The trace metal levels in milk and dairy products consumed in middle Anatolia-Turkey

Evaluate the aluminum concentrations in whey milk samples of cows from different areas using deep eutectic solvent-based ultrasound-assisted dispersive liquid-liquid microextraction method

This study investigates the contamination of cow milk with aluminum (Al) and its potential health implications, particularly for children. Cow milk samples were collected from both nonexposed and exposed areas in Sindh, based on the source of livestock drinking water (fresh canals and groundwater). An environmental friendly deep eutectic solvent (DES) was used with ultrasonic-assisted dispersive liquid-liquid microextraction (UDLLμE) to enrich trace amounts of Al in whey milk and water samples. The enriched samples were then analyzed using inductively coupled plasma optical emission spectrometry. Certified reference materials were employed to validate the methodology, and the experimental results exhibited acceptable conformity. The DES-based dispersive liquid-liquid microextraction method was environmental friendly, devoid of acids and oxidizing agents, and used safe and inexpensive components for routine trace metal analysis in diverse samples. The resulting data revealed that Al in whey milk samples was observed in the range of 31-45 %, corresponding to (160-270) μg L-1 and (700-1035) μg L-1 in nonexposed and exposed whole cow milk samples, respectively. Additionally, it was observed that milk boiling in Al utensil for 10-20 min enhanced the Al levels from 3 to 8% of its total contents in milk samples.

Rapid and sensitive in situ detection of heavy metals in fish using enhanced Raman spectroscopy

Heavy metals have been widely applied in industry, agriculture, and other fields because of their outstanding physics and chemistry properties. They are non-degradable even at low concentrations, causing irreversible harm to the human and other organisms. Therefore, it is of great significance to develop high accuracy and sensitivity as well as stable techniques for their detection. Raman scattering spectroscopy and atomic absorption spectrophotometer (AAS) were used parallelly to detect heavy metal ions such as Hg, Cd, and Pb of different concentrations in fish samples. The concentration of the heavy metals is varied from 5 ppb to 5 ppm. Despite the satisfactory recoveries of AAS, their drawbacks are imperative for an alternative technique. In Raman scattering spectroscopy, the intensities and areas of the characteristic peaks are increased with increasing the concentration of the heavy metals. For Hg concentration ≥ 1 ppm, a slight shift is observed in the peak position. The obtained values of peak intensity and peak area are modeled according to Elvoich, Pseudo-first order, Pseudo-second order, and asymptotic1 exponential model. The best modeling was obtained using the Elovich model followed by the asymptotic1 exponential model. The introduced Raman spectroscopy-based approach for on-site detection of trace heavy metal pollution in fish samples is rapid, low-cost, and simple to implement, increasing its visibility in food safety and industrial applications.

Potentially toxic elements in soil-plant-water-animal continuum in a mining area from Northwestern Mexico: animal exposure pathways and health risks for children

Mining increases environmental concentrations of potentially toxic elements (PTEs) accumulating in organisms and spreading in the human food chain-their presence in milk is of great human health concern. Pathways were identified by which these elements reach raw milk from farms within a mining area in Northwestern Mexico; health risks for dairy cattle and children were also evaluated. Water from river and cattle waterers, as well as, soils showed that PTE concentrations generally below the Mexican and international limits; cattle forage concentrations were above the World Health Organization limits. Al, Mg, Mo, Ni and Zn were recorded in raw milk samples from the mining area, showing that Cd, Co, Cr, Cu, Pb and V are transferred from soil to plants but not accumulated in raw milk. Zn concentrations in raw milk exceeded the permissible limit; milk from farms without mining operations (comparison site) showed the presence of Al, Cr and Cu. In cattle tail hair, PTE did not correlate with raw milk concentrations. Metal accumulation in milk was higher through water consumption than that accumulated through forage consumption. Daily intakes (DI) of Al, Mg and Zn in cows could represent a risk for their health. The observed biotransference was higher than in other parts of Mexico, and the calculated DI and hazard quotients indicate no adverse health effects for children. However, the hazard Index values indicate that exposure to multiple PTE represents a risk for children. Management measures should be performed to control the cumulative risks to protect young children's health.

The concentration and prevalence of potentially toxic elements (PTEs) in cheese: a global systematic review and meta-analysis

The present study aimed to systematically review the concentration of different PTEs, including Arsenic (As), Mercury (Hg), Lead (Pb), and Cadmium (Cd) in cheese among some databases between 2000 and 2021 (from 57 included studies). Estimated concentrations of 160.78 (95% CI = 119.24-202.28), 15.68 (95% CI = 11.88-19.48), 16.94 (95% CI = 13.29-20.59), and 2.47 (95% CI = 1.70-3.23) µg/kg were calculated for As, Pb, Cd, and Hg, respectively. Most of the studies for PTEs are related to Pb, about 40% of the studies, compared to As, which has fewer studies. The results showed that As and Hg concentrations were lower than the Codex Alimentarius Commission standard limits. Nevertheless, Cd and Pb concentrations were higher than the standard limit values. Results showed that cheese making, the ripening period, fat content, and texture are influential factors in a high level of Pb and Cd in cheese samples.

Occurrence, Source and Dietary Exposure of Toxic and Essential Elements in the Indian Food Basket

In this study, representative urban and peri-urban Indian food baskets have been studied for the presence of toxic and essential elements. The concentration of target toxic and essential elements was used to estimate dietary intakes (EDIs) and health risks. Across all food matrices, toxic elements like Cd and Pb were dominant. The highest concentrations of the target elements were found in vegetables, with Cd, Pb, and Ni being beyond permissible limits of the Food and Agriculture Organization of the United Nations and the World Health organization (0.05 mg/kg, 0.1 mg/kg, and 1.5 mg/kg, respectively) in okra, spinach, and cauliflower. The sum of concentrations of the toxic elements (As, Ni, Hg, Cr, Cd, Pb) in vegetables had a range of 0.54-12.08 mg/kg, the highest sum was found in spinach (median 12.08 mg/kg), followed by okra (median 1.68 mg/kg). The EDI was observed for vegetables with a contribution as high as 92% for Cd. Dairy products were found with the highest loading for Ni with a dietary intake of 3.1 mg/kg/day for adults and twice as much for children. Carcinogenic risk for Ni was the highest and found above the threshold for all food categories, as was the case with As. Cumulative carcinogenic and non-carcinogenic risks were mostly contributed by milk and vegetables, in particular, spinach.

Heavy metal levels in milk and dairy products and health risk assessment: A systematic review of studies in China

Previous studies have indicated that heavy metal levels in milk vary partly depending on environmental metal concentrations. Given the increasing consumption of milk in China, it is essential to pay attention to milk safety. We performed a systematic review of relevant published studies to evaluate the heavy metal levels in milk and dairy products and the associated health risks, discuss environmental sources of heavy metals, and propose future research directions. A literature search was implemented in the Web of Science Core Collection and PubMed using multiple keywords such as "metal," "milk," "dairy products," and "China". A total of 16 published studies that analyzed metal levels in milk and dairy products in 20 provincial administrative regions were included. Most studies detected toxic heavy metals in milk and dairy products samples, including mercury, lead, cadmium, chromium, and arsenic. The lead concentration in milk from these studies did not exceed the Chinese standard for milk. However, three studies detected relatively high lead levels in both commercial and raw milk, exceeding the European Commission standard. The polluted environment surrounding the farm, feed, and packaging materials are likely sources of metals in milk and dairy products. The hazard index for the 11 analyzed metal elements in milk and dairy products was lower than 1, indicating negligible non-carcinogenic health risks from exposure to these metals. Children are at a higher risk than adults. This review illustrates that research in this field is limited to China. More research should be conducted in the future, such as evaluating the contribution of each environmental source of metal in milk and dairy products.

Mutagens in raw ewe milk in Orava region, northern Slovakia: metals

The aim of this work was to determine the concentrations of selected mutagenic elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Se) in raw ewe milk from undisturbed environment in Orava region, northern Slovakia. There are possible sources of some of the analyzed metals which may be distributed from the metallurgical plants located in the Ostrava region, Czech Republic, and Katowice, Poland. In total, forty milk samples were analyzed in June and August using an inductively coupled plasma optical emission spectrometry. The differences in elements concentrations between the seasonal periods were not significant except of iron (p < 0.0001). The concentrations of most of the metals in ewe milk were low and under the permissible or recommended limits. However, arsenic and selenium concentrations were elevated and could pose a risk of the mutagenic effect, particularly in children. The frequency of element occurrence in June was as follows: Se > Fe > As > Cu > Mn > Ni > Co > Pb > Cr > Cd, and in August: Se > Fe = As > Cu > Mn > Pb > Co > Ni > Cr > Cd. The correlation analysis revealed very strong positive correlation between Cu:Pb (p < 0.05), very strong negative correlation between Fe:Se (p < 0.05). The strong correlations were also found between other elements. The present study showed that milk produced in the relatively undisturbed environment might contain various mutagenic elements. The relationships between the elements might result in the additive or synergistic effects of elements and increase the risk of their mutagenic effects even in low concentrations. Therefore, attention must be paid to the monitoring of metals in the areas where food sources destined especially for child nutrition are produced.

Concentrations of Essential Trace and Toxic Elements Associated with Production and Manufacturing Processes in Galician Cheese

The objective of this study was to determine the trace element composition and the toxic metal residues in Galician cow’s milk cheese produced in different systems (artisan, industrial, and organic). Fourteen elements (As, Cd, Co, Cr, Cu, Fe, Hg, I, Mn, Mo, Ni, Pb, Se, and Zn) were determined in 58 representative samples of Galician cheeses by inductively coupled plasma mass spectrometry. The toxic elements were present at low concentrations, similar to those reported for other unpolluted geographical areas. The essential elements were also within the normal range in cheeses. There were no statistically significant differences between smoked and unsmoked cheeses for any of the elements. Chemometric analyses (principal component analysis and cluster analysis) revealed that the industrial cheeses produced in Galicia using the milk from intensive dairy farms were different, in terms of elemental content, from artisan and organic cheeses, in which the elemental contents were similar.

Risk assessment of potentially toxic trace elements via consumption of dairy products sold in the city of Yerevan, Armenia

The study aimed to investigate the potentially toxic trace elements (PTEs) Pb, Cd, Hg, Mo, and Cu in dairy products sold in Yerevan's markets and to assess the related exposure and possible health risks among the adult population residing in the capital city of Armenia, Yerevan. The PTEs contents were determined in widely consumed dairy products (pasteurized milk, sour cream, matsoun and cheese from cow milk) using graphite furnace atomic absorption spectrometry. PTE contents were in the range of 7.90E-04 (Pb in pasteurized milk) to 6.75E-01 (Cu in cheese) mg/kg. Food consumption was assessed by the 24-h dietary recall method. The PTE daily intakes and margin of exposure (MOE) were calculated by the deterministic approach. The results indicated potential health concerns for the contribution of dairy products to the overall dietary intake of Pb and Cd. MOEs of Pb and Cd (8.71 and 8.80, respectively) estimated for high consumers of cheese (90 g/day and more) were lower than 10. The pilot data set provides the first comprehensive appraisal on the dairy products contamination by PTEs in the Caucasus region. The results point out further attention to sources of Pb and Cd in Armenian dairy products, including environment and farm characteristics.

A Comprehensive Review on Selenium and Its Effects on Human Health and Distribution in Middle Eastern Countries

Selenium (Se) is an important microelement with numerous positive effects on human health and diseases. It is important to specify that the status and consumption of Se are for a specific community as the levels of Se are extremely unpredictable between different populations and regions. Our existing paper was based on the impacts of Se on human health and disease along with data on the Se levels in Middle Eastern countries. Overall, the findings of this comprehensive review show that the consumption and levels of Se are inadequate in Middle Eastern nations. Such findings, together with the growing awareness of the importance of Se to general health, require further work primarily on creating an acceptable range of blood Se concentration or other measures to determine optimal Se consumption and, consequently, to guarantee adequate Se supplementation in populations at high risk of low Se intake.

Determination of Lead Level in Pasteurized Milk and Dairy Products Consumed In Tehran and Evaluation of Associated Health Risk

Background: Milk and dairy products are the main sources of essential nutrients particularly for children. However, milk and dairy products can be contaminated with chemical hazards and contaminants which pose serious health risks for consumers. These toxic compounds are entered into the food chain through contaminated soil, water, and air and their presence even at low levels would result in metabolic disorders. Objectives: The aim of this study was to determine the level of lead in pasteurized milk and different dairy products in high-consumed brands in Tehran. Methods: A total of 38 samples (18 pasteurized milk and 20 dairy products from the most-consumed brands) were analyzed using graphite furnace atomic absorption spectroscopy for quantification of lead level. Hazard quotient (HQ) and carcinogenic risk (CR) were used to assess health risk and carcinogenic risk. Results: The results showed that the levels of lead in all pasteurized milk samples and dairy products were below the allowable limit. HQ was less than 1 in all samples and CR was in the range of 10-8 to 10-7 and both were at acceptable levels. Conclusions: It can be concluded that there was no risk of carcinogenicity in pasteurized milk samples and dairy products for children and adults. However, due to the higher consumption of milk by children and their greater susceptibility, the level of heavy metals should be monitored by health agencies.

Dietary risk of milk contaminated with lead and cadmium in areas near mining-metallurgical industries in the Central Andes of Peru

The mining-metallurgical industry in the central Andes of Peru is a source of lead (Pb) and cadmium (Cd) contamination in milk, and there are no studies on the impact of their ingestion. Using flame atomic absorption spectrometry, we quantified the concentration of these metals in raw milk produced in agroecological zones near these industries, and estimated the exposure and dietary risk in people aged 2-85 yr with minimum, average and maximum daily milk intake. In 2018, 40 raw milk samples were collected from 20 cows at two times of the year. The mean Pb and Cd concentrations were 577 ± 18.2 and 18.35 ± 5.4 μg/kg, all samples exceeded the maximum limits (ML). Children aged 2-5 and 6-15 yr, with average milk consumption, had Pb weekly intakes (WI) of 2019 and 2423 μg, exceeding the risk value; values for Cd 64 and 77 μg were below the risk values. In those older than 20 years the WI for both metals are below the risk values. The Dietary Risk Coefficient (DRC) to Pb in children younger than 8 years was >3 due to higher milk consumption in relation to body weight; for children aged 9-19 years it was 1.7 and 2.9, being <1 for those older than 20 yr. Cd RDCs were <1 at all ages, with the exception of 2-year-olds in the high milk consumption scenario (RDC > 1). There was notable evidence of Pb and Cd exposure risk from consumption of milk produced near mining-metallurgical activities, predominantly for children under 19-year-olds. In Peru there are no regulations for Pb and Cd in fresh milk and milk products, we recommended that ML for heavy metals in food be established.

Toxic element profile of ice cream in Bangladesh: a health risk assessment study

Ice cream is a popular frozen dairy product and a possible source of dietary minerals. However, ice cream may also contain toxic metals, which may cause several health implications. The current study aimed to determine the content of toxic elements in ice cream samples using inductively coupled plasma-optical emission spectrometry (ICP-OES) and to assess the health risks of consumers based on target cancer risk (TCR), target hazard quotient (THQ), and hazardous index (HI). The determined concentration (median, range) of all studied elements had shown a descending order of Al (9.36, 5.37-14.26) > Zn (5.94, 1.95-10.22) > Cu (1.73, 1.02-3.77) > Ni (0.95, 0.67-1.80) > Fe (0.79, 0.10-1.64) > Cr (0.43, 0.28-0.73) > Mn (0.42, 0.11-1.03) > Pb (0.34, 0.09-0.79) > Cd (0.08, 0.04-0.14) mg/kg (fresh weight). The values of THQ and HI (except 16% for children) were lower than the maximum threshold risk limit (TRL = 1.0), indicating no potential non-carcinogenic health effects might occur. Similarly, the TCR of Cr and Pb for both adults and children was within the permissible limit of 10^-4-10^-6, which suggested that the consumer would not experience potential lifetime carcinogenic health risks. However, the overall analyses revealed that the consumption of ice cream is almost safe for people, but the combined impact of all metals (HI) in some samples is a matter of health concern. Henceforth, regular monitoring of toxic metals in ice creams should be done to assure food safety and hygiene.

Heavy metals levels in raw cow milk and health risk assessment across the globe: A systematic review

This systematic review presents the potential toxicity of heavy metals such as lead (Pb), mercury (Hg), cadmium (Cd), iron (Fe), nickel (Ni), aluminum (Al), and copper (Cu) in raw cow milk, focusing on their contamination sources and on the assessment of the related human health risk. Multiple keywords such as "raw cow milk, heavy metals, and human health" were used to search in related databases. A total of 60 original articles published since 2010 reporting the levels of these metals in raw cow's milk across the world were reviewed. Data showed that the highest levels of Ni (833 mg/L), Pb (60 mg/L), Cu (36 mg/L) were noticed in raw cow milk collected in area consists of granites and granite gneisses in India, while the highest level of Cd (12 mg/L) was reported in barite mining area in India. Fe values in raw cow milk samples were above the WHO maximum limit (0.37 mg/L) with highest values (37.02 mg/L) recorded in India. The highest Al level was (22.50 mg/L) reported for raw cow's milk collected close to food producing plants region in Turkey. The Target Hazard Quotients (THQ) values of Hg were below 1 suggesting that milk consumers are not at a non-carcinogenic risk except in Faisalabad province (Pakistan) where THQ values = 7.7. For the other heavy metals, the THQ values were >1 for Pb (10 regions out of 70), for Cd (6 regions out of 59), for Ni (3 out of 29), and for Cu (3 out of 54). Exposure to heavy metals is positively associated with diseases developments. Moreover, data actualization and continuous monitoring are necessary and recommended to evaluate heavy metals effects in future studies.

Lead and cadmium biosorption from milk by Lactobacillus acidophilus ATCC 4356

The food and water contamination with heavy metals is increasing due to the environmental pollutions. Lead and cadmium are the toxic heavy metals for humans that can be found in air, soil, water, and even food. Lactic acid bacteria have the ability to remove and diminish the level of heavy metals. In this study, Lactobacillus acidophilus was used to remove lead and cadmium in milk and the capability of this valuable bacterium in biosorption of these metals low concentrations (µg/L or ppb) in milk was evaluated. First, the variables on lead and cadmium removal by this bacterium have been studied by Plackett-Burman design. Then, the bioremoval process was optimized and the three main factors, the bacterium concentration, contact time, and the initial heavy metal concentration were chosen by using a central composite design. The optimum lead and cadmium bioremoval yield of 80% and 75% were observed, respectively, at 1 × 1012 CFU of L. acidophilus in milk at the 4th day and the initial ion concentration of 100 µg/L. The 3D plots analysis showed the interaction effects on metal biosorption. This study showed that L. acidophilus is a natural effective biosorbent for lead and cadmium removal from milk.

The Biosorption Capacity of Saccharomyces Cerevisiae for Cadmium in Milk

This study aimed to evaluate the capacity of Saccharomyces cerevisiae for Cadmium absorption in milk. Nowadays, one of the most serious problems of the industrialized world is heavy metal pollution. Applying microorganisms as novel biotechnology is very useful, especially in foodstuffs. Among the biosorbents used for heavy metal removal, Saccharomyces cerevisiae has received increasing attention due to its popularity in the food industry. In this regard, the effects of some important factors such as the initial metal concentration, biomass concentration and contact time on the biosorption capacity of Saccharomyces cerevisiae were studied. The biosorption was analyzed by the inductively coupled plasma mass spectrometer (ICP-MS). The maximum cadmium (Cd) removal (70%) was at 80 μg/L of Cd concentration in milk samples containing 30 × 108 CFU Saccharomyces cerevisiae at the end of storage time (the 4th day). There were no significant differences in the sensory and physicochemical properties (pH, acidity and density) of milk samples during storage (p < 0.05). The isotherm studies were followed by two popular models, Langmuir and Freundlich, and the results showed a better fit to the Langmuir isotherm. Altogether, the results of this study demonstrate that the approach of using this valuable yeast could be applied for food detoxification and producing healthier foodstuffs.

Extraction of Cu, Fe, Mn, and Ni from Margarine Samples Using Extraction Induced by Emulsion Breaking Procedure Prior to Graphite Furnace Atomic Absorption Spectrometry and Comparison of Results to Provisional Tolerable Daily Intake Values

BACKGROUND

The emulsion induced by emulsion breaking (EIEB) procedure was previously reported for the extraction of copper, iron, manganese, and nickel from liquid oil samples such as vegetable oil.

OBJECTIVE

To optimize the EIEB procedure for determination of copper, iron, manganese, and nickel in solid oil (margarine) samples by Graphite Furnace Atomic Absorption Spectrometry (GFAAS).

METHODS

The extraction procedure uses a surfactant in nitric acid to form an emulsion followed by heating to break the emulsion. Optimization included variation of the test portion size, the type and concentration of the surfactant, the concentration of nitric acid in the aqueous solution, the emulsion agitation time, heating temperature, and the time required to break the emulsion.

RESULTS

Mean element concentrations of 11 margarine samples were in the following ranges: Cu 0.031-0.131 µg/g, Fe 5.7-24.9 µg/g, Mn 0.542-1.11 µg/g, and Ni 0.108-0.134 µg/g. Under the optimized extraction conditions, the detection limits (µg/kg) were 4.8, 13, 1.5, and 23 for Cu, Fe, Mn, and Ni, respectively. The accuracy of the extraction procedure was determined by comparison to commonly used microwave digestion procedure. The EIEB results were not statistically different from the microwave digestion results when analyzed by GFAAS as determined by the statistical tests.

CONCLUSIONS

The EIEB procedure was shown to be equivalent to the commonly used microwave digestion procedure for extraction of analytes from margarine samples.

HIGHLIGHTS

The optimized EIEB extraction procedure is simple, rapid, low cost, and environmentally friendly. It has improved detection limits and allows calibration with aqueous standards.

Concentrations of toxic metals and essential elements in raw cow milk from areas with potentially undisturbed and highly disturbed environment in Slovakia

Dietary composition and husbandry practices largely determine the essential trace element status and the toxic metal exposure of livestock and consequently their concentrations in animal products. The main objective of this study was to determine the real contamination of selected areas of Slovakia compared with existing Environmental regionalization of the Slovak Republic (SR) created by the Ministry of the Environment SR. Another aim of this study was to determine the content of essential and toxic metals in feed and milk of dairy cows on selected farms in Slovakia referred to the suitability of the use of milk from these areas to other food processing. This article deals with the analysis of the content of selected elements in feed and milk of dairy cows in the area of Novoť (Northern Slovakia; area with undisturbed environment) and Čečejovce (Eastern Slovakia; highly disturbed environment). Eleven elements have been analyzed (essential elements: calcium, zinc, magnesium, selenium, iron, copper; toxic elements: arsenic, cadmium, mercury, lead, nickel). Samples of feed and milk were collected five times during the spring season and five times during the autumn season in 2016. Analysis of samples was performed in Eurofins Bel/Novamann (Nové Zámky, Slovak Republic). Analyses were performed by atomic absorption spectroscopy and atomic emission spectrometry. The obtained values of the individual elements in the feed and milk were evaluated by Student's t test. Significantly higher contents of essential elements Ca, Zn, Fe, Mg, and Cu were found in the feed of dairy cows in Čečejovce (P < 0.001). Significantly higher (P < 0.001) As and Ni content in feed in Čečejovce in autumn season was also recorded. However, the content of these elements in feed did not affect their milk content. The content of Ca, Zn, and Mg in milk was significantly (P < 0.001) higher in Novoť in both investigated seasons. Some essential elements and toxic elements in feed and milk were below the LOQ (limit of quantification). Reduced content of Ca and Zn in milk in both farms compared with optimal limits, decreased Ca and Mg content in feed in Novoť, and a significant increase of Ca and Mg in feed in Čečejovce in autumn season were found. It can be concluded, due to the low content of toxic elements on these farms, that the use of milk of dairy cows from these areas for direct use or for dairy product processing is appropriate and poses no health risk to the consumers.

Essential and xenobiotic elements in cottage cheese from the Slovak market with a consumer risk assessment

The examination of various elements in the milk products is very important in the food sector in respect of food quality and safety. The aim of this study was to determine the concentrations of calcium (Ca), cobalt (Co), cadmium (Cd), copper (Cu), chromium (Cr), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), sodium (Na), nickel (Ni), phosphorus (P), lead (Pb) and zinc (Zn) in white cottage cheese or cottage cheese supplemented with various additives (white, lacto-free, chive, tzatziki, mustard + onion, chili, active protein) available on the market of Slovakia. All essential elements were within the reference range. Cottage cheese enriched with tzatziki showed higher amount of Cu, Fe, K, and Zn. Mustard + onion cheese contained high values of Ca, Co, Mg, and Ni. In white cottage cheese high amount of Cr, Mn, and P was measured. The content of xenobiotic metals was below permitted limit. The contribution to PTWI (Provisional tolerable weekly intake) suggested very low dietary exposure to heavy metals as Cd, Hg, and Pb as well as other metals (Cu, Ni, and Zn) in cottage cheese. Numerous correlations between concentrations were observed. MOE (Margin of Exposure) evaluation denoted that average consumption of cottage cheese does not pose any high cardiovascular and nephrotoxicity threat.

Evaluation of Heavy Metal Content in Feed, Litter, Meat, Meat Products, Liver, and Table Eggs of Chickens

We assessed the concentrations of Fe, Cu, Zn, Mn, Se, Co, Cr, Pb, Cd, and Ni in chicken meat and meat products, feed, and litter, as well as laying hens' eggs, feed and litter to monitor the quality of products on the market and their safety for human consumption as judged by recommended daily allowance (RDA) and tolerable upper levels. Samples were chosen as the most popular poultry products in Saudi Arabia. A total of 45 broiler samples of frozen or fresh meat, liver, burger, or frankfurter were chosen from the same brand. Additionally, 60 table eggs from four commercial brands were collected, and the edible parts of these were used to determine levels of minerals and toxic elements. Furthermore, 30 feed and litter samples were collected from the starter, grower, and layer diets of broilers and laying hens. The results indicated that there were significant levels of most of the trace elements and heavy metals in the different meat sources. Furthermore, the liver contained the highest levels of elements, except for Cr, Co, and Ni. The highest Cr level was detected in the fresh meat, followed by frozen meat. Trace elements (Mn and Co) and heavy metals (Ni and Pb) were not detected in either the frozen or the fresh meat. The chicken burger and the frankfurter exhibited similar trace-element and heavy-metal contents, except for Zn and Mn, as the frankfurter showed higher concentrations than the burger. Differences in most of the trace and toxic elements among the different sources of eggs were not found to be significant, except for Zn. Differences between the broiler meat and table eggs were only substantial for Fe and Zn. Fe was significantly higher in meat than in eggs, and the opposite trend was found for Zn. The liver contained higher heavy metals than the eggs, except for Cr. In addition, the burger had higher concentrations of essential (Cu and Co) and heavy metals (Pb and Ni) than the eggs but had lower levels of Zn and Cr. The frankfurter exhibited significantly higher levels of Fe, Cu, Mn, Co, Pb, and Ni than the eggs but lower levels of Zn and Cr. To summarize, Cd, Pb, As, and Se were not detected in the broiler meat or eggs, indicating no risks from these toxic elements. Conversely, the liver exhibited the highest content of heavy metals, except for Cr, indicating that the intake of Pb and Cd was above the recommended daily allowance (RDA) for adults. The meat products exhibited higher Pb, Cd, and Ni levels than the broiler meat and the table eggs, suggesting that they posed a health threat to humans, and the intake of Pb in the meat products was higher than the RDA. Thus, chicken meat and table eggs, which are primary protein sources, are safe sources of human nutrition, while liver and meat products may present potential health hazards through the food chain.

A systematic review and meta-analysis of lead and cadmium concentrations in cow milk in Iran and human health risk assessment

The aim of the current research was to systematically review and summarize the studies that evaluated the concentration of lead (Pb) and cadmium (Cd) in cow milk in different regions of Iran and to perform a meta-analysis of the findings. Moreover, the non-carcinogenic and carcinogenic risks of Pb and Cd through milk consumption in adult and child consumers were assessed. As a result of a systematic search in the international and national databases between January 2008 and October 2018, 17 reports involving 1874 samples were incorporated in our study for meta-analysis. The pooled concentrations of Pb and Cd were estimated to be 13.95 μg mL^-1 (95% CI 9.72-18.11 μg mL^-1) and 3.55 μg mL^-1 (95% CI - 2.38-9.48 μg mL^-1), respectively, which were lower than the WHO/FAO and national standard limits. The estimated weekly intake (EWI) of Pb and Cd through consuming milk was 16.65 and 7 μg day^-1 for adults of 70 kg and 45 and 34 μg day^-1 for children of 26 kg, respectively, which was well below the risk values set by Joint FAO/WHO Expert Committee on Food Additives (JECFA). The maximum target hazard quotient values (THQs) of Pb and Cd were 5.55E-5 and 5.55E-5 for adults and 5.55E-5 and 5.55E-5 for children, respectively, which were lower than 1 value, suggesting that Iranian consumers are not exposed to non-carcinogenic risk through consuming milk. Moreover, the incremental lifetime cancer risk (ILCR) of Pb estimated to be 2.96E-04 in adults and 1.0E-03 in children, indicating that consumers in Iran are at threshold carcinogenic risk of Pb through consuming milk (ILCR > 10^-4). Therefore, planning and policy making for the sustainable reduction of these toxic metals in milk, particularly in industrial regions of Iran, are crucial.

Determination of some element levels in various kinds of cow's milk processed in different ways

This study aimed to measure zinc (Zn), selenium (Se), copper (Cu), iron (Fe), chromium (Cr), nickel (Ni), lead (Pb), cadmium (Cd), arsenic (As), and aluminum (Al) in whole, semi-skimmed, skimmed, organic, fruit-flavored (strawberry, banana, and cocoa), pasteurized, and raw cows' milk. The samples were collected from sterilized and pasteurized milk processed in different ways in Ankara; the milk was kept in refrigerated raw milk storage tanks on dairy farms. Ninety samples were collected, and there were ten samples in each group. Analyses were performed using inductively coupled plasma-mass spectrometry. Lead and Cd were not found in any samples, while Zn was observed in all samples. The element with the highest frequency of occurrence was Zn, followed by Cr = As> Al > Se > Fe > Ni > Cu > Pb = Cd, in decreasing order. The lowest concentration among the essential elements was seen in Cu. Aluminum and As were found in 85% and 94.45% of the samples, respectively. However, the present concentrations were below the level of a probable negative effect. It was found that the concentrations of elements in milk showed statistically significant differences, depending on the milk type. It is recommended that low-quality materials not be used in the preparation of milk; the element concentrations in milk and the feed and water consumed by animals should be controlled regularly, and the animals should not be pastured near industrial and traffic sites to protect public health.

Determination of trace elements, heavy metals, and antimony in polyethylene terephthalate-bottled local raw cow milk of Iğdır region in Turkey

The presence of several trace elements, heavy metals, and antimony in polyethylene terephthalate-bottled local raw cow milk samples of Iğdır region in Turkey was investigated. The milk samples were analyzed by inductively coupled plasma mass spectrometry after microwave-assisted digestion. Milk samples were categorized into three groups according to the element level intensity in the sample. While 70% of samples showed 2.5 times the maximum Turkish and European permissible level of lead, the lowest lead-contaminated sample exhibited 1.25 times this level. All the examined samples exceeded the maximum permissible limit administrated for arsenic and 35% of samples exhibited 5 times this limit. Results showed 40% of samples contain an antimony level higher than the Turkish maximum allowable concentration. The high antimony content of raw milk samples may be related to the release of antimony from the PET (polyethylene terephthalate) bottles. This study showed high contamination levels of the most toxic trace elements, i.e., lead and arsenic in milk and possible antimony contamination from PET bottles which may cause many health hazards for the consumers.

Some toxic metals (Al, As, Mo, Hg) from cow's milk raised in a possibly contaminated area by different sources

Milk can be considered as an indicator of the degree of environmental contamination of the place where it is produced and this is especially important when assessing its content in toxic metals. Therefore, 36 bovine milk samples from 7 farms with a semi-extensive grazing system were analysed, located in Asturias (Spain), in an area with high probability of being highly contaminated due to a mining zone, with important industrial activity and near high-density highway traffic. The samples were lyophilised to achieve total dehydration, further analysed using inductively coupled plasma mass spectrometry (ICP-MS). The metals titrated were aluminium (Al), arsenic (As), molybdenum (Mo) and mercury (Hg) in the lyophilised samples and subsequently extrapolated their values to whole milk. All samples analysed showed levels of Al and Mo above the limit of detection, with mean values of Al of 140.89 ± 157.07 in liquid milk and 1065.76 ± 1073.45 in lyophilised milk and Mo of 20.72 ± 14.61 μg/kg and 152.26 ± 96.82 μg/kg in whole and lyophilised milk. Only As was detected in four samples with mean values of 18.45 ± 6.89 and 166.45 ± 42.30 μg/kg in liquid and lyophilised milk, respectively, and no Hg was found in any of them. In no case do the values found indicate a significant hazard to the population and are in agreement with those found in other investigations. Although the various anthropogenic activities of the area (industrial, mining, traffic density) could, a priori, indicate a possibly contaminated area.

Determination of the content of Pb, Cd, Cu, Zn in dairy products from various regions of Poland

The toxicity of heavy metals and their capacity for accumulation in the human organism make it necessary to conduct monitoring of their concentration in food. The objective of the study was to determine the content of lead, cadmium, copper and zinc in milk and dairy products from various regions of Poland: the Lublin Region, Podlasie, Podkarpacie, and Silesia. The study showed the presence of the analysed heavy metals in most of the products. The content of lead was related to the level of industrialisation of a region. Higher levels of Pb were found in products from Silesia than in those from the other regions. The study revealed the presence of cadmium in 50% of the samples. Its content varied in range from 0.0067 to 0.0058 mg/kg. The levels of Cu and Zn concentration in the analysed products were within broad ranges, from 0.0015 to 4.94 mg/kg and from 0.01 to 56.44 mg/kg, respectively. In the case of all analysed elements an increase in their concentration was noted in cheese spreads and cottage cheeses. No relationship was found between the content of heavy metals in the analysed products, and the region of their origin.

Contamination of foods with arsenic and mercury in Iran: a comprehensive review

Human and animals are exposed to heavy metals such as arsenic (As) and mercury (Hg) through atmospheric depositions, industrial effluents, chemical pesticides and fertilizers, erosion of geological beds, and mining wastes which can result in the contamination of food chains. The aim of the current study was to review the available papers reporting contamination levels of As and Hg in commonly consumed foods in Iran. A descriptive search was carried out with specific keywords and entry criteria in databases of Science-Direct, PubMed, Scopus, Google Scholar, and Scientific Iranian Database (SID) published from January 2000 to July 2018. All articles were assessed by two reviewers, and final decision was made through discussions or a third reviewer arbitration. The articles were categorized based on the type of food groups including rice, fruit, vegetable, fish, seafood, drinking water, tea, and miscellanies. Of 221 identified articles on As and Hg contaminations in foods, 92 articles were selected using defined criteria. Published articles were reviewed to report contamination (mean and rate) of each food group in Iran. Results showed that rice and fish included the highest contamination rates of As and Hg, respectively. In general, As and Hg contents in Iranian foods cause serious health concerns due to the consumption quantities of the main foods. Further risk-based surveillance studies must be carried out to decrease exposure to As and Hg from dietary and non-dietary sources.

Heavy Metal Contamination of Milk and Milk Products Consumed in Tabriz

Background:

In this study, lead (Pb), cadmium (Cd), copper (Cu), Iron (Fe) and arsenic (As) contents in milk and different dairy product samples from in Iran (Tabriz) were measured.

Methods:

Samples of 10 brands of pasteurized milk, yoghurt, traditional and industrial kashk were selected and quantitative analysis for heavy metals were performed by a Varian AA240fs atomic absorption spectrometer with a Graphite Furnace (GTA 120).

Results:

The obtained ranges of mean heavy metals are given in the following: in milk 6.066-10.83, 2.343-6.070, 141.73-241.23, 2764.3-3151.3, 3.246-7.536ppb, in yoghurt 5.543-19.341, 3.143-8.830, 276.17-423.53, 2412.4-4115.7, 6.650-10.84, in industrial kashk 2.163-19.621, 1.541-13.45, 115.87- 565.40, 2588.4-5014.3, 4.346-20.351ppb, and in traditional kashk 7.972-32.723, 5.233-9.966, 416.42- 923.62, 4491.4-6402.3, 7.661-28.413 ppb, respectively.

Conclusion:

All the samples were below the internationally recognized permissible limits and did not pose any health risk to the consumption of milk and dairy products in Tabriz.

Selenium and Health: An Update on the Situation in the Middle East and North Africa

Selenium (Se) is an important trace element that should be present in the diet of all age groups to provide an adequate intake. Se is incorporated in 25 known selenoproteins, which mediate the biological effects of Se including, immune response regulation, maintenance of thyroid function, antioxidant defense, and anti-inflammatory actions. A balanced intake of Se is critical to achieve health benefits because depending on its status, Se has been found to play physiological roles or contribute to the pathophysiology of various diseases including, neurodegenerative diseases, diabetes, cancer, and cardiovascular disorders. Se status and intake are very important to be known for a specific population as the levels of Se are highly variable among different populations and regions. In the Middle East and North African (MENA) region, very little is known about the status of Se. Studies available show that Se status is widely variable with some countries being deficient, some over sufficient, and some sufficient. This variability was apparent even within the same country between regions. In this review, we summarized the key roles of Se in health and disease and discussed the available data on Se status and intake among countries of the MENA region.

Compositional and textural properties of goat’s milk cheese prepared using dahi (yogurt) as the starter culture

Abstract This study aimed to develop goat’s milk cheese to conserve the major milk constituents. Household dahi (yoghurt) is an inexpensive source of starter cultures that contains several types of microorganism of which most are thermophilic in nature and can be used in the production of goat’s milk cheese. Different concentrations of dahi (0.5%, 1.0%, 1.5%, 2.0% and 2.5%) were used to prepare the cheeses following the standard procedure for cheese manufacturing. The cheeses were analysed for their physicochemical, textural and organoleptic parameters. The highest yield was recorded for T1.0% (17.33%) and the lowest for T2.5% (15.58%). Significant (p < 0.05) differences were found for the pH, acidity and moisture content of the different goat’s milk cheese samples. The moisture content was highest in T0.5% (59.30) and lowest in T2.5% (52.20). The texture profile was significant (p < 0.05) for firmness, adhesiveness, gumminess and chewiness between the treatments. The sensory scores indicated that T1.0% was preferred by the panellists, followed by T1.5% and then the other treatments. It was concluded that goat’s milk cheese could be prepared with good quality characteristics using 1% dahi as the starter culture.

Lead and cadmium levels in raw bovine milk and dietary risk assessment in areas near petroleum extraction industries

Oil fields are a source of heavy metal pollution, but few studies have evaluated its impact on the intake of these contaminants through milk, an important food especially for children. From February 2015 to 2016, 118 samples of raw cow's milk, 14 of fodder and 8 of water in Southwest Iran were collected from farms close to oil fields or related industries. Lead (Pb) and cadmium (Cd) levels were evaluated by graphite furnace atomic absorption spectrometry. Mean±SE in milk and fodder were 47.0±3.9 and 54.0±6.9μg/kg for Pb, and 4.7±1.0 and 3.5±1.3μg/kg for Cd. No Pb or Cd was detected in water. Most milk samples (82.2%) for Pb were above the permissible limits (20μg/kg). Exposure to Pb and Cd from milk consumption was calculated in two scenarios: mean and maximum exposure for the age range of 2-90years. The intake of an average Iranian adult (25years, 60kg b. w., 0.14kg milk/day) would be 6.6μg Pb and 0.66μg Cd/day (WI of 46.2 and 4.6μg, respectively), well below the risk values proposed by some international organizations, even in the maximum exposure scenario. However, Pb exposure for infants and toddlers may be closer to the risk values, since milk and milk products could be the main contributor to Cd and Pb, and small children consume 2-3 times more food than adults relative to their body weight. The risk of Pb and Cd exposure through milk close to oil fields should be considered and a monitoring plan for these contaminants is strongly recommended.

Minerals and Heavy Metals in the Whole Raw Milk of Dairy Cows from Different Management Systems and Countries of Origin: A Meta-Analytical Study

The objective of this meta-analytical study was to investigate selected macrominerals, microminerals, and toxic heavy metals in the bovine whole-raw-milk (WRM) samples of published data. An analytical data set was constructed from 72 different studies from 37 countries with two types of production systems: a conventional production system (CPS) and an organic production system (OPS) compared with commercially available or retail-store-available milk (COM). Results of the meta-analytical study showed differences in the concentrations of macrominerals. Concentrations of Ca, Mg, K, and P were greater in the CPS samples, whereas Na was greater in the COM samples ( P < 0.05). Data also demonstrated that concentrations of microminerals like Cu, I, Fe, Mn, Se, and Zn in the organic WRM were lower ( P < 0.05) compared with the milk from CPS. The highest concentration of Ni was reported for COM ( P < 0.05); however, this value was below the minimum-risk level (MRL). Concentrations of heavy metals like As and Ni were greater in CPS milk than those in organic milk ( P < 0.05). In addition, there were greater concentrations of Cd and Pb in the WRM from CPS versus that from the organic farms. Concentration of Al was lowest in the OPS milk versus Al in the CPS which was 6.5-fold greater than in organic milk. The amount of Hg was below the MRL of 0.01 μmol/L for all production systems. A high variability was observed in the published data regarding the country of origin. Raw milk originating from Europe and North America was characterized by concentrations of macro- and microminerals below the MRLs as compared with that from specific countries, which had some minerals above the MRLs. For example, concentrations of Pb were above the MRL in the milk samples from Brazil, Croatia, Egypt, Mexico, Nigeria, Palestine, Romania, Serbia, and Turkey. Moreover, data from this study indicate that organic dairy farms are characterized by lower concentrations of toxic heavy metals in the WRM compared with those from CPS dairy farms.

Occurrence of selected metals in feed and sheep´s milk from areas with different environmental burden

The content of selected essential elements and toxic metals in feed and sheep's milk from areas with different parts of Slovak Republic was analyzed. Region of Novoť (undisturbed environment; North Slovakia) and region of Klátova Nová Ves (widely disturbed environment; Western Slovakia) were under investigation. Eleven metals have been analyzed (essential elements - calcium, zinc, selenium, iron, magnesium, copper; toxic elements - arsenic, mercury, lead, cadmium, nickel). Samples of feeds and milk were collected five-times during the year (spring and autumn season). Analyses of samples were performed by certified testing laboratory Eurofins Bel/Novamann (Nové Zámky, Slovak Republic). Analyses were performed by routine methods, according to the valid methodologies. The results showed significantly higher content of selected essential elements in feed in spring season from area with widely disturbed environment (Klátova Nová Ves). Significantly higher content of essential elements in milk was on farm of Novoť (undisturbed environment). Occurrence of toxic metals in feed from area with widely disturbed environment in spring season did not affect their content in milk. It can be concluded, that the use of milk of sheep from these areas for direct use or for dairy products processing is appropriate, safe and poses no health risk for the consumers.

Developmental selenium exposure and health risk in daily foodstuffs: A systematic review and meta-analysis

Selenium (Se) is a trace mineral and an essential nutrient of vital importance to human health in trace amounts. It acts as an antioxidant in both humans and animals, immunomodulator and also involved in the control of specific endocrine pathways. The aim of this work is to provide a brief knowledge on selenium content in daily used various foodstuffs, nutritional requirement and its various health consequences. In general, fruits and vegetables contain low content of selenium, with some exceptions. Selenium level in meat, eggs, poultry and seafood is usually high. For most countries, cereals, legumes, and derivatives are the major donors to the dietary selenium intake. Low level of selenium has been related with higher mortality risk, dysfunction of an immune system, and mental failure. Selenium supplementation or higher selenium content has antiviral outcomes and is necessary for effective reproduction of male and female, also decreases the threat of chronic disease (autoimmune thyroid). Generally, some advantages of higher content of selenium have been shown in various potential studies regarding lung, colorectal, prostate and bladder cancers risk, nevertheless results depicted from different trials have been diverse, which perhaps indicates the evidence that supplementation will merely grant advantage if the intakes of a nutrient is deficient. In conclusion, the over-all people should be advised against the usage of Se supplements for prevention of cardiovascular, hepatopathies, or cancer diseases, as advantages of Se supplements are still ambiguous, and their haphazard usage could result in an increased Se toxicity risk. The associations among Se intake/status and health, or disease risk, are complicated and need exposition to notify medical practice, to improve dietary recommendations, and to develop adequate communal health guidelines.

What do we know about exposure of Iranians to cadmium? Findings from a systematic review

Cadmium is an important environmental contaminant. High consumption of chemical fertilizers and industrial activities in recent decades has caused people to be worried about exposure to cadmium. There is no policy for environmental and biological monitoring of exposure to cadmium in the general population in Iran. This study was aimed to review cadmium content in consuming foods and biological samples in Iran, systematically. We developed a comprehensive search strategy and used it to search on Web of Science, Scopus, Science Direct, and Scientific Information Database until 28 December 2016. The totals of 285 articles were identified and finally 31 original papers were selected. Cadmium contamination was found in Iranian food groups such as rice, cereal and legumes, canned tuna fish, vegetables, fruit juice, and egg. This study showed that cadmium amount in 75% of the consumed rice samples (domestic and imported) was higher than the maximum limits approved by institute of standards and industrial research of Iran. Lettuce samples in Yazd were recorded the highest concentration of cadmium compared to other studies. In addition, high amount of cadmium was observed in the blood of the general population. Regarding the cadmium contamination in food and blood samples in Iran, policies must be adopted to reduce exposure to cadmium through different matrices as much as possible.

Detection of selected trace elements in yogurt components

The objective of this study was to determine the concentrations of Cu, Cd, Pb, Mn, Cr, Co, Ni, Zn, and Hg in the white and fruit parts of commercially available yogurts (n = 30) from Nitra markets (Slovak Republic). The results were correlated to determine their relationships. Three yogurt fruit flavors were chosen and tested, strawberry (n = 10), blueberry (n = 10), and cherry (n = 10). The elements were analyzed using atomic absorption spectrophotometry. Higher concentrations of toxic elements, such as Cd and Pb, were found in the fruit parts of the yogurt, and in some cases, the tolerable limit was exceeded. The white part of the yogurt was not contaminated by toxic elements. White yogurt is a good source of nutrients for humans, but the fruit part in yogurt requires detailed monitoring and improvements in the processing techniques.

Heavy metals in cow's milk and cheese produced in areas irrigated with waste water in Puebla, Mexico

The aim of this work was to determine Ni, Cr, Cu, Zn, Pb, and As levels in raw milk and Oaxaca and ranchero type cheeses, produced in areas irrigated with waste water from Puebla in Mexico. Milk results showed a mean Pb level of 0.03 mg kg^-1, which is above the maximum limit as set by Codex Alimentarius and the European Commission standards. For As a mean value of 0.12 mg kg^-1 in milk was obtained. Mean As and Pb levels in milk were below the Mexican standard. Milk whey and ranchero cheese had mean Pb levels of 0.07 and 0.11 mg kg^-1, respectively. As was higher in Oaxaca and ranchero cheese at 0.17 and 0.16 mg kg^-1, respectively. It was concluded that cheeses made from cow's milk from areas irrigated with waste water are contaminated with Pb and As, which may represent a health risk.

The effect of terebinth (Pistacia terebinthus L.) coffee addition on the chemical and physical characteristics, colour values, organic acid profiles, mineral compositions and sensory properties of ice creams

The aim of this research was to evaluate the effect of terebinth (Pistacia terebinthus L.) coffee addition (0.5, 1 and 2 %) on the chemical and physical properties, colour values, organic acid profiles, mineral contents and sensory characteristics of ice creams. The total solids, fat, titratable acidity, viscosity, first dripping time and complete melting time values, a (*) and b (*) colour properties, citric, lactic, acetic and butyric acid levels and Ca, Cu, Mg, Fe, K, Zn and Na concentrations of ice creams showed an increase with the increment of terebinth coffee amount, while protein, pH, L (*), propionic acid and orotic acid values decreased. However, Al and malic acid were not detected in any of the samples. The overall acceptability scores of the sensory properties showed that the addition of 1 % terebinth coffee to the ice cream was more appreciated by the panellists.