aquatic and terrestrial ecosystems, and can have a significant impact on the health of both humans and wildlife. The objective of this study is to find out if the concentrations of metals in the tuna species of the Canary Islands are suitable for human consumption and if they pose a health risk. Fifteen samples of Acanthocybium solandri, Katsuwonus pelamis, Thunnus albacares, Thunnus obesus and Thunnus thynnus present in canaries were analyzed. Ten grams of muscle were taken from each specimen and the metals Al, Cd, Cr, Cu, Fe, Li, Ni, Pb and Zn were determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The tuna species that presented more metals with a higher concentration compared to the others was T. thynnus, reaching up to 100 times more than the other studied species in Fe content with 137.8 ± 100.9 mg/Kg, which may be due to the fact that it is the largest species that reaches ages of more than fifteen years. The species Thunnus thynnus should not be suitable for commercialization according to the current legislation on the concentrations of Cd in blue fish, since 75% of the specimens studied exceeded the concentration legislated for Cd. A total of 40% of the studied specimens of this this species exceeded the legislated values for the concentration of Pb in oily fish meat, so this species must be monitored to ensure that it does not pose a risk to human health.