Scientific Opinion on the safety of trivalent chromium as a nutrient added for nutritional purposes to foodstuffs for particular nutritional uses and foods intended for the general population (including food supplements)

Metals on the Menu-Analyzing the Presence, Importance, and Consequences

Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium, potassium, magnesium, calcium, iron, zinc, and copper are crucial for various physiological functions and must be consumed through the diet, others, like lead, mercury, and cadmium, are toxic even at low concentrations and pose serious health risks. This study comprehensively analyzes the presence, importance, and consequences of metals in the food chain. We explore the pathways through which metals enter the food supply, their distribution across different food types, and the associated health implications. By examining current regulatory standards for maximum allowable levels of various metals, we highlight the importance of ensuring food safety and protecting public health. Furthermore, this research underscores the need for continuous monitoring and management of metal content in food, especially as global agricultural and food production practices evolve. Our findings aim to inform dietary recommendations, food fortification strategies, and regulatory policies, ultimately contributing to safer and more nutritionally balanced diets.

Heavy Metal Concentrations of Beeswax (Apis mellifera L.) at Different Ages

Beeswax is a naturally occurring product that worker bees produce. Beeswax is used in a variety of industries and pharmaceuticals. Humans utilize it extensively in cosmetics, medicinal formulations, and food manufacturing. Beeswax is an essential component of advanced contemporary beekeeping. Beekeepers, in particular, utilize significant amounts of beeswax to make beeswax comb foundation. In its natural condition, beeswax is white, but it becomes yellow then dark in color when it comes into touch with honey and pollen. The ongoing use of wax comb in bee activities (such as brood rearing, storage honey and bee bread), combined with environmental factors such as heavy metal and pesticide residues, resulted in a black color. Because of heavy metals can accumulate in wax for decades, beeswax can be a helpful tool for gathering data on hazardous contaminants in the environment. Because of their lipid-based chemical composition, beeswax combs act as a sink for numerous ambient pollutants as well as poisons when in the hive. The current study aims to measure nine heavy metals and important elements, including iron (Fe), chromium (Cr), zinc (Zn), copper (Cu), nickel (Ni), manganese (Mn), lead (Pb), cadmium (Cd), and cobalt (Co) in beeswax collected in the Behaira governorate region of Egypt between 2018 and 2022. Sample collection was conducted each year in triplicate. The samples were analyzed using an atomic absorption spectrophotometer. The quantity of metals in beeswax at different ages differed significantly. Depending on the wax age, Fe has the highest concentration in the range of 2.068 to 5.041 ppm, while Cd has the lowest ratio at 0.024 to 0.054 ppm from the first to fifth years old of comb age. The findings showed that as beeswax combs aged, the concentration of heavy metals rose. According to the study, it should gradually recycle beeswax combs each year and also adding new foundations.

Pharmacokinetics of chromium-enriched yeast in rats following oral administration

Chromium (Cr) is required for carbohydrate, lipid, and protein metabolisms in humans and animals. Cr insufficiency is associated with diabetes and cardiovascular disease. Chromium-enriched yeast (CrY) is a widely used Cr dietary supplement, but its pharmacokinetics remains unavailable. CrY was orally administered to rats at a single dose of 1 mg Cr/kg, and plasma Cr concentration at different time points was measured by inductively coupled plasma mass spectrometry. Pharmacokinetics of CrY in rats was well fitted to a non-compartmental model. Plasma Cr concentration reached the maximum of 8.68 ± 2.87 ng/mL at 0.25 h, and gradually decreased to 4.05 ± 0.47 ng/mL at 24 h. CrY was rapidly absorbed into the blood and was slowly eliminated after the oral administration, which could lead to the accumulation of Cr in vivo.

Trace Elements and Heavy Metal Contents in West Algerian Natural Honey

Analysis of trace elements and heavy metals in honey is essential for honey quality and safety and also monitoring environmental pollution. This study aimed to evaluate the composition of thirty-seven honey samples of different botanical origins (14 multifloral and 23 unifloral) obtained from beekeepers located in the west region of Algeria. Inductively coupled plasma-mass spectrometry (ICP-MS) and atomic absorption spectroscopy (AAS) methods were used to determine the levels of 19 elements in honey (K, Na, Ca, Mg, Mn, Cu, Fe, Zn, V, Cr, Co, As, Ru, Rh, Cd, W, Pt, Au, and Pb). Ru, Rh, Pt and, Au were not detected in any of the tested honey samples. The most abundant minerals were K, Ca, Na, and Mg ranging within 153.00-989.00 mg/kg, 33.10-502.00 mg/kg, 13.30-281.00 mg/kg, and 20.80-162.00 mg/kg, respectively. Fe, Mn, Zn, and Cu were the most abundant heavy metals while Pb, V, Cr, W, Co, and Cd were the lowest ones (<1 mg/kg) in the honey samples surveyed. Several honey types, lavender, rosemary, mild white mustard, thyme, milk thistle, carob tree, orange tree, Euphorbia, Eucalyptus, camphor, jujube tree, sage, and harmal, were studied, and the statistical analysis was carried out using principal component analysis (PCA) and hierarchical cluster analysis (HCA) techniques to evaluate the data. The results showed that the analyses of mineral content were sufficient to determine the floral origin and their variability may be related to geochemical and geographical differences. On other hand, all elements detected were at levels below safe thresholds.

Safety and efficacy of a feed additive consisting of chromium propionate (KemTRACE™ Chromium) for all growing poultry species (Kemin Europa NV)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of chromium propionate (KemTRACE™ Chromium; KemTRACE-Cr) as zootechnical feed additive for all growing poultry species. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) Panel was assigned to this mandate. Based on two tolerance studies submitted, the Panel concluded that the additive is safe for chickens for fattening at the maximum recommended supplementation level of 0.4 mg Cr/kg feed from KemTRACE-Cr, but a margin of safety cannot be established; this conclusion can be extended to chickens reared for laying/breeding, but cannot be extrapolated to other growing poultry species. The FEEDAP Panel considered that the use of KemTRACE-Cr in animal nutrition at the proposed conditions of use is safe for the consumer. No concerns for users following any inhalation exposure during the handling of the additive are expected; the additive was shown to be corrosive to the eyes but not irritant to skin or a skin sensitiser. The use of KemTRACE-Cr in animal nutrition according to the proposed conditions of use will not significantly alter the concentration in the receiving environmental compartments of concern; therefore, no safety concern is expected for the environment. Based on three efficacy studies, the FEEDAP Panel concluded that KemTRACE-Cr has the potential to be efficacious as a zootechnical additive in chickens for fattening at the supplementation level of 0.4 mg Cr/kg feed; this conclusion could be extended to chickens reared for laying and chickens reared for breeding, and extrapolated to other poultry species for fattening and reared for laying/breeding.

Chromium Pollution in European Water, Sources, Health Risk, and Remediation Strategies: An Overview

Chromium is a potentially toxic metal occurring in water and groundwater as a result of natural and anthropogenic sources. Microbial interaction with mafic and ultramafic rocks together with geogenic processes release Cr (VI) in natural environment by chromite oxidation. Moreover, Cr (VI) pollution is largely related to several Cr (VI) industrial applications in the field of energy production, manufacturing of metals and chemicals, and subsequent waste and wastewater management. Chromium discharge in European Union (EU) waters is subjected to nationwide recommendations, which vary depending on the type of industry and receiving water body. Once in water, chromium mainly occurs in two oxidation states Cr (III) and Cr (VI) and related ion forms depending on pH values, redox potential, and presence of natural reducing agents. Public concerns with chromium are primarily related to hexavalent compounds owing to their toxic effects on humans, animals, plants, and microorganisms. Risks for human health range from skin irritation to DNA damages and cancer development, depending on dose, exposure level, and duration. Remediation strategies commonly used for Cr (VI) removal include physico-chemical and biological methods. This work critically presents their advantages and disadvantages, suggesting a site-specific and accurate evaluation for choosing the best available recovering technology.

Mobility of trace metals in serpentinite-derived soils of the Pollino Massif (Southern Italy): insights on bioavailability and toxicity

This paper deals with the evaluation of geo- and bioavailability of trace elements, including heavy metals, present in a typical serpentinite-derived soil of the Pollino Massif (Southern Italy). Precisely, the research was aimed to (1) assess processes and factors controlling the mobility of metals in the soil in order to identify the elements "potentially harmful" for the human health, (2) estimate possible metals accumulation in horticultural crops, and (3) evaluate phyto- and genotoxicity of Cr naturally present in soils and water. The studied profile has a homogeneous mineralogical composition consisting of metal-rich phases as prevailing minerals. The three-step sequential extraction was performed on soil samples from which four fractions (exchangeable, reducible, oxidizable, and residual) were obtained and analysed by ICP-MS. The lowest contents of metals are in the exchangeable and oxidizable fractions suggesting a metal contamination is unlikely for the studied soil. Conversely, the residual and reducible fractions are the more metal enriched fractions. Among heavy metals, mainly Pb and Cd and subordinately Ni, Cr, Cu, and Zn are associated with Fe- and Mn-oxi/hydroxides that, under acidic conditions, may release the adsorbed metals in circulating water. The high contents of heavy metals, including Cr and Ni, of analysed vegetables suggest a metal transfer from soil to plant. However, no significant effects on Vicia faba seeds were observed by in vivo phyto- and genotoxicity tests. Conversely in vitro genotoxicity tests, performed on HepG2 human cell line, showed that DNA damage and cytotoxic effect depending on Cr concentration may occur.

Safety and efficacy of Availa®Cr (chromium chelate of DL-methionine) as a feed additive for dairy cows

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Availa®Cr (active compound: chromium chelate of DL-methionine) as a feed additive for dairy cows. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) Panel was assigned to this mandate. The tolerance study did not show adverse effects with respect to body weight, milk yield, haematology and blood biochemistry up to the 10-fold overdose of chromium from Availa®Cr; however, owing to deficiencies in design and reporting of the study, it provided only supportive evidence on the safety of the additive. A safe level for dairy cows could be derived from a toxicological study with laboratory rodents. Taking all together, the FEEDAP Panel considers the maximum recommended use level (8 mg Cr from Availa®Cr/cow per day; about 0.4 mg Cr/kg complete feed) as safe. Chromium DL-Met shows a genotoxic activity in vitro that is not expressed in vivo after systemic exposure; although no data on genotoxicity at the site of contact are available, the Panel notes that chromium(III) is not carcinogenic and concludes that chromium DL-Met is unlikely to pose a carcinogenic risk at levels occurring in the diet. The use of Availa®Cr in feed of dairy cows up to the recommended supplementation level would not measurably increase consumer exposure to chromium(III), and therefore is safe for consumers. The additive poses a risk to users by inhalation, it is not an irritant to skin and eyes and should be considered a sensitiser. The use of the additive is not expected to pose a risk to the environment. Since only one study could be considered for the efficacy assessment, and three studies are required, the FEEDAP Panel cannot conclude on the efficacy of Availa®Cr for dairy cows.

Heavy metals determination in honey samples using inductively coupled plasma-optical emission spectrometry

BACKGROUND

Honey contains a complex mixture of carbohydrates and other minor substances. Elements are minor constituents of honey that may threaten the human health in excess concentrations. So, determining the metals in honey helps its quality control as a food product. The aim of this study was to determine the concentrations of some metals in Iranian honey.

METHODS

This study was performed in four regions of Ardabil, a province of Iran. Honey samples (n = 25) were digested in microwave oven by nitric acid and hydrogen peroxide, then analyzed using inductively coupled plasma- optic emission spectrophotometry (ICP-OES).

RESULTS

No significant differences were observed in cadmium, zinc, nickel, and chromium levels between regions (P > 0.05). Zinc was the most abundant metal in honey samples (1481.64 μg/kg). Some metals had higher concentrations in the East region because of existence more industries there. The highest mean of lead level was 935.48 μg/kg in the East and the lowest was 205.4 μg/kg in the South region. The concentrations of metals were compared with recommended limits for foods. Some of them were higher than standard levels (lead) and some were lower than those (cadmium).

CONCLUSIONS

Metals are released into the environment through their use in industrial processes and enter the food chain from uptake by plants from contaminated soil or water. Metals concentration in various places depends on many variables, leading to their different concentrations in honey. Some control measures like the quality control of food products, monitoring the soil in agricultural regions and limiting the use of fertilizers are recommended.

Assessments of chromium (and other metals) in vegetables and potential bio-accumulations in humans living in areas affected by tannery wastes

Chromium (Cr) commonly enters the food chain through uptake by vegetables. However, accurate prediction of plant uptake of Cr (and other metals) still remains a challenge. In this study, we evaluated 5 indices of availability for Cr (and other metals) to identify reliable predictors of metal transfer from soils to garlic, onion, bokchoy, radish and celery grown in soils impacted by tannery wastes. The potential bio-accumulation of Cr in humans was calculated from the Cr content of vegetable predicted by the best bio-availability index, amounts of vegetable consumed and recommended daily doses for Cr. Our results show that soil total Cr is the best predictor of Cr transfer from soils to onion (Cr in onion=8.51+0.005 Total Cr) while Cr extractable by Synthetic Precipitation Leaching Procedure at pH 5 correlates very well with Cr uptake by bokchoy (Cr bokchoy=5.86+7.32 SPLP-5 Cr) and garlic (Cr garlic=7.63+2.36 SPLP-5 Cr). The uptake of Cr by radish and celery could not be reliably estimated by any of the 5 indices of availability tested in this study. Potential bio-accumulation of Cr in humans (BA-Cr) increases from soils with low Cr (BA-Cr=11.5) to soil with high total Cr (BA-Cr=31.3). Due to numerous soil factors affecting the behavior of Cr in soils and the physiological differences among vegetables, we suggest that the prediction of the transfer of Cr (and other metals) from soils to plants should be specific to site, metal and vegetable. Potential bio-accumulation of Cr in humans can be derived from a transfer function of Cr from soils to plants and the human consumption of vegetables.