Determination and Assessment of the Toxic Heavy Metal Elements Abstracted from the Traditional Plant Cosmetics and Medical Remedies: Case Study of Libya

Characterization of Factors Affecting Stripping Voltammetry on Thermoplastic Electrodes

Thermoplastic carbon electrodes (TPEs) are an alternative form of carbon composite electrodes that have shown excellent electrochemical performance with applications in biological sensing. However, little has been done to apply TPEs to environmental sensing, specifically heavy metal analysis. The work here focuses on lead analysis and based on their electrochemical properties, TPEs are expected to outperform other carbon composite materials; however, despite testing multiple formulations, TPEs showed inferior performance. Detailed electrode characterization was conducted to examine the cause for poor lead sensing behavior. X-Ray photoelectron spectroscopy (XPS) was used to analyze the surface functional groups, indicating that acidic and alkaline functional groups impact lead electrodeposition. Further, scanning electron microscopy (SEM) and electrochemical characterization demonstrated that both the binder and graphite can influence the surface morphology, electroactive area, and electron kinetics.

Lead and arsenic contamination in henna samples marketed in Iran

Since ancient times, people around the world have used natural cosmetics to improve or change the appearance of their nails, skin, and hair. Henna is a plant-based dye that has been used over the centuries for medical and cosmetic purposes. The present work was aimed to investigate the presence of lead (Pb) and arsenic (As) in various types of commonly consumed henna samples in Iran. A total of thirty-nine henna samples from both local and imported products (3 colors in 13 brands) were randomly collected from popular and herbal medicine markets. The atomic absorption spectrometry (AAS) technique was used for the analysis of the samples. The amount of Pb and As in 100% samples was higher than the calculated limit of quantitation (LOQ). The concentrations of Pb and As in the samples were at the ranges of 9.56-16.94 μg/g and 0.25-1.12 μg/g, respectively. The mean level of Pb was higher in black and red products, compared with the green henna. The levels of Pb and As in 53.85% and 7.7% of the henna samples exceeded the permissible limits recommended by the World Health Organization (WHO), respectively. In addition, the mean levels of Pb and As contamination in the imported samples were significantly higher, in comparison to the local henna samples. To our knowledge, this is the first study assessing Pb and As contamination in the henna samples consumed in Iran. Our study demonstrated that there is a potential risk of exposure to Pb through henna in the Iranian consumers.

The chemistry behind the body art: unveiling the elemental profile and heavy metal content of natural tattoos and dyes by ICP-MS

Temporary tattoos and dyes are increasing popularity as an alternative to permanent ones. However, knowledge on its elementary composition is scarce and, this scientific gap can potentially make them a source of heavy metal exposure on humans. The present research aimed to explore the possibility of using the inorganic chemical signature to characterize natural pigments-based products and to evaluate the heavy metal content in jagua temporary tattoos and henna temporary hair dyes and tattoos. Thirty-four different samples of commercial products were analyzed for the presence and quantity of eleven trace elements (Al, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Ba, and Pb) by inductively coupled plasma mass spectrometry (ICP-MS). The overall mean concentrations varied between 0.02 and 973 μg g^-1 in solid samples or 0.01-1878 μg g^-1 for paste ones, wherein potential fake products were uncovered. None of the 34 samples considered comply with the current European Cosmetics Regulation. Samples were differentiated according to their Cr, Zn, Ba, and Pb content. The overall results revealed highly variable levels in the investigated samples, which leads us to suggest detailed quality controls of these materials, due the fact that their continued use can origin potential threat to human health.

An Investigation for Heavy Metals’ Contamination in Farmers’ Fingernails: Case Study in Libya

This study aims to assess the concentration levels of heavy metals, which are associated with health hazards: arsenic (As), cadmium (Cd), and lead (Pb) among Libyan farmers using fingernails as a biomarker. Factors that may contribute for accumulation of these toxic heavy metals in the farmers’ fingernails were also evaluated. This cross-sectional study involved 127 farmers and 25 high school teachers living in the same geographical area as the farmers (served as the control group). Fingernail samples of the participants were collected, treated, and analyzed by inductively coupled plasma mass spectrometry (ICP-MS) for As, Cd, and Pb contents after microwave acid digestion. Results of this study indicated that the concentration levels of the investigated heavy metals in fingernail samples of both participating farmers and control group were in order of Pb > Cd > As. Also, the results showed that As, Cd, and Pb levels in the farmers’ fingernails were found to be higher than in the control group by about 9-, 5-, and 2-fold, respectively. This difference for all heavy metals analyzed was found to be statistically significant $\left(P<0.05\right)$ . As a conclusion, the results of this study clearly indicated that Libyan farmers have been exposed to high levels of toxic heavy metals as a result of their agricultural activities compared with the general population living in the same geographical area as farmers, which, in turn, pose a high risk to their health. Thus, toxicological, epidemiological, and clinical studies for the Libyan farmers are strongly recommended.

Cobalt and lead concentrations in cosmetic products sold at local markets in Saudi Arabia

Cosmetics are products that can be used on the human body for cleaning, beautification or enhancing perceived attractiveness. Cosmetics may contain a variety of heavy metals such as cobalt (Co) and lead (Pb), which at high concentrations may pose adverse effects on human health. This study focuses to measure the concentration of heavy metals (Co and Pb) in some cosmetic samples of four types (foundation, skin lighteners, kajal (kohl) and lawsone (henna)) available at local markets in Saudi Arabia. The total number of all cosmetic samples understudy was 41. The samples were analysed using atomic absorption spectroscopy to measure the content of Co and Pb. Quality control of the data was performed using Standard Reference Materials [IAEA-V-10] hay powder. For all cosmetic types and qualities combined, the Co concentration range was determined to be 21.14 ± 3.70-144.91 ± 2.27 μg/g and the Pb range 0.75 ± 0.00-10.60 ± 1.24 μg/g. The Co concentration in all cosmetic types understudy was higher than the recommended level. Pb concentration was within the range recommended by the United States Food and Drug Administration in all types of cosmetics except for kohl, for which 22 % of the samples contained concentrations higher than the permissible limit. The findings of this study call for immediate and ongoing testing to monitor the concentrations of toxic metals in cosmetic products used in Saudi Arabia to ensure that established limits are respected and thereby protect consumer health.

Determination of essential and non-essential elements in Xylanthemum macropodum of Balochistan, Pakistan

Background: Medicinal plants have been used to treat various diseases for several years throughout the world. Xylanthemum macropodum is a medicinal plant with a vast application as a home remedy in Balochistan. Objective: The current study was conducted to determine the levels of essential and non-essential elements in Xylanthemum macropodum collected from Quetta (Balochistan, Pakistan). Methods: Analysis was conducted for eleven elements by using atomic absorption spectrophotometer and flame photometer. Results: The essential and non-essential elements that were detected in Xylanthemum macropodum are K, Na, Ca, Fe, Cu, Co, Ni, Mn, Cr, Cd and Pb, respectively. The result of the concentration of determined elements are in the order of K> Na> Ca> Fe> Cu> Co> Ni> Mn> Cd> Cr> Pb in Xylanthemum macropodum 3000> 1600> 790.25> 92.36> 85.31> 49.24> 40.94> 20.94> 6.655> 1.61> 1.18 µg/g respectively. Conclusions: Mn, Na and Pb were found within the permissible limit given by World Health Organization, while Ca, Cu, Fe, Ni, Cd and Cr were beyond the permissible limits. However, there is no permissible limit for K and Co.

Appraisal of a novel extraction technique for estimation of cadmium content in pea seedlings based on human health risk assessment

In this study, a novel extraction and safety evaluation method for heavy metals based on different functions of plants was proposed, and an edible plant (pea) was used as the research material to explore the feasibility of the novel method. Pea sprouts were cultured in cadmium (Cd) concentrations of 0, 1.0, 3.0, and 5.0 mg L-1, respectively. The Cd in pea sprouts was continuously extracted with 100 °C distilled water, 60% ethanol, 6% acetic acid, and simulated gastric juice. It was observed that highest amount of Cd (48.65-58.87%) was found in the extraction of roots with 6% acetic acid, followed by 100 °C distilled water (28.68-37.61%). While in stems, most of the Cd (70.73-85.39%) was extracted by 6% acetic acid. The recovery rate of the sequential chemical extraction technique employed in this experiment was between 93 and 106%. Compared with traditional methods, this study has its development potential in two aspects. First, it can determine which steps of sequential extractions of heavy metals in plants are the most harmful to humans. Secondly, corresponding measures can be taken to reduce heavy metals in vegetables used daily, such as soaking edible vegetables in vinegar for a short time. Novelty statement: In this study, a novel extraction and safety evaluation method for heavy metals based on different functions of plants was proposed, and an edible plant (pea) was used as the research material to explore the feasibility of the novel method. Compared with the commonly used extraction methods, the novel method is more reasonable and has greater development potential.

Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) Method Validation: Determination of Heavy Metals in Dietary Supplements

Dietary supplements may contain heavy metals with the property of bioaccumulation in humans. The aim of this research was to validate and apply two analytical methods to determine Pb, As, Cr, and Hg in dietary supplements by Total Reflection X-ray Fluorescence Spectroscopy (TXRF). Methods validation was conducted through a multivariate analysis using a central composite design (CCD) and a desirability function. Critical values for each study variable were established. The TXRF_DS_1 method was proposed for Pb, As, and Cr determinations, while the TXRF_DS_2 was established for Hg analysis. The digestion method with an acid mixture (HNO3 + HCl + H2O2) was used to break down the organic material of dietary supplements. A solution of 10 μg L−1 Ga was used as an internal standard. Excellent analytical performance was obtained as LODs of 0.59, 0.41, 0.57, and 0.75 μg L−1 and LOQs of 1.95, 1.35, 1.90, and 2.50 μgL −1 for Pb, As, Cr, and Hg, respectively. Calibration curves showed a good linearity for all elements (R2>0.999). Excellent accuracy and precision in measurements (% RSD) was achieved. The real and spiked samples analysis demonstrated the applicability of the TXRF technique (percentage recovery 91–108%). Besides, two samples were analyzed in a comparison study between the TXRF_DS_1 method and the ICP-OES method. The results obtained showed good agreement between both techniques. The TXRF technique allows the analysis of toxic heavy metals in dietary supplements, which are marketed in a wide variety of presentations.

A systematic review on the skin whitening products and their ingredients for safety, health risk, and the halal status

BACKGROUND

Skin-whitening products are in the high trend of demand for skin beautifying and lightening. Sources of ingredients for cosmetics could be natural, semi-synthetic, and synthetic that may affect the halal status of a product. The lack of scientific evidence on the safety and risks of such ingredients is a major concern to many consumers.

OBJECTIVE

This review paper aimed to shed light on the skin-whitening ingredients and their issues related to safety, health risk, and halal status.

METHODOLOGY

Based on the reviews scientific publications published from January 2015 to July 2020 using Web of Science and Scopus engines.

FINDINGS

Based on the review, most of the common ingredients in the skin-whitening products are originated from plants, animals, microbes, and heavy metals. Health risk of the ingredients was evaluated based on the usage, chronic or acute adverse effect, frequency of incidence, and the hazardous chemical contents of a halal cosmetics. The halal status of the ingredients was investigated based on the sources of origin, safety evaluation, and associated health risk of the ingredients.

ORIGINALITY

This review shows that ingredients play a vital role in the halal status decision-making of a cosmetic product. Therefore, the categories of Halal-Safe, Haram-Prohibited, and Critical-Need further evaluation were suggested to integrate the sources of ingredients with safety.

Determination of Some Common Heavy Metals and Radionuclides in Some Medicinal Herbs Using ICP-MS/MS

Medicinal herbs are the ancient, traditional way of treating many diseases and are now considered the first natural source of pharmaceutical active ingredients. Therefore, it is very important to focus on the hygiene of these plants so as to make sure they are safe for consumption. This work aimed to monitor the common heavy and radioactive elements in some commonly used herbs: anise, chamomile, clover, cumin, coriander, fennel, roselle, rosemary, sage, and thyme. A total of 12 elements were measured including 2 radionuclides, Al, As, Cd, Hg, Co, Cr, Ni, Pb, Sr, Th, U, and V. Heavy metals are ecologically and biologically important, and may be involved in some health disorder symptoms within the human body. Samples were digested with a microwave digester and measurements were completed with ICP-MS/MS in Helium mode to increase sensitivity, lower the background, and avoid interferences. Method validation and verification were performed through the spiking process at 2.0 µg/kg level, and then RSD, LOD, and LOQ were calculated. Recoveries ranged from 93-103% for all elements and RSD% from 2.8-9.6%. Hg and Th were not detected in all samples, while U was detected in some sample of anise, rosemary, sage, and thyme, and ranged from 0.018-0.048 mg/kg. As was detected in anise, fennel, roselle, and rosemary, and ranged from 0.0.031-5.88 mg/kg. Al, Cd, Co, Cr, Ni, Pb, Sr, and V were detected in most samples of all herbs, and ranged from 3.88-17.80, 0.122-0.654, 0.019-0.851, 0.344-2.91, 1.872-5.82, 0.120-12.56, 0.128-0.844, and 0.083-0.912 mg/kg, respectively.