Human Exposure to Toxic Metals (Al, Cd, Cr, Ni, Pb, Sr) from the Consumption of Cereals in Canary Islands

Intraspecific variation in tomato: Impact on production quality and cadmium phytoremediation efficiency in intercropping systems with hyperaccumulating plant

Intercropping with hyperaccumulators can facilitate the safe utilization of cadmium-contaminated soil. However, the effectiveness of this approach is influenced by plant species and varieties, which necessitates research on optimal plant consortia. In this study, 8 tomato varieties (3 cherry tomatoes and 5 common large-fruit tomatoes) were intercropped with Sedum alfredii in a moderately Cd-contaminated vegetable field. The results showed that the Cd concentration in the fruits of common large-fruit tomato varieties under monoculture was 1.03-1.50 mg/kg, while that in the fruits of cherry tomato varieties was 0.67-0.71 mg/kg. After intercropping with S. alfredii, the fruit Cd concentrations of Hangza 501, Hangza 503, and Hangza 108 decreased by 16.42 %, 19.72 %, and 6.76 %, respectively, while those of the other varieties significantly increased, except for those of Hangza 8. In contrast, the shoot Cd concentration of cherry tomatoes was greater than that of large-fruit tomatoes under monoculture. Furthermore, a significant increase in the shoot Cd concentration was noted in the Hangza 501, Hangza 503 and Hangza 603 plants following intercropping. Additionally, intercropping with S. alfredii increased the concentration of soluble sugars in the fruits of Hangza 8, Hangza 501, Hangza 503 and Hangza 603 by 4.66 %, 17.91 %, 10.60 % and 17.88 %, respectively. Intercropping with tomatoes resulted in a decrease in both the biomass and Cd uptake of S. alfredii. Interestingly, the inhibitory effect on S. alfredii was less pronounced when intercropped with cherry tomatoes than when intercropped with large-fruit tomatoes. Among the intercropping treatments, S. alfredii exhibited the greatest total Cd accumulation (0.06 mg/plant) when intercropped with Hangza 503. In conclusion, the cherry tomato variety Hangza 503 was the most suitable for intercropping with S. alfredii and can be used safely for vegetable production and simultaneous phytoremediation of polluted soil. Our findings suggest that strategic selection of tomato varieties can optimize the effectiveness of "phytoextraction coupled with agro-safe production" technology for managing soil Cd concentrations.

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.

Integrated Assessment of Pb(II) and Cu(II) Metal Ion Phytotoxicity on Medicago sativa L., Triticum aestivum L., and Zea mays L. Plants: Insights into Germination Inhibition, Seedling Development, and Ecosystem Health

Environmental pollution with heavy metals has become a problem of major interest due to the harmful effects of metal ions that constantly evolve and generate serious threats to both the environment and human health through the food chain. Recognizing the imperative need for toxicological assessments, this study revolves around elucidating the effects of Pb(II) and Cu(II) ions on three plant species; namely, Medicago sativa L., Triticum aestivum L., and Zea mays L. These particular species were selected due to their suitability for controlled laboratory cultivation, their potential resistance to heavy metal exposure, and their potential contributions to phytoremediation strategies. The comprehensive phytotoxicity assessments conducted covered a spectrum of critical parameters, encompassing germination inhibition, seedling development, and broader considerations regarding ecosystem health. The key metrics under scrutiny included the germination rate, the relative growth of root and stem lengths, the growth inhibition index, and the tolerance index. These accurately designed experiments involved subjecting the seeds of these plants to an array of concentrations of PbCl2 and CuCl2 solutions, enabling an exhaustive evaluation of the phytotoxic potential of these metal ions and their intricate repercussions on these plant species. Overall, this study provides valuable insights into the diverse and dynamic responses of different plant species to Pb(II) and Cu(II) metal ions, shedding light on their adaptability and resilience in metal-contaminated environments. These findings have important implications for understanding plant-metal interactions and devising phytoremediation strategies in contaminated ecosystems.

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.

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.

Heavy Metal Contamination in Leafy Vegetables Grown in Jazan Region of Saudi Arabia: Assessment of Possible Human Health Hazards

The food chain, through vegetable consumption, is considered to be an important route of heavy metal exposure. Therefore, in this study, heavy metal concentrations in leafy vegetables grown in the Jazan region of Saudi Arabia were assessed using an ICP-MS. Lettuce, radish, mint, parsley and jarjir (Arugula) were selected for study and subjected to digestion using HCl. The results indicated that the Fe level was highest in all vegetables, while jarjir was the most contaminated vegetable. However, no tested metal exceeded the maximum permissible limits set by the FAO/WHO and European Committee. The possible health hazards associated with the exposure to metal contaminants via vegetable consumption were evaluated by estimating target hazard quotient (THQ) values, and the results revealed that the vegetables grown in close proximity of Jazan city were the most contaminated and those in Darb the least. However, the daily intakes of all the tested metals were well below the corresponding oral reference doses (RfDs), and the THQ values were less than unity, suggesting that the vegetables grown in the studied region were safe and the heavy metal exposure via vegetable consumption was unlikely to cause adverse effects to the local inhabitants of the region.

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.

The elemental composition of small mammals in a commercial orchard-meadow system

We analyze concentrations of various elements in small mammals from commercial orchards and berry plantations and test differences between them depending on species, individual body mass, age, gender, type and age of crop and intensity of applied agricultural measures. Skinned front legs (muscle and bones) were used to register the presence and concentration of Ca, Cd, Mo, Ni, Se, Ag, As, Be, Bi, Co, Cr, Cu, Fe, Ga, Mg, Mn, Pb, Sr, U, V and Zn. The most abundant species were common vole (Microtus arvalis), yellow-necked (Apodemus flavicollis) and striped field (A. agrarius) mice. The maximum recorded concentrations exceeded the minimums by 1.7-7.7 times in Mg, Zn, Cu, Ga, Ni and Ca, and 11.0-23.2 times in Mn, Be, Mo, Co, Sr, V, Pb and As. The hypothesis that the use of fertilization and pesticides in commercial orchards should induce differences in the elemental concentrations between crop areas and control habitats was confirmed by the higher concentrations of Cu, Mn, Bi, Co, Cr, Fe, Ni, Sr and Pb in rodents from the crop areas. Spatially controlled generalized linear mixed model confirmed the cumulative influence of species and crop, explaining 30-80% of the distribution of Ca, Ni, Co, Cu, Ga, Mn, Pb and U. The effect of species and the age of the individual was significant for Ni, Co, Cu, Fe, Ga, Mn and Pb, while effect of gender was not expressed. Depletion of Cu in older individuals was found in all three species. With species as a grouping factor, the effect of crop type and the intensity of agricultural practices were significant factors in the accumulation of Ca, Ni, Co, Cu, Ga, Mn and Pb, while effect of crop age was not expressed. The obtained elemental concentrations in rodents indicated orchards to be cleaner than heavy polluted areas.