Comparative study of heavy metals in dried and fluid milk in Peshawar by atomic absorption spectrophotometry

Concentration of heavy metals in pasteurized and sterilized milk and health risk assessment across the globe: A systematic review

OBJECTIVE

Although milk and dairy products are almost complete food, they can contain toxic heavy elements with potential hazards for consumers. This review aims to provide a comprehensive report on the occurrence, concentration, and health risks of selected heavy metals in pasteurized and sterilized milk recorded worldwide.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) was used to develop this systematic review. Databases included the Web of Knowledge, Scopus, Scientific Information Database, Google Scholar, and PubMed from inception until January 2023. Keywords related to the terms "Heavy metals", "Arsenic" and "Pasteurized and sterilized milk" and "Risk Assessment" were used. The potential health risks to human health from milk daily consumption were estimated using extracted data on heavy metals concentration based on metal estimated daily intake, target hazard quotient, and carcinogenic risk.

RESULTS

A total of 48 potentially relevant articles with data on 981 milk samples were included in the systematic review. Atomic Absorption Spectroscopy, atomic absorption spectroscopy, inductively coupled plasma-mass spectrometry, and inductively coupled plasma-optical emission spectrometry were the most common valid methods to measure heavy metals in milk samples. Following the initial evaluation, Cu, Cd, Zn, and Pb were the most contaminants, which exceeded the maximum permissible criteria in 94%, 67%, 62%, and 46% of the milk samples tested. Relying on target hazard quotient and carcinogenic risk results, milk consumers in 33(68.75%) and 7 (14.5%) studies were exposed to moderate to high levels of carcinogenic and non-carcinogenic risk, respectively. The highest level of risk is due to the consumption of pasteurized and sterilized milk detected in Pakistan, Brazil, Egypt, Slovakia, and Turkey.

CONCLUSION

The elevated levels of heavy metals in milk samples, especially Pb and Cd is a public health concern; therefore, maximum control and strict regulations must be adopted to decrease heavy metals contaminants in the dairy industry. Further studies are required to develop safe milk processing and handling methods for the decontamination of heavy metals in milk and its products.

Dietary Intake and Exposure Assessment of Trace Elements in Infants' Diets: A Case Study in Kuwait

Different types of infant foods categorized as formulas, cereals, and purees imported from seven different countries and available on the Kuwaiti retail market were collected to determine the elemental content, including essential trace elements namely chromium (Cr), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), selenium (Se), and molybdenum (Mo); potentially toxic trace elements such as aluminum (Al), nickel (Ni), tin (Sn), antimony (Sb), and uranium (U); and toxic trace elements including arsenic (As), lead (Pb), cadmium (Cd), and mercury (Hg). The samples were analyzed using ICP-MS. An extensive literature search illustrated the uniqueness of this study since seven different essential elements, five different potentially toxic elements, and four different toxic trace elements were measured in a variety of infant foods; in addition, the different trace etlemental levels measured in the investigated infant foods were compared to the ones associated with the different infant foods types reported in the literature. The essential trace element concentrations detected in this study were implemented to calculate their total daily intake, where the calculated daily intake values were compared to their recommended dietary allowance (RDA) to assess the percentage total daily intake for the essential trace elements. Further, the calculated potentially toxic and toxic trace elements daily intake values were used to assess the potential health risks to infants incurred by consuming different infant foods by calculating the hazard quotient (HQ), while the margin of exposure (MOE) was calculated for the toxic ones only. It was concluded that infant formulas and foods should be added to the infant diet in addition to breast milk to meet specific nutritional needs. This study confirms that infants are exposed to toxic trace elements via diet, warranting careful attention to diet choices both to limit this exposure and to avert potentially hazardous adverse health effects to the infants. However, based on the calculated hazard quotients (HQs) and margin of exposures (MOEs), consuming breast milk in addition to almost all different types of infant foods is considered safe and unlikely to contribute to infants' non-cancerous health hazards.

Assessing heavy metal levels in pediatric enteral nutrition formulas available in the Turkish market: Implications for consumer health

In this study, we assessed the levels of lead (Pb), cadmium (Cd), mercury (Hg), and inorganic arsenic (iAs) in 27 pediatric enteral nutrition (EN) formulas from five international brands available in the Turkish market. Analysis was conducted using inductively coupled plasma mass spectrometry (ICP-MS). Non-carcinogenic and carcinogenic risk assessment was performed using hazard quotient (HQ), hazard index (HI), carcinogenic risk (CR), Toxicological contribution % of Provisional Tolerable Weekly Intake (PTWI) models. Our objective was to evaluate heavy metal exposure in EN formulas, specifically focusing on Cd, Pb, iAs, and Hg levels according to recommended amounts for different age groups based on their energy requirements. Average concentrations of iAs in polymeric (PC), oligomeric (OC), and monomeric (MC) EN formulas were as follows: PC: 2.13 ± 0.16 ( Collapse

Key Words

• Carcinogenic risk
• Enteral nutrition formula
• Hazard quotient
• Health risk assessment
• Heavy metal

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MESH Headings

• Female
• Child
• Humans
• Male
• Cadmium/analysis
• Enteral Nutrition
• Lead
• Metals, Heavy/analysis
• Mercury/analysis
• Risk Assessment

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Affiliation(s)

Gursel Isci Department of Nutrition and Dietetics, Faculty of Health Sciences, Agri Ibrahim Cecen University, 04100, Agri, Turkey.
Betul Orucoglu Department of Nutrition and Dietetics, Faculty of Health Sciences, Afyonkarahisar Health Sciences University, 03100, Afyonkarahisar, Turkey.
Merve Ekici Department of Nutrition and Dietetics, Faculty of Health Sciences, Agri Ibrahim Cecen University, 04100, Agri, Turkey; Department of Nutrition and Dietetics, Institute of Health Sciences, Acıbadem Mehmet Ali Aydınlar University, 34758, Istanbul, Turkey.

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Comparison between pollutants found in breast milk and infant formula in the last decade: A review

Since ancient times, breastfeeding has been the fundamental way of nurturing the newborn. The benefits of breast milk are widely known, as it is a source of essential nutrients and provides immunological protection, as well as developmental benefits, among others. However, when breastfeeding is not possible, infant formula is the most appropriate alternative. Its composition meets the nutritional requirements of the infant, and its quality is subject to strict control by the authorities. Nonetheless, the presence of different pollutants has been detected in both matrices. Thus, the aim of the present review is to make a comparison between the findings in both breast milk and infant formula in terms of contaminants in the last decade, in order to choose the most convenient option depending on the environmental conditions. For that, the emerging pollutants including metals, chemical compounds derived from heat treatment, pharmaceutical drugs, mycotoxins, pesticides, packaging materials, and other contaminants were described. While in breast milk the most concerning contaminants found were metals and pesticides, in infant formula pollutants such as metals, mycotoxins, and packaging materials were the most outstanding. In conclusion, the convenience of using a feeding diet based on breast milk or either infant formula depends on the maternal environmental circumstances. However, it is important to take into account the immunological benefits of the breast milk compared to the infant formula, and the possibility of using breast milk in combination with infant formula when the nutritional requirements are not fulfilled only with the intake of breast milk. Therefore, more attention should be paid in terms of analyzing these conditions in each case to be able to make a proper decision, as it will vary depending on the maternal and newborn environment.

Evaluation of Potentially Toxic Trace Metals and Associated Health Risk Assessment in Buffalo Milk

The contamination of toxic trace metals in the food chain is one of the major threats to human health. Milk is part of a balanced diet, which is essential for proper growth, but the ingestion of contaminated milk may cause chronic health disorders. The present study is focused on the assessment of contamination of toxic trace metals in buffalo milk and the associated health risks to the consumers of Abbottabad, Pakistan. Standard analytical methods were employed to quantify the metal contents in the milk samples collected from various shops and homes in the months from June 2021 to October 2021. Health risk assessment was accomplished by computing estimated daily intake (EDI), health risk index (HRI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TCR). On a comparative basis, the mean concentration of Cr was found to be highest in both shop and home milk samples (101.3 ± 45.33 and 54.11 ± 24.20 mg/L, respectively), followed by Pb, Zn, Ni, and Cd levels. In buffalo milk collected from homes, the highest concentration of the metals was found in October, followed by July, September, June, and August. In shop milk, the increasing trend of metal contents was July > October > September > June > August. Significantly strong positive relationships were noted between the metal concentrations in the milk samples. Multivariate cluster analysis and principal component analysis exhibited significant anthropogenic contributions of the metals in buffalo milk. Mostly, the EDI and HRI values were exceeding the recommended limits; however, THQ, HI, and TCR showed that the intake of these metals through milk consumption was within the safe limit and thus revealed no significant carcinogenic or non-carcinogenic risks to the consumers. It is high time to ensure the continuous monitoring of organic/inorganic toxins in the milk and concerned authorities should take strict measures to control the contamination of milk and other food products.

Probabilistic Health Risk Assessment of Trace Elements in Baby Food and Milk Powder Using ICP-OES Method

This study was conducted to evaluate the concentration and health risk of trace elements in milk powder and baby food samples marketed in Iran using inductive couple plasma/optical emission spectroscopy (ICP-OES) method. The limit of detection (LOD) and limit of quantification (LOQ) were ranged from 1.80 × 10^-5 to 2.17 × 10^-3 and 6.00 × 10^-5 to 7.22 × 10^-3 mg/kg, respectively, with recoveries ranged from 92 to 105%. Zinc (Zn) was found in a high mean concentration (8.49 × 10^-1 ± 3.93 × 10^-2 mg/kg) in milk powder, and iron (Fe) was found in the highest mean concentration (2.04 ± 3.61 × 10^-2 mg/kg) in baby food. The Monte Carlo simulation results for the infants revealed that the rank order of the hazard quotient (HQ) index was mercury (Hg) > nickel (Ni) > arsenic (As) > cadmium (Cd) > aluminum (Al). Further, the result of non-carcinogenic and probability of carcinogenic risk was lower than the limits of safe risk (HQ > 1 and cancer risk (CR) > 1 × 10^-4). In conclusion, the toxic elements content in the tested products was sufficiently low, and all of the milk powder and baby food sold in Iran could be considered safe for infants and children.

A Rapid Routine Methodology Based on Chemometrics to Evaluate the Toxicity of Commercial Infant Milks Due to Hazardous Elements

The toxicity and the health risk assessment associated to the presence of some hazardous elements (HEs) in dried (infant formula and powdered) milks due to manufacturing and packaging process, raw materials used, environmental conditions, etc. need to be determined. With this aim, a new methodology based on the combination of health risk quotients and non-supervised (as cluster analysis (CA) and principal component analysis (PCA)) chemometric techniques is proposed in this study. The methodology was exemplified using the concentration of 27 elements, some of them HEs, measured in 12 powdered milk samples produced for children and adults in Brazil and Colombia. The concentration values were obtained by inductively coupled plasma-mass spectrometry (ICP-MS) after acid microwave digestion. Elemental concentrations vary depending upon the type of milk (initiation, growing-up, follow-on milks and adult milks). However, hazard quotients (HQ) and carcinogenic risk (CR) values showed no risk associated to the presence of HEs on milks. The methodology designed made possible to conclude that adults’ milks are more characteristic of elements naturally present in milk. Children milks present major presence of trace and minor elements. Between infant milks, sample H, designed for babies between 12 and 36 months, was identified as of poor quality. Moreover, it was possible to deduce that while the fortification process applied to children powdered milks is a probable metal and metalloid source, together with the manufacturing, the skimming process is not a contamination source for milks.

Graphical abstract

Modified Baby Milk-Bioelements Composition and Toxic Elements Contamination

Breast milk has the most suitable composition for the proper development in the first year of a child’s life. However, it is often replaced with artificial milk. The aim of the study was to analyze the composition of essential elements: Na, K, Ca, P, Mg, Fe, Zn, Cu, and Mn as well as toxic elements: Ni, Pb, Sr, Li, and In in 18 formulas available in Poland. The daily supply was also estimated. The study was performed by Inductively Coupled Plasma Optical Emission Spectrometry method. The results showed the presence of all essential elements tested, but the content of P and Mn significantly differed from the concentrations declared. Such discrepancies can have significant impact on the daily dose of the bioelements taken. However, the content of elements was within the reference standards established by the EU Directive with exception of P, the amount of which exceeded the norms 5.23–18.80-times. Daily supply of P in tested milk as well as Fe and Mn provided with first and hypoallergenic formula exceeded the adequate intake. Analysis revealed the contamination with harmful elements—Pb, Sr, Li, and In were detected in almost all products. The study confirms the data concerning some discrepancies in composition and the contamination of food and may provide information on the feeding quality of children and estimation of health risk associated with exposure to toxic elements.

Trace elements in starter infant formula: dietary intake and safety assessment

The aim of this study was to investigate the concentrations of five essential (Fe, Mn, Zn, Cu and Se) and four non-essential/toxic elements (Cr, Cd, Ni and Pb) in 35 different starter infant formulas (0-6 months) sold in Italy. In addition, a safety assessment of these trace elements was carried out, by comparing the estimated daily intake (EDI) with the adequate intake (AI) and the provisional tolerable daily intake (PTDI), with a view to provide information on the metal distribution patterns and health risk to infants arising from the consumption of these products. The concentrations were determined by using inductively coupled plasma mass spectrometry after microwave digestion. The concentrations expressed in geometric mean ± geometric standard deviation of Fe (6.17 ± 1.61 mg/L), Zn (6.21 ± 1.31 mg/L), Cu (416.4 ± 1.21 μg/L), Mn (121.5 ± 1.85 μg/L) and Se (13.27 ± 1.67 μg/L) were within legal limits. In spite of this, the mean EDIs of Fe (4.81 mg/day) and Mn (94.75 μg/day) were many times higher than the recommended AI, especially for Mn. Chromium, Ni, Cd and Pb concentrations were not detectable in 11, 37, 57 and 66% of the samples, respectively. Considering the overall sample, the GM ± GSD of these elements were 4.80 ± 5.35 μg/L for Cr, 1.02 ± 11.65 μg/L for Ni, 0.21 ± 14.83 μg/L for Cd and 0.14 ± 17.13 μg/L for Pb. The mean EDIs were far below the respective PTDI. When the safety assessment was based on the 75° percentile level of each elements, all EDIs remained well below the PTDI, with the exception of Cd, whose EDI approached (74.7%), albeit remaining below the PTDI. In conclusion, our results and the increased awareness on the potential risks of excessive Mn and Fe for infants support that an urgent scientific-based definition of the appropriated levels of fortification in formulas is required. Moreover, regular monitoring of all the stages of production of infant formulas is essential in order to limit toxic metal contamination.

Energy dispersive X-ray fluorescence detection of heavy metals in Bangladesh cows' milk

It is considered that cow's milk is almost complete food for human as it provides most of the micronutrients and macronutrients. The cow's milks are essential for the growth and development especially for children. The main compositions of cow's milk are protein, fat, carbohydrates, vitamins and minerals which are well defined. Presently, the study of micronutrients and toxic elements in cow's milk has been widely carried out particularly in the industrialized and polluted regions because of its possibility of contamination, and thereby health risk of the consumers. The elemental composition in local cow's milk samples in Bangladesh is not well studied yet. The present study was therefore aimed to determine the level of heavy metals (Cr, Ni, As, Cd, Hg, Pb, Mn, Cu, Zn and Fe) in cow's milk using EDXRF technique. Subsequently, the experimental data was used to calculate the human health risk through the intake of both powder and liquid cows' milk available in Bangladesh. The results showed that powder milk contains significantly higher concentration of heavy metals than liquid milk samples. The HRI (health risk index) and HI (hazard index) values for most of the elements in all milk samples were within the safe limit (<1.0) or close to safe limit (≤1.0) with an exception of Hg. However, HRI value for Hg in powder milk samples for both children and adult showed a value higher than one (>1). MPI (metal pollution index) value for powder milk samples are very high compared to other type of milk samples analyzed in this study. Therefore, it has been suggested that heavy metal contamination through local powder milk samples might have significant negative impact (threat) on human health.

"Manganese-induced neurotoxicity: a review of its behavioral consequences and neuroprotective strategies"

Manganese (Mn) is an essential heavy metal. However, Mn’s nutritional aspects are paralleled by its role as a neurotoxicant upon excessive exposure. In this review, we covered recent advances in identifying mechanisms of Mn uptake and its molecular actions in the brain as well as promising neuroprotective strategies. The authors focused on reporting findings regarding Mn transport mechanisms, Mn effects on cholinergic system, behavioral alterations induced by Mn exposure and studies of neuroprotective strategies against Mn intoxication. We report that exposure to Mn may arise from environmental sources, occupational settings, food, total parenteral nutrition (TPN), methcathinone drug abuse or even genetic factors, such as mutation in the transporter SLC30A10. Accumulation of Mn occurs mainly in the basal ganglia and leads to a syndrome called manganism, whose symptoms of cognitive dysfunction and motor impairment resemble Parkinson’s disease (PD). Various neurotransmitter systems may be impaired due to Mn, especially dopaminergic, but also cholinergic and GABAergic. Several proteins have been identified to transport Mn, including divalent metal tranporter-1 (DMT-1), SLC30A10, transferrin and ferroportin and allow its accumulation in the central nervous system. Parallel to identification of Mn neurotoxic properties, neuroprotective strategies have been reported, and these include endogenous antioxidants (for instance, vitamin E), plant extracts (complex mixtures containing polyphenols and non-characterized components), iron chelating agents, precursors of glutathione (GSH), and synthetic compounds that can experimentally afford protection against Mn-induced neurotoxicity.