Libyan International Medical University Journal

ORIGINAL ARTICLE
Year
: 2019  |  Volume : 4  |  Issue : 1  |  Page : 10--17

Determination of some heavy metals in cosmetic products collected from Benghazi-Libya markets during 2016


Salwa Y.S. Rahil1, Intisar A Elshara1, Nagwa H.S. Ahmida2, Mohamed H.S. Ahmida3,  
1 Department of Chemistry, Faculty of Science, University of Benghazi, Benghazi, Libya
2 Department of Environmental Health, Faculty of Public Health, University of Benghazi, Benghazi, Libya
3 Department of Nutrition, Faculty of Public Health, University of Benghazi, Benghazi, Libya

Correspondence Address:
Prof. Nagwa H.S. Ahmida
Department of Environmental Health, Faculty of Public Health, University of Benghazi, Benghazi
Libya

Abstract

Introduction: Cosmetics have been utilized by most of the people irrespective of their race, gender, or age to beautify, modify, or improve the physical appearance. Many cosmetic products contain heavy metals as ingredients or impurities. Recent research has reported that these metals can cause many types of health and skin problems. Aims: The aim of this study is to detect the levels of heavy metals in some cosmetic products that are available in cosmetic shops around the city of Benghazi. Materials and Methods: Twenty-five of cheap facial cosmetic products that are widely in demand in cosmetic shops in Benghazi were collected in April 2016. The samples included eight kohl, seven eyeliners, and ten lipsticks. Metals including iron, copper, chromium, zinc, lead, and cadmium were analyzed in the selected samples using flame atomic absorption spectrophotometer after suitable digestion process. Results: Our results indicated that iron and copper were detected in all samples with concentration ranges varying from 0.5 to 124.5 mg/kg for iron and 1.8–51.4 mg/kg for copper. The concentration ranges of chromium, zinc, cadmium, and lead were varied from 0.0 to 7.25 mg/kg, 0.0 to 22.75, 0.0 to 125.0 mg/kg, and 0.0 to 20.25 mg/kg, respectively. Conclusions: The results showed that the selected metals were detected in most of the samples at varying concentrations. Kohl samples have the highest concentration of the analyzed metals. According to the maximum allowed limits recommended by the World Health Organization (WHO) for toxic metals in cosmetics, there was only one sample that had lead concentration higher than the maximum limit recommended by the WHO. In addition, there were twenty samples that had concentrations of cadmium above the WHO legislation limits.



How to cite this article:
Rahil SY, Elshara IA, Ahmida NH, Ahmida MH. Determination of some heavy metals in cosmetic products collected from Benghazi-Libya markets during 2016.Libyan Int Med Univ J 2019;4:10-17


How to cite this URL:
Rahil SY, Elshara IA, Ahmida NH, Ahmida MH. Determination of some heavy metals in cosmetic products collected from Benghazi-Libya markets during 2016. Libyan Int Med Univ J [serial online] 2019 [cited 2019 Oct 22 ];4:10-17
Available from: http://journal.limu.edu.ly/text.asp?2019/4/1/10/259179


Full Text



 Introduction



Cosmetics are defined as any substance or preparation intended to be placed in contact with the various external parts of the human body or applied to the teeth and the mucous membranes of the oral cavity. Cosmetics are mainly used for the purpose of cleaning, perfuming, protection, changing their appearance, correcting body odors, and keeping the surfaces in good condition.[1] Cosmetic products contain thousands of chemical substances; a group of these dangerous substances are heavy metals, such as lead, cadmium, nickel, arsenic and mercury, chromium, iron, copper, and cobalt.[2],[3],[4] Those metals and their compounds were used for different purposes in the cosmetic industry, mainly as ultraviolet filters in face and body care products and pigments in colored cosmetics.[2] The presence of heavy metals in cosmetic products cannot be forbidden. The cosmetic products may also be contaminated using metal-coated apparatuses during cosmetic production processes.[1],[5] Owing to the harmfulness of metals to human health, their presence in cosmetic products is restricted by several global health regulations such as World Health Organization (WHO)[6] and health legislations in various countries, including Germany,[6],[7] Canada,[8] Jordan,[9] and European Union (EU) countries.[2],[6] These regulations and their limits are based to provide a high level of protection to a consumer.

As a result of the health-related toxic effects of heavy metals, it is necessary to monitor commercially available cosmetics regarding the concentrations of metals, in order to recognize whether the concentrations are within the safe values ranges for human health. Atomic absorption spectrometry (AAS) and inductively coupled plasma mass spectrometry are used to analyze the metal in cosmetic samples. In fact, prior to quantification of heavy metals, cosmetic sample should undergo a digestion process, to convert the components of matrix into simple chemical forms. Numerous methods, including wet-digestion and dry-ashing digestion methods, have been proposed to prepare cosmetic sample for elemental analysis.[10],[11],[12],[13]

There are plenty of information about the detection of toxic metals in colored cosmetics, especially in Arab Countries.[14],[15],[16],[17],[18],[19] However, no attempts have been done to investigate the presence of heavy metals in samples from cosmetic product shops in the city of Benghazi. Therefore, the purpose of this study was to identify the safety of some facial cosmetic products that are widely vended in stored around the city of Benghazi by determination of the heavy metals (including lead, cadmium, iron, copper, chromium, and zinc) using flame atomic absorption spectrophotometer (FAAS).

 Materials and Methods



In this study, 25 of facial cosmetic products, including 8 kohl, 7 eyeliners, and 10 lipsticks, were purchased from cosmetic product shops in Benghazi, Libya. Most of these products are imported from countries that have weak regulatory inspection and screening as well as no standards for manufacturing. The prices of the selected cosmetic products ranged from 1 to 10 Libyan dinars. Codes are assigned to the products in place of their brand names as shown in [Table 1]. The information on the container labels and contents were carefully examined visually and noted for any defects or irregularities, such as cracks or leaks. Name of products, dates of manufacture and of expiry, preservative used, if any, as well as ingredient list on the labels of these products were noted and reported in [Table 1].{Table 1}

Chemicals and reagents

All chemicals and reagents that were used in the experimental work were of analytical grade. These chemicals included concentrated nitric acid (65%, Codex) and perchloric acid (70%, Merck). Hydrogen peroxide (30%) and sulfuric acid (98%) were obtained from Hopkin and Williams Chemical Ltd. Standard stock solutions (1000 ppm) of cadmium, chromium, copper, iron, zinc, and lead were purchased from Scharlau. These standards were used to prepare calibration solutions. Distilled deionized water was used for the preparation of all solutions.

Before the experiments were carried out, the glassware containers were soaked in water and soap and rinsed several times with tap water and then soaked them for 24 h in bath containing 10% nitric acid solution, to clear out any metal on the glassware surface. The containers were rinsed thoroughly with deionized water.[20],[21]

Procedure

The kohl and eyeliner samples were dried to constant weight in an oven at 80°C for 12 h. The dried samples were grounded and homogenized in a mortar. About 0.1 g of sample was weighed in a clean test tube. The sample was digested with 5.0-ml nitric acid and 2.5-ml hydrogen peroxide using hot block digester (Grant QBT2 Digital Block Heater, England). The sample was heated at 60°C for 15 min. The heat was then increased to 130°C and digested for 1 h.[22],[23]

Lipstick samples were first crushed in an agate mortar and then mixed well. About 0.25 g of each sample was weighed out in a test tube, and 2 ml of nitric acid, 2 ml of sulfuric acid, and 1 ml of perchloric acid were added.[1] Then, the digestion process was followed as mentioned for kohl and eyeliner samples.

After the digestion process, sample solutions were allowed to cool and then poured into 25-ml volumetric flask. The sample remaining in the tube was removed by rinsing several times with deionized water. The rinsing water was mixed with the previous sample in the flask and was used to make the solution up to the mark. The sample solution then was filtered using Whatman No. 41 filter paper. The absorbance of each sample solution was measured using FAAS (GBC model 932 Plus FAAS with GBC Avanta Software, version 1.33, GBC Scinetific Eqipment Ltd., Braeside, Victoria, Australia). The operating conditions adjusted in the spectrometer were carried out according to the standard guidelines of the manufacture. The concentrations of the elements in the sample solutions were determined from curves of absorbance versus concentration of the standard solutions. Blank solutions were prepared under identical conditions.[24]

Statistical analysis

All the experiments of metal analysis were performed in duplicate, and the results were expressed as mean (mg/kg) ± standard deviation (mean ± SD). The analytical determination data were tested for normality distribution using the Shapiro–Wilk test.[25] When the data were normally distributed, the parametric statistical tests of mean comparison were applied. In this case, the comparisons between the different cosmetic products were performed by the one-dimensional variance analysis (one-way ANOVA) test, followed by the least significant difference test. For the data that did not follow a normal distribution, nonparametric Kruskal–Wallis test was performed.[26] All the statistical analysis and quality control tests were carried out using the Statistical Package for the Social Sciences (SPSS) (SPSS version 19.0; IBM, Chicago, Illinois, USA) Program, adopting the significance level of 5% (P < 0.05).

 Results



The results of analysis of six heavy metals, including chromium, copper, iron, zinc, lead, and cadmium, using FAAS in cosmetic samples were shown in [Table 2] and [Table 3].{Table 2}{Table 3}

Significant levels of iron have been found in all cosmetic samples ranging from 1.625 to 27.57 mg/kg in kohl, from 0.50 to 9.95 mg/kg in eyeliner, and from 0.6 to 124.5 mg/kg in lipstick. The highest concentration of iron was detected at 124.50 mg/kg in sample L8. There is no available internationally acceptable maximum limit for iron in cosmetic products.[5],[27]

Copper was also detected in all cosmetic samples, with concentrations ranging from 0.95 to 51.40 mg/kg [Table 2]. The highest concentration was detected in lipstick (sample L6), whereas the lowest concentration was detected in eyeliner (sample E5).

The total concentration of chromium in the cosmetic samples ranged from 0.30 to 7.25 mg/kg, [Table 2]. The highest concentration (7.25 mg/kg) was obtained in sample A8, whereas the lowest concentration of 0.30 mg/kg was found in sample L9.

The concentration of zinc ranged from 0 (not detected [ND]) to 22.75 mg/kg. The highest concentration was detected in sample A8. The eyeliner and lipstick samples had a maximum concentration of zinc recorded at 7.70 mg/kg (sample E3) and 5.05 mg/kg (sample L3), respectively.

The statistical analysis of the results in [Table 2] showed that no statistically significant differences between kohl, eyeliners, and lipsticks, were observed for the content of iron, chromium, copper, and zinc.

The toxic metals such as lead and cadmium were also analyzed in the cosmetic samples. Lead was detected in all types of investigated cosmetic samples, mostly present in kohl samples, with concentration ranging from ND to 20.25 mg/kg, while the concentration of cadmium ranged from ND to 125.0 mg/kg. The highest concentration detected was in sample A1 [Table 3].

The statistical analysis of the toxic metals in cosmetic samples gave P value corresponding to 0.599 and 0.029 for analysis results of lead and cadmium, respectively [Table 3]. These values indicated that there were no significant differences for lead concentrations in the types of cosmetic products, whereas significant differences were observed for cadmium concentrations in cosmetic products (P < 0.05). The results indicated that the concentrations of cadmium in kohl samples were significantly difference from eyeliner and lipstick samples.

 Discussion



In this study, 25 individual cosmetic products were tested to determine the concentration of some heavy metals. The products were sold by a distinct seven companies, such as Beauty, Final Touch, Loreal, Ever Beauty, Flormar, Flormasi, Khojati Herbal Company, as shown in [Table 1]. These products represented the common cosmetics sold in local markets in Benghazi. [Table 1] presents the container label disclosures for the brands of selected samples. In this study, only six products disclosed the manufacture and expiry dates of their production. Those dates are very important and must be determined to provide guides of the time frame that can be reasonably guaranteed. Three of the seven manufactures gave indications of the ingredients, and with regard to batch numbers of products, only one company (Khojati Herbal Company, India) gave the batch number of the product. Nondisclosure of batch number, meaning that in the event of a defective product being accidentally released into the market, recalls would be extremely difficult to effect.[28]

Iron and copper metals were detected in all cosmetic samples, whereas chromium and zinc were detected in 48% of the samples. Although some metals such as chromium, copper, iron, and zinc, in trace amounts, play important biochemical roles in many organisms, the toxic effects are observed at high concentrations. All those metals can lead to damaged or reduced central nervous system functions and damage to blood composition, lungs, kidney, liver, and other vital organs. Long-term exposure may result in slowly progressive physical, muscular, and neurological degenerative processes that mimic Alzheimer's disease, Parkinson's disease, muscular dystrophy, and multiple sclerosis.[29]

Although EU regulation has suggested that the concentration of some heavy metals, such as chromium, in color additive cosmetics should be <1.0 mg/kg,[2] there were eight samples with chromium concentration higher than EU standard in cosmetic products. The presence of chromium in the body facilitates the entry of glucose into cell.[30] However, exposure to high levels of chromium has been linked to kidney and lung damage and other cancers. Chromium is also linked to skin effects such as eczema and other inflammations of the skin.[7]

Zinc was detected in 12 samples. Mahmood et al. reported that zinc oxide was probably used in kohl because of its powerful natural sunblock property.[31] Furthermore, zinc is necessary for oxygen metabolism and mitochondrial function.[4],[32]

The toxic metals, such as lead and cadmium, were detected in some samples. However, the WHO sets maximum limits at 10.0 and 0.3 mg/kg, for lead and cadmium in cosmetic products, respectively.[6],[7] [Figure 1]a and [Figure 1]b shows the comparison of the levels of lead and cadmium that were detected in the investigated samples with the maximum allowed limits of these metals recommended by the WHO in cosmetics. [Figure 1]a shows that there was only one cosmetic sample that had a content of lead much higher than the maximum level recommended by the WHO. In fact, sample A3 contained lead metal at concentration of 20.0 mg/kg. [Figure 1]b shows that the contents of cadmium in 20 samples were above the allowed maximum limit, recommended by the WHO for cadmium in cosmetics. These toxic metals may get into the products when poor quality raw materials were used.{Figure 1}

 Conclusions



The results of elemental analysis showed that iron and copper metals were detected in all cosmetic samples, whereas chromium and zinc were detected in 48% of the samples. The concentration of the analyzed essential metals in the investigated facial cosmetic samples was in order kohl >lipstick >eyeliner. The analyzed essential metal concentrations in the facial cosmetic samples were sometimes higher than reported studies. Some of these essential metals are used as colorants in some cosmetics.

The concentrations of cadmium and lead in some cosmetic samples were above the maximum allowed limits set by the WHO. In fact, cosmetics are not safe products, but they have a high demand to use. Therefore, the public should be educated about the hazard of prolonged use of cosmetic products that contain toxic elements. Extensive and continue use of these cosmetic products could release the heavy metals slowly and cause harm to users of these products.

National standard legislations should be available for cosmetic products to monitor the safety of these products before their importing and reaching consumers. However, further studies are needed to evaluate the concentrations of metals in different types of cosmetics and body care products in order to protect consumer health.

Financial support and sponsorship

University of Benghazi (All the laboratory work has done in the analytical chemistry laboratory, Department of Environmental Health, Faculty of Public Health, Benghazi University. Furthermore, the Standards of metals and the FAAS were provided by the Nutrition Department, Faculty of Public Health, Benghazi University).

Conflicts of interest

There are no conflicts of interest.

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References

1Adepoju-Bello AA, Oguntibeju OO, Adebisi RA, Okpala N, Coker HA. Evaluation of the concentration of toxic metals in cosmetic products in Nigeria. Afr J Biotechnol 2012;11:16360-4.
2Borowska S, Brzóska MM. Metals in cosmetics: Implications for human health. J Appl Toxicol 2015;35:551-72.
3Naveed N. The perils of cosmetics. J Pharm Sci Res 2014;6:338-41. Available from: http://www.jpsr.pharmainfo.in. [Last accessed on 2018 Oct 10].
4Popoola OE, Bisi-Johnson MA, Abiodun A, Ibeh OS. Heavy metal content and antimicrobial activities of some naturally occurring facial cosmetics in Nigeria. IFE J Sci 2013;15:637-44.
5Nnorom IC, Igwe JC, Oji-Nnorom CG. Trace metal contents of facial (make-up) cosmetics commonly used in Nigeria. Afr J Biotechnol 2005;4:1133-8.
6Ackan M, Osci J, Anim AK, Zakaria N, Nyarko ES, Gyamfi ET, et al. Status of some metals contained in imported nail polish and lipsticks on the Ghanaian market. Proc Int Acad Ecol Environ Sci 2015;5:142-7.
7Umar MA, Caleb H. Analysis of metals in some cosmetic products in FCT-Abuja, Nigeria. Int J Res Cosmet Sci 2013;3:14-8.
8Government of Canada. Guidance on Heavy Metal Impurities in Cosmetics. Available from: https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/industry-professionals/guidance-heavy-metal-impurities-cosmetics.html. [Last accessed on 2017 Mar 10; Last updated on 2002 Jul 26].
9Jordan Standards and Metrology Organization. Jordanian Standard Legislation for Cosmetics-Lipstick. Jordan Standards and Metrology Organization; 1996.
10Ranasinghe P, Weerasinghe S, Kaumal MN. Determination of heavy metals in Tilapia using various digestion methods. Int J Sci Res Innov Technol 2016;3:38-48.
11Enders A, Lehmann J. Comparison of wet-digestion and dry-ashing methods for total elemental analysis of biochar. Commun Soil Sci Plant Anal 2012;43:1042-52.
12Hepp NM, Mindak WR, Cheng J. Determination of total lead in lipstick: Development and validation of a microwave-assisted digestion, inductively coupled plasma-mass spectrometric method. J Cosmet Sci 2009;60:405-14.
13Besecker K, Rhoades CB, Bradley J, Barnes KW. A simple closed-vessel nitric acid digestion method for cosmetic samples. At Spectrosc 1998;19:48-54.
14Al-Dayel O, Hefne J, Al-Ajyan T. Human exposure to heavy metals from cosmetics. Orient J Chem 2011;27:1-11.
15Alsaffar NM, Hussein HJ. Determination of heavy metals in some cosmetics available in locally markets. J Environ Sci Toxicol Food Technol 2014;8:9-12.
16Al-Qutob MA, Alatrash HM, Abol-Ola S. Determination heavy metals concentrations in cosmetics purchased from the palestinian markets by ICP/MS. Adv Environ Sci Int J Bioflux Soc 2013;5:287-93.
17Mohameed IH. Determination of heavy metals percentage in kohl and compared with eye brew that are available in locally markets. Iroquoian J Res Mark Consum Prot 2011;3:92-102.
18Badeeb OM, Ajlan RS, Walid MH. Kohl Al-Ethmed. JKAU: Med Sci 2008;15:59-67.
19Massadeh AM, El-Khateeb MY, Ibrahim SM. Evaluation of Cd, Cr, Cu, Ni, and Pb in selected cosmetic products from Jordanian, Sudanese, and Syrian Markets. Public Health 2017;149:130-7.
20Ullah H, Noreen S, Rehman A, Waseem A, Zubair S, Adnan M, et al. Comparative study of heavy metals content in cosmetic products of different countries marketed in Khyber Pakhtunkhwa, Pakistan. Arab J Chem 2017;10:10-8.
21Ziarati P. Determination of contaminants in some Iranian popular herbal medicines. J Environ Anal Toxicol 2012;2:2161-3.
22Nourmoradi H, Foroghi M, Farhadkhani M, Vahid Dastjerdi M. Assessment of lead and cadmium levels in frequently used cosmetic products in Iran. J Environ Public Health 2013;2013:962727.
23Sukender K, Jaspreet S, Sneha D, Munish G. AAS estimation of heavy metals and trace elements in Indian herbal cosmetic preparations. Res J Chem Sci 2012;2:46-51.
24Association of Official Analytical Chemistry. Color Additives-Metals and other Elements. In: Helric K, editor. Official Methods of Analysis. 15th ed. Arlington, Virginia: Association of Official Analytical Chemists, International; 1990. p. 1132-6.
25Razali NM, Wah YB. Power comparisons of Shairo-Wilk, Kolomogorov-Smirnov, Lillie Fors and Anderson-darling tests. J Stat Model Anal 2011;2:21-33.
26Chang YH. Biostatistics IO2: Quantitative data-parametric & non-parametric tests. Singapore Med J 2003;44:391-6.
27Lansdown AB. Iron: A cosmetic constituent but an essential nutrient for healthy skin. Int J Cosmet Sci 2001;23:129-37.
28Hugbo PG, Onyekweli AO, Igwe I. Microbial contamination and preservative capacity of some brands of cosmetic creams. Trop J Pharm Res 2003;2:229-34.
29Ouremi OI, Ayodele OE. Lipsticks and nail polishes: Potential sources of heavy metal in human body. Int J Pharm Res Allied Sci 2014;3:45-51.
30Krejpcio Z. Essentiality of chromium for human nutrition and health. Pol J Environ Stud 2001;10:399-404.
31Mahmood ZA, Zoha SM, Usmanghani K, Hasan MM, Ali O, Jahan S, et al. Kohl (surma): Retrospect and prospect. Pak J Pharm Sci 2009;22:107-22.
32Biswas A, Das KP. Zn2+ enhances the molecular chaperone function and stability of α-crystallin. Biochemistry 2008;47:804-16.