Temporal trend of the dietary exposure to metals/metalloids: A case study in Tarragona County, Spain

Mechanistic Insights Into the Role of Selenoprotein M in Nickel-Induced Lung Fibrosis

Long-term exposure to high concentrations of nickel (Ni) compounds could cause damage to lung tissue and increase the risk of lung and respiratory cancers. Selenoprotein M (SELENOM) plays a crucial role in antioxidant and anti-inflammatory activities. However, the relationship between SELENOM and the mechanism of Ni-induced pulmonary fibrosis in mice remains unknown. Our study explored the regulated mechanism of SELENOM in Ni-induced pulmonary fibrosis. Wild-type and SELENOM knockout C57BL/6N male mice were randomly divided into Wild-control and Wild-Ni groups, which were administered distilled water and NiCl2 (10 mg/kg) by gavage for 21 days. Lung tissues were then collected for histological analysis using hematoxylin-eosin (H&E) and Masson staining, as well as for electron microscopic examination. Firstly, light microscopy revealed inflammatory cell infiltration, alveolar collapse, and alveolar wall thickening in the lung tissue of SELENOM knockout mice. Electron microscopy of lung tissue showed a large accumulation of fibroblasts, proliferation of collagen fibers, and dense collagen deposition, indicating that SELENOM knockout increased lung injury in Ni treatment. Secondly, SELENOM knockout increased malondialdehyde (MDA) levels while decreasing superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and glutathione peroxidase (GSH-Px) activities. Furthermore, Ni exposure and SELENOM knockout significantly upregulated protein and mRNA levels of epithelial-mesenchymal transition (EMT) markers α-SMA, COL-I, TGF-β1/Smad, and JAK2/STAT3 signaling pathway in the lung. These findings suggest that SELENOM knockout promotes EMT and exacerbates pulmonary fibrosis and inflammation through activation of the TGF-β1/Smad and JAK2/STAT3 signaling pathways. In summary, our study highlights the critical role of SELENOM in mitigating Ni-induced pulmonary fibrosis and provides insights into potential therapeutic targets for Ni-induced lung diseases.

Levels of Rare Earth Elements in Food and Human Dietary Exposure: A Review

Rare earth elements (REEs) are a group consisting of the following 17 metals: Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Pm, Sc, Sm, Tb, Tm, Y and Yb. In the current century, the number of applications of REEs has significantly increased. They are being used as components in high technology devices of great importance industrial/economic. However, information on the risk of human exposure to REEs, as well as the potential toxic effects of these elements is still limited. In general terms, dietary intake is the main route of exposure to metals for non-occupationally exposed individuals, which should be also expected for REEs. The current paper aimed at reviewing the studies -conducted over the world- that focused on determining the levels of REEs in foods, as well as the dietary intake of these elements. Most studies do not suggest potential health risk for consumers of freshwater and marine species of higher consumption, or derived from the intake of a number of vegetables, fruits, mushrooms, as well as other various foodstuffs (honey, tea, rice, etc.). The current estimated daily intake (EDI) of REEs does not seem to be of concern. However, considering the expected wide use of these elements in the next years, it seems to be clearly recommendable to assess periodically the potential health risk of the dietary exposure to REEs. This is already being done with well-known toxic elements such as As, Cd, Pb and Hg, among other potentially toxic metals.

Concentrations of polychlorinated naphthalenes in food and human dietary exposure: A review of the scientific literature

In general, for most environmental persistent organic pollutants (POPs), dietary intake is the main way of exposure. Polychlorinated naphthalenes (PCNs) are a family of two-ringed aromatic compounds, which are ubiquitous environmental contaminants, being structurally similar to PCDD/Fs and PCBs. Although the production and use of PCNs were banned in the USA and Europe some decades ago, due to their persistent properties, PCNs remain still present in the environment, being able to enter the food chain. The present paper was aimed at reviewing the results of the studies focused on determining the levels of PCNs in foods. The human dietary intake of these compounds was also reviewed with the few available data. The information on the levels of PCNs in foodstuffs is currently more abundant than that found in a previous review (Domingo, 2004). Since then, China is the country that has contributed with the greatest number of studies. The results of most surveys seem to suggest that human health risks of PCNs due to dietary exposure should not be worrying. However, because of the important differences in the methodology of the published studies, the comparison of the results is not easy, although there seems to be a general trend towards a decrease in the levels of PCNs in foods. In the next few years, a continued reduction of the environmental levels of PCNs is still expected. Therefore, a direct repercussion of the concentrations of these pollutants in foodstuffs must be also noted. Consequently, a reduction of the dietary exposure to PCNs should be expected. Anyway, to establish the tolerable dietary intake of PCNs is a key issue for assessing human health risks of these pollutants.

Dietary exposure to metals/metalloids and persistent organic pollutants in Spanish preschool and primary school children

Diet is a primary source of pollutant exposure. Given children's vulnerability to their effects, this study assessed dietary intake of metals/metalloids and different persistent organic pollutants in children in Tarragona (Spain), compared it with the health-based guideline values (HBGV), and identified the main dietary sources. The analysis included 533 preschoolers and 443 primary school children from the EPINED and ECLIPSES studies. Dietary intake of cadmium (Cd), methylmercury (MeHg), lead (Pb), inorganic arsenic (inAs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DL-PCBs), and non-dioxin-like polychlorinated biphenyls (NDL-PCBs) was estimated using validated food frequency questionnaires and a database from the Catalan Agency for Food Safety. Preschoolers and primary school children exceeded the relevant reference value for InAs and DL-PCBs. Only preschoolers exceeded the limit for MeHg and PCDD/Fs. Cd, Pb, and NDL-PCBs intakes did not exceed the limits in either age group. Salted cereals/potatoes were the main source of InAs; fish for MeHg and DL-PCBs; and milk/yogurt for PCDD/Fs, followed by white fish in preschoolers and fatty fish in primary school children. The findings highlight that dietary exposure to some pollutants poses a significant risk to these children, emphasizing the need for public health policies to reduce pollutants in their diets.

Human Exposure through the Diet to Arsenic and Other Toxic Elements: A Literature Review of Scientific Studies Conducted in Catalonia, Spain, in the Current Century

Human exposure to arsenic and other toxic elements such as cadmium, lead and mercury may lead to a wide range of adverse health effects. In relation to this, it is well established that the diet is the main route of exposure to both essential and toxic trace elements. In recent years, the levels of toxic elements in foodstuffs have been measured in numerous studies conducted all over the world. Scientific databases show that, in the current century, China and Spain have been the countries where the most surveys on this topic have been carried out. Regarding Spain, Catalonia is the region where most studies aimed at determining the concentrations of trace elements in food have been performed. The objective of this paper was to review the studies carried out in Catalonia on the concentrations of As and toxic metals (including Cd, Hg and Pb) in food, as well as their estimated dietary intakes (EDIs). The results of total diet studies (TDSs) and duplicate diet (DD) studies have been included. For most toxic elements, a continued reduction in the EDI has been observed. This reduction is associated with a decrease in their concentrations in food, and with certain changes in dietary habits. Fish and seafood is the food group showing the highest content of toxic elements. However, none of the adult groups exceeded-in general-the safety thresholds for As, Cd, Hg and Pb established by the European Food Safety Agency (EFSA).

Air concentrations of trace elements in a municipality under the influence of Tarragona petrochemical complex: Human health risks

One of the largest petrochemical complexes of southern Europe is located in Tarragona County (Catalonia, Spain). Despite environmental monitoring is routinely conducted in the area, the long-term occurrence of airborne trace elements has been poorly investigated. In the present study, the concentrations of arsenic (As), cadmium (Cd), chromium (Cr), nickel (Ni), lead (Pb) and vanadium (V) were analysed in air samples collected in El Morell, a town potentially impacted by the petrochemical. Air samples were simultaneously collected in the town of Cambrils, as a background site. Meteorological data and retro trajectories analysis were used to evaluate the impact of the petrochemical industry on the levels of trace elements in air. Subsequently, human health risks due to inhalation exposure to the trace elements were also assessed. Except for V, air concentrations were significantly higher near the oil refinery than the background levels. Human health risks were also estimated to be higher in the vicinity of the petrochemical complex. In turn, air inhalation of Pb and V was higher than their dietary intakes. The present data should be considered only as preliminary, since the sampling was taken during only three weeks, which is an insufficient period to extract reliable conclusions. Further long-term studies should be focused on assessing the influence of temporary variables, such as meteorological conditions and fugitive or sporadic emissions.

Dietary intake of metals, metalloids, and persistent organic pollutants in Spanish pregnant women. ECLIPSES study

OBJECTIVE

This study aimed to describe dietary intake and important dietary sources to pollutants as well as to identify maternal socio-economic and lifestyle factors associated with high intake during pregnancy in women residing in a Mediterranean city with heavy industrial activity.

METHODS

Dietary intake during pregnancy of As, InAs, Cd, MeHg, Pb, PCDD/Fs, DL-PCBs, and NDL-PCBs in 701 pregnant women participating in the longitudinal ECLIPSES study was calculated based on a 45-item food-frequency questionnaire and a database of pollutants in food of the Catalan Food Safety Agency. Details on socio-economic, lifestyle, and anthropometric variables were also collected.

RESULTS

The mean dietary intake of pollutants per day and the food group that contributed the most (%) was: 286.51 μg of As (71.27% from white fish), 4.14 μg of InAs (70.16% from cereals-tubers), 6.27 μg of Cd (47.51% from seafood), 5.00 μg of MeHg (52.88% from blue fish), 3.32 μg of Pb (30.15% from cereals-tubers), 9.93 pg of PCDD/Fs (from many food categories), 18.39 pg of DL-PCBs (59.74% from blue fish) and 181.00 ng of NDL-PCBs (44.58% from blue fish). Adjusted multivariate analysis revealed that older age was associated with high As intake, higher educational level was related to low InAs, Cd, and DL-PCBs intake, and alcohol use and smoking were linked with high Pb intake.

CONCLUSION

The dietary intake of pollutants including As and DL-PCBs among pregnant women exceeds or almost reaches the EFSA safety threshold. These findings support the urgent need for local governments to pay special attention to this situation and develop specific prevention strategies for this vulnerable group.

Bioavailability-based risk assessment of various heavy metals via multi-exposure routes for children and teenagers in Beijing, China

Assessing the health risks of sensitive population, such as children and teenagers, through multiple exposure routes (MERs) such as ingestion, inhalation, and dermal contact is critical for policy creation that protects or reduces exposure to pollutants for all populations. Heavy metal (HM) contents in food and environmental media in Beijing, capital of China, were collected. Furthermore, on the basis of considering the bioavailability of HMs, we evaluated the multiple environmental routes and health risks to HMs in children and teenagers of eight age groups (2-<3, 3-<4, 4-<5, 5-<6, 6-<9, 9-<12, 12-<15, and 15-<18) in Beijing, China by Monte Carlo simulation approach. The main findings are as follows: lead exposure in children aged 2-<3 years exceeds the exposure dose (0.3 μg·kg-1·d-1) of 0.5 point reduction in intelligence quotient. Moreover, children aged 2-<3 and 6-<9 years have relatively high non-carcinogenic risk (NCR) of 1.32 and 1.30, respectively. The carcinogenic risk (CR) for children aged 6-<9 and 9-<12 years is 2.73×10-6 and 2.39×10-6, respectively. Specifically, the contributions of oral ingestion, dermal contact, and inhalation to the NCR were 69.5%, 18.9%, and 11.6%, respectively. Moreover, the combined NCR contributions of copper, cadmium, mercury, and arsenic (As) were about 69.4%. The contributions of the above three routes to the CR were 93.4%, 4.1%, and 2.5%, in that order, with the largest CR contribution of As being about 92.0%. This study can provide new ideas for accurately assessing the exposure and health risks of HMs in the population, and we believe that it is necessary to update the national standards for food and soil based on the bioavailability of HMs.

Rare earths and other elements content in hen eggs sold in Italy: comparison among main types of farming methods and consumer's health risk assessment

Recently, in Italy, consumers are choosing hen eggs from farming systems with higher ethical value, due to their perception of a related higher quality and safety. The purposes of this study were to evaluate the existence of differences in elemental content in Italian eggs from organic, barn, and caged hen farming methods and to determine the related potential consumer exposure risk to inorganic contaminants due to the consumption of eggs. One hundred seventy-six egg samples were collected and analyzed using Q-ICP-MS to investigate the content of 14 elements (Pb, As, Hg, Cd, Tl, Fe, Zn, Mn, Cu, Se, Co, Ni, V, and Cr) and 13 rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb). The scenarios of exposure to rare earth and other elements from eggs were estimated for three age groups of consumers. The daily intake values were always lower than the respective safety reference values. In conclusion, Italian hen eggs contain low levels of rare earth and other elements, and therefore, their consumption does not represent a risk of exposure. Finally, no significant differences in contaminants between conventional and organic farming methods were found.

Environmental and dietary determinants of metal exposure in four-year-old children from a cohort located in an industrial area (Asturias, Northern Spain)

Urine samples from four-year-old children located in a heavily industrialized zone in Asturias (Spain) were collected between 2009 and 2012 (n = 334). Vanadium (V; median 54 μg/g creatinine), cobalt (Co; 1.0 μg/g c.), nickel (Ni; 3.8 μg/g c.), copper (Cu; 22 μg/g c.), zinc (Zn; 590 μg/g c.), arsenic (As; 64 μg/g c.), selenium (Se; 49 μg/g c.), molybdenum (Mo; 110 μg/g c.), cadmium (Cd; 0.27 μg/g c.), antimony (Sb; 1.0 μg/g c.), cesium (Cs; 14 μg/g c.), barium (Ba; 2.6 μg/g c.), thallium (Tl; 0.55 μg/g c.) and lead (Pb; 1.9 μg/g c.) were analysed. Comparison with children from other sites showed that this Asturias cohort was characterized by high levels of V, As, Sb, Cs and Tl. The concentrations of Co, Ni, Zn, Cu, Mo, Se, Cd, Ba and Pb were within the range of other cohorts. Terrestrial dietary items were most strongly related to increased urinary concentrations of metals in children, e.g., red meat with Ba and Ni, pasta/cereal with Ni and Zn, sweets with Zn, Co, and Cu, eggs with Mo, Cd, and Cs, and dairy products with Co and Sb. Seafood was the second group of dietary items significantly related to increased metals, e.g., shellfish with Ba, Cs, Pb, and V, fatty fish with As, and lean fish with As and Se. In contrast, higher fruit intake was significantly associated with decreased Cu and Sb, and higher legume intake with decreased Cu, Se and Cs. Higher intakes of other dietary items also led to significant decreases in some metals, such as vegetables and lower concentrations of Se and Mo, and dairy products with decreases in Cu and As. These negative correlations implied very low concentrations of the mentioned metals in these foods. Higher exposure to traffic was associated with higher concentrations of Ba, present in brake components. Children living outside urban areas had higher concentrations of Se. No association of metals with smoking in the family was found.

Safety of Lemna minor and Lemna gibba whole plant material as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on Lemna minor and Lemna gibba whole plant material as a novel food (NF) pursuant to Regulation (EU) 2015/2283. Lemna minor and Lemna gibba are aquatic plants commonly named water lentils. The NF is produced by cultivation of Lemna minor and Lemna gibba plants, washing with water and heat treatment. The main constituents of the NF are water, protein and fibre. The Panel notes that the concentration of trace elements and contaminants in the NF is highly dependent on the conditions of cultivation of the plant and the fertiliser composition. The NF is intended to be used as a vegetable, similar to other leafy vegetables. The target population is the general population. The Panel considers that, with the exception of concerns related to the manganese intake, taking into account the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The Panel considers that the risk that the consumption of the NF may trigger allergic reactions in humans is low. The Panel concludes that the NF, in consideration of its proposed uses and the concentration of manganese as compared to the normally present concentration of manganese in other leafy vegetables, may be of safety concern, therefore, the safety of the NF cannot currently be established.

Human dietary exposure to metals in the Niger delta region, Nigeria: Health risk assessment

The contamination profile and the human health risk assessment of various heavy metals (Cd, Cr, Mn, Ni and Pb) in vegetable oils, palm oils, butter and shea butter purchased from the Nigerian market were evaluated. Univariate and multivariate analyses including the principal component analysis (PCA), hierarchical cluster analysis (HCA) and heat map visualization were used to evaluate correlation, similarity and source of metals. Dietary intake and dermal absorption through the application in skin were also assessed. The heavy metals 5th and 95th percentile interval range (in mg/kg) were 0.003-0.208, 0.003-0.392, 0.003-1.344, 0.003-0.369 and 0.006-0.531 for Cd, Cr, Mn, Ni and Pb, respectively. Concentrations of Cr and Mn were significantly different across sample categories, being the levels of Mn and Ni positively correlated in both oil and butter samples. The result of PCA, HCA and heat map revealed the profile of heavy metals in oils was different from that of butters, with Pb mainly associated to oils, and Cd, Cr, Mn and Ni to butters. In some samples, the international maximum levels for Cd, Ni and Pb in edible oils were exceeded. Cadmium and Pb dietary intake through Nigerian oils and butters should not be considered negligible for human health protection.

Residual Levels of Mercury, Cadmium, Lead and Arsenic in Some Commercially Key Species from Italian Coasts (Adriatic Sea): Focus on Human Health

This study provides information on the potential human health risk of Hg, Cd, Pb and As exposure from consumption of two fish species (Umbrina cirrosa and Sciaena umbra) in the general population and in high-level fish consumers. The concentrations did not show significant differences between the two species, and no fish length element level–body-length relationship was observed, except for Hg. The average metal(loid) levels, irrespective of species, varied in the following ranges: Hg = 0.18–0.19, Cd = 0.07–0.10, Pb = 0.10–0.12, As = 0.59–0.69 μg g⁻¹ w.w. The concentrations remained below the maximum permissible limits (MPLs) for human consumption, except for Cd. The estimated intakes of Hg, Cd and Pb in both consumption scenarios were lower than the respective PTWI/PTMIs, as well as those of inorganic As, which were even lower than the BMDL₀₁. The non-carcinogenic risk (THQ) did not reveal any concerns, except for Hg. The lifetime health cancer risk (ILCR) suggested hazard exclusively from Cd, although for high-level fish consumers, even the ILCR of inorganic As was, in some cases, above the acceptable range. Continuous monitoring of metal(loid) levels in these fish is strongly recommended because the results demonstrate the occurrence of potential health risks, especially in high-level fish consumers, due to the presence of Hg and Cd.