Comparison of mercury levels in various tissues of albino and pigmented mice treated with two different brands of mercury skin-lightening creams

Appraisal and health risk assessment of potential toxic element in fruits and vegetables from three markets in Anambra state, Nigeria

The influence of anthropogenic activities has led to increase of potential toxic elements (PTEs) present in plant-based food sources, even in trace amounts; thus, it is known to pose a threat to human health over an extended period. The concentration levels of PTEs (Pb, Cu, Zn, Cd, Co and Ni) in soils and fruits and vegetables from three markets (Atani, Omor and Eke Awka) in Anambra state, Southeastern Nigeria were quantified and assessed using Atomic Absorption Spectrophotometer (AAS) instrument. The result of PTE (mg/kg) studied was in the order Zn > Cu > Pb > Ni > Co > Cd with the highest value for Zn (13.61 mg/kg) recorded in soil sample at Omor market. The mean concentrations of PTEs in soil of both evaluated studied areas were lower than the WHO permissible limits for PTEs in soil. Among the fruits and vegetables, Bitter leaf had highest PTE from Eke Awka followed by banana, fluted pumpkin, water leaf and onion. Fluted pumpkin had the highest PTE content from Omor followed by watermelon, water leaf, onion and cucumber, while water leaf had the highest metal concentration from Atani followed by bitter leaf, fluted pumpkin, cucumber, lettuce and carrot. Health risk assessment showed that hazard index (HI) in decreasing order was Eke – Awka market > Omor market > Atani market across all fruits and vegetables, as adverse health effect is not expected. The present study recommends containment measures of potential toxic elements in soils and fruits/vegetables to prevent excessive accumulation in food value chain.

Experimental Calculations of Metals Content in Skin-Whitening Creams and Theoretical Investigation for Their Biological Effect Against Tyrosinase Enzyme

The demand for skin-whitening creams (SWCs) has increased rapidly worldwide due to sharp rise in product advertisements in the media and the growing awareness. Metals are present either as impurities or added intentionally in creams and may have toxic effects on users. The present study was carried out to determine the content of metals such as mercury (Hg), cadmium (Cd), lead (Pb), arsenic (As), chromium (Cr), nickel (Ni), cobalt (Co), copper (Cu), zinc (Zn), and iron (Fe) in fifteen skin-whitening creams marketed at local shops in Islamabad, Pakistan. The concentrations of metals were analyzed by inductive coupled plasma-optical emission spectrometer (ICP-OES) after digestion with a mixture of HNO₃, HCl, and H₂O₂. The skin-whitening creams were found to have metal concentrations in parts per million (ppm) in the following range: Hg (1.0-18,210 ppm), Co (0.1992-1.9931 ppm), Cr (1.0453-2.7455 ppm), Cu (0.6987-0.1997 ppm), Fe (8.8868-28.6213 ppm), Ni (0.7487-1.5958 ppm), Pb (0.2997-4.7287 ppm), and Zn (7819.2-39,696.7 ppm). As and Cd were not detected in any of the fifteen skin-whitening creams. Only one cream (L'Oréal Paris White Perfect) was found in safe limits defined by the Food and Drug Administration for cosmetics. In order to elucidate the mechanism of lower production of melanin in presence of heavy metals, a molecular docking study was carried out by using Molecular Operating Environment (MOE) software. A good correlation was observed between experimental findings and molecular docking studies.

Production and characterization of crude laccase from Irpex sp. JS7 that decolorizes synthetic and natural melanin

The JS7 strain, isolated from an old forest tree, produces extracellular enzymes that decolorize synthetic and natural melanin from human hair. Phylogenetic analysis based on the internal transcribed spacer (ITS) sequence indicated that JS7 belongs to the genus Irpex. The JS7 strain has laccase activity while it lacks manganese and lignin peroxidase activity, which suggests that the JS7 strain melanin decolorization activity originated from laccase. Laccase production from the Irpex sp. JS7 improved three-fold in the presence of veratryl alcohol, compared to without an inducer. The optimum pH and temperature for melanin decolorization were 7.5 and 40 °C, respectively. The crude enzyme half-life at 25 °C was about 100 days, and it had high storage stability. The melanin decolorization reaction rate by the crude enzyme conformed to typical enzyme kinetic principles. In the presence of syringaldehyde as a redox mediator, the melanin decolorization rate was 75% within 5 days, similar to the decolorization percentage obtained using the enzyme alone. Based on these results, the Irpex sp. JS7 enzyme is suitable for use in melanin decolorization by whitening agents in the cosmetics industry.

Skin-lightening practices behind the veil: An epidemiological study among Saudi women

BACKGROUND

Women are adopting skin-lightening practices worldwide in an attempt to enhance their skin tone. The reasons and beliefs behind such practices vary from culture to culture. Scarce data are available for this phenomenon among Saudi women. We carried out this study to determine the practices, reasons, and correlates of skin-lightening practices among women in the northern region of Saudi Arabia.

METHOD

Using nonprobability convenient sampling, an analytical cross-sectional study was carried out among women attending two multispecialty hospitals in the Al-Jouf region. A prevalidated, self-administered questionnaire containing 35 items about demographic characteristics, skin-lightening practices, knowledge of skin-lightening products (SLPs), reasons, and perceptions about lighter skin tone was used to collect data.

RESULTS

Among 605 sampled women, usage of skin-lightening practices was found in 382 participants (63.1%). All participants had relatively lighter skin. Skin type and education affected skin-lightening practices significantly (P values = 0.002 and 0.012, respectively). The prevalent reason for using SLPs was cosmetic (66%). One-third of users faced side effects from these products. The SLP users believed that lighter skin tone plays a role in self-esteem, perception of beauty, social class, marriage, and employment opportunities (P values < 0.01) as compared to nonusers. Media was found to influence the use of SLPs (P values < 0.001).

CONCLUSION

Skin-lightening practices are prevalent among Saudi women. Such practices are reinforced by a belief that fairer skin is associated with beauty, self-esteem, and financial and social advantages. A public health educational campaign is needed to decrease the usage of SLPs.

Concentration of heavy metals in vegetables and potential health risk assessment in China

Food safety is an important issue in the world. This study assessed the health risk for the Chinese public when consuming vegetables grown in China, based on 1335 data records from 220 published papers during 2007-2016. The results showed that the average of Pb, Cd, and Hg concentration in vegetables was 0.106, 0.041, and 0.008 mg/kg, which were lower than the maximum allowable concentrations, respectively. Leaf vegetables contained higher heavy metals than root vegetables and fruit vegetables. On a provincial scale, the highest Pb, Cd, and Hg concentrations in vegetables were determined by those in soil and atmosphere. The total health risk index showed that people in Guizhou, Yunnan, Guangxi, Hunan, Guangdong, Hubei provinces in southern China, and Liaoning Province in northeast China, faced a high risk of Pb, Cd, and Hg when consuming vegetables.

Transfer of mercury and phenol derivatives across the placenta of Baltic grey seals (Halichoerus grypus grypus)

The placenta is an intermediary organ between the female and the developing foetus. Some chemical substances, including the most harmful ones, exhibit the ability to accumulate in or penetrate through the placenta. The aim of the study was to determine the role of the placenta of the Baltic grey seal (Halichoerus grypus grypus) in the transfer of endocrine disrupting compounds (EDCs) - (bisphenol A, 4-tert- octylphenol, 4- nonylphenol), as well as total and organic mercury. 30 placentas were collected from grey seals pupping under human care at the Hel Marine Station in the years 2007-2016. The assays were conducted using the technique of high-preformance liquid chromatography (phenol derivatives) and atomic absorption spectrometry (mercury and selenium). A measurable level of EDCs was indicated in the placentas of grey seals. It was established that the inorganic Hg form was accumulated in the placenta, and that its concentrations were an order of magnitude higher than the concentrations of the organic form, which penetrated to the foetus. Similar observations were made for phenol derivatives - bisphenol A, 4-tert- octylphenol and 4-nonylphenol. For this compound group the placenta was a barrier, but the properties of phenol derivatives suggest the possibility of their penetration through this organ.

Determination of heavy metals in skin-whitening cosmetics using microwave digestion and inductively coupled plasma atomic emission spectrometry

In this study, the determination of noxious heavy metals, cadmium (Cd), bismuth (Bi), mercury (Hg), titanium (Ti), lead (Pb) and metalloid arsenic (As) in skin-whitening cosmetics were examined using microwave digestion and inductively coupled plasma atomic emission spectrometry method. A complete digestion of cosmetics samples was achieved using a mixture of hydrofluoric acid/hydrogen peroxide/nitric acid. The quantification of the target compounds was done by standard addition method. The excellent quality parameters for instance, detection limits, As (4.6 ppb), Bi (7.9 ppb), Cd (0.45 ppb), Hg (3.3 ppb), Pb (3.8 ppb), Ti (4.3 ppb), linearity (r2 > 0.999) and run-to-run and day-to-day precisions with relative standard deviations <3% were obtained. The recovery rates for standard reference materials were found between 90 and 105%. The average concentration of heavy metals in cosmetics samples were in the range of 1.0-12.3 (μg g-1, As), 33-7097 (μg g-1, Bi), 0.20-0.6 (μg g-1, Cd), 0.70-2700 (μg g-1, Hg), 1.20-143 (μg g-1, Pb) and 2.0-1650 (μg g-1, Ti).

Mercury contamination in facial skin lightening creams and its health risks to user

This study aims to determine concentrations of mercury in facial skin lightening cream according to different price categories (category I: <RM29.99, category II: RM30.00-RM59.99, category III: RM60.00-RM99.99 and category IV: ≥RM100.00) and their potential health risks to users. Prices of skin lightening creams were determined during a preliminary market survey. Thereafter, twenty samples were purchased from various locations such as cosmetic stalls, beauty shops, pharmacies and street vendors based on their stratified price categories. Samples were extracted using microwave digester and analyzed using cold vapor atomic absorption spectrometry (CV-AAS). Non-carcinogenic chronic health risks for application of facial skin lightening cream were calculated using Dermal Absorption Dose (DAD) and Hazard Quotient (HQ). Concentrations of mercury in samples were less than the United States Food and Drug Administration (USFDA) permitted trace levels (<1 ppm) except for one sample from category III which was manufactured in China. Concentrations of mercury in facial skin lightening creams ranged from not detected to 1.13 mg kg^-1. There was no significant association between concentrations of mercury with price categories (p = 0.12). There was no significant non-carcinogenic health risk due to daily application of the facial skin lightening creams based on assumption of 30 years exposure period (HQ < 1).

Evaluation of Ubtan - A traditional indian skin care formulation

ETHNOPHARMACOLOGICAL RELEVANCE

'Ubtan' is a traditional herbal formulation in the Indian system of medicine being used in India and its subcontinent for a long time. Several commercial skin care formulations are marketed throughout this region as the name of Ubtan. Therefore, it is worthwhile to evaluate Ubtan in respect of its efficacy as skin care formulation.

AIM OF THE STUDY

The present study was designed for the preparation of Ubtan and standardization through the chromatographic techniques by using suitable phyto-markers. Further, its antioxidant, sun protection factor (SPF) and anti-tyrosinase potential have been explored.

MATERIALS AND METHODS

Four in-house formulations (UF-1, UF-2, UF-3 and UF-4) were prepared by mixing a varied quantity of each powdered plants, i.e. turmeric (Curcuma longa L.), Chickpea (Cicer arietinum L.) and sandalwood (Santalum album L.). Optimization of the formulations was made by evaluating its biological activity through in vitro assay. Evaluation of physicochemical properties of the optimized formulation (UF-1) has been carried out by analysis of pH, flow properties and stability. Moreover, RP-HPLC (reverse phase - high performance liquid chromatography) and HPTLC (high performance thin layer chromatography) standardization of UF-1 was performed for its quantitative and qualitative analysis.

RESULTS

Ubtan formulations (UF-1to UF-4) showed free radical scavenging and ferric reducing potential. It may be due to its high phenolic and flavonoid content. Statistically, significant Pearson's correlation (r) was confirmed the positive correlation between phenolic content and SPF of the formulations. The tyrosinase inhibition study indicated that the formulations showed both diphenolase and monophenolase inhibitory activity. Among four formulations, UF-1 showed notable biological activity (p<0.05). The content of curcumin and ascorbic acid was found to be 1.6% and 2.1% w/w respectively in UF-1 through RP-HPLC estimation. Physiochemical properties of the UF-1 exhibited good flow rate and aqueous solubility. From the stability studies, it can be anticipated that the UF-1 was stable at 40°C for longer periods. Microbial load count and heavy metal content (lead-Pb, arsenic-As, mercury-Hg and cadmium-Cd) of the formulation was also within the permissible limit of a pharmacopeial standard.

CONCLUSION

This scientific exploration helps to set the quality and safety standard of traditional cosmetic formulation, Ubtan and its further use as an herbal skin care product.

The importance of evaluating metal exposure and predicting human health risks in urban-periurban environments influenced by emerging industry

The human population boom, urbanization and rapid industrialization have either directly or indirectly resulted in the serious environmental toxification of the soil-food web by metal exposure from anthropogenic sources in most of the developing industrialized world. The present study was conducted to analyze concentrations of Cd, Cr, Cu, Mn, Ni, Pb, and Zn in soil and vegetables in the urban-periurban areas influenced by emerging industry. Vegetables and their corresponding soil samples were collected and analyzed for heavy metals contents from six random sites. According to the results, the potential health risks from metals to the local communities were assessed by following the methodology described by the US-EPA. In general, the total non-carcinogenic risks were shown to be less than the limits set by the US-EPA. However, the potential risk of developing carcinogenicity in humans over a lifetime of exposure could be increased through the dietary intake of Cd, Cr and Ni. In some cases, Pb was also marginally higher than the safe level. It was concluded that some effective remedial approaches should be adopted to mitigate the risks of Cd, Cr, Ni and Pb in the study area because these metal levels have exceeded the safe limits for human health. However, new studies on gastrointestinal bioaccessibility in human are required to heighten our understanding about metals exposure and health risk assessment.

Direct determination of mercury in cosmetic samples by isotope dilution inductively coupled plasma mass spectrometry after dissolution with formic acid

A new method was proposed for the accurate determination of mercury in cosmetic samples based on isotopic dilution (ID)-photochemical vapor generation (PVG)-inductively coupled plasma mass spectrometry (ICP MS) measurement. Cosmetic samples were directly dissolved in formic acid solution and subsequently subjected to PVG for the reduction of mercury into vapor species following by ICP MS detection. Therefore, the risks of analyte contamination and loss were avoided. Highly enriched (201)Hg isotopic spike is added to cosmetics and the isotope ratios of (201)Hg/(202)Hg were measured for the quantitation of mercury. With ID calibration, the influences originating from sample matrixes for the determination of mercury in cosmetic samples have been efficiently eliminated. The effects of several experimental parameters, such as the concentration of the formic acid, and the flow rates of carrier gas and sample were investigated. The method provided good reproducibility and the detection limits were found to be 0.6 pg mL(-1). Finally, the developed method was successfully applied for the determination of mercury in six cosmetic samples and a spike test was performed to verify the accuracy of the method.

Spectrometric analysis of mercury content in 549 skin-lightening products: is mercury toxicity a hidden global health hazard?

BACKGROUND

Cosmetic skin lightening is practiced worldwide. Mercury is a well-documented melanotoxin added to some lightening products. However, mercury can cause many dermatologic, renal, and neurologic problems. The Food and Drug Administration limits the amount of mercury in cosmetic products to trace amounts, 1 ppm.

OBJECTIVE

The objective of this study was to quantitatively evaluate a large international sample of lightening products for mercury content, focusing on products available to US consumers either online or in stores.

METHODS

A total of 549 skin-lightening products, manufactured in 32 countries, were purchased online in the United States, Taiwan, and Japan and in stores in the United States, China, Taiwan, Thailand, Japan, and Sri Lanka. Cosmetics were screened for mercury content above 200 ppm using a low-cost portable x-ray fluorescence spectrometer.

RESULTS

Of the 549 tested products, 6.0% (n = 33) contained mercury above 1000 ppm. In all, 45% of mercury-containing samples contained mercury in excess of 10,000 ppm. Of lightening products purchased in the United States, 3.3% were found to contain mercury in excess of 1000 ppm.

LIMITATIONS

Our study did not evaluate creams for other melanosuppressive ingredients. Only 1 sample of each product was tested.

CONCLUSION

Our study confirms the national and global presence of mercury in skin-lightening products.

Human health risk assessment of heavy metals in soil-vegetable system: a multi-medium analysis

Vegetable fields near villages in China are suffering increasing heavy metal damages from various pollution sources including agriculture, traffic, mining and Chinese typical local private family-sized industry. 268 vegetable samples which included rape, celery, cabbages, carrots, asparagus lettuces, cowpeas, tomatoes and cayenne pepper and their corresponding soils in three economically developed areas of Zhejiang Province, China were collected, and the concentrations of five heavy metals (Pb, Cd, Cr, Hg and As) in all the samples were determined. The health risk assessment methods developed by the United States Environmental Protection Agency (US EPA) were employed to explore the potential health hazards of heavy metals in soils growing vegetables. Results showed that heavy metal contaminations in investigated vegetables and corresponding soils were significant. Pollution levels varied with metals and vegetable types. The highest mean soil concentrations of heavy metals were 70.36 mg kg(-1) Pb, 47.49 mg kg(-1) Cr, 13.51 mg kg(-1) As, 0.73 mg kg(-1) for Cd and 0.67 mg kg(-1) Hg, respectively, while the metal concentrations in vegetables and corresponding soils were poorly correlated. The health risk assessment results indicated that diet dominated the exposure pathways, so heavy metals in soil samples might cause potential harm through food-chain transfer. The total non-cancer and cancer risk results indicated that the investigated arable fields near industrial and waste mining sites were unsuitable for growing leaf and root vegetables in view of the risk of elevated intakes of heavy metals adversely affecting food safety for local residents. Chromium and Pb were the primary heavy metals posing non-cancer risks while Cd caused the greatest cancer risk. It was concluded that more effective controls should be focused on Cd and Cr to reduce pollution in this study area.

Mercury transfer during pregnancy and breastfeeding: hair mercury concentrations as biomarker

Hair mercury (HHg) concentration is a biomarker of exposure that is widely used to assess environmental contamination by fish methylmercury and neurodevelopment in children. In the Rio Madeira basin (Brazilian Amazon), total HHg concentrations in 649 mother-infant pairs were measured at birth (prenatal exposure) and after 6 months of exclusive breastfeeding; these mother-infant pairs were from high fish-eating communities (urban, n = 232; rural, n = 35; and Riverine, n = 262) and low fish-eating tin-miner settlers (n = 120). Differences in kinetics were seen between Hg exposure from fish consumption and environmental exposure to a tin-ore mining environment. Overall maternal HHg concentrations (at childbirth and after 6 months of lactation) were higher than those of infant HHg. However, the relative change in HHg after 6 months of lactation showed that mothers decreased HHg while infants increased HHg. The relative change showed a consistently higher increase for girls than boys with a statistical significance only in high fish-eating mothers. The correlation coefficients between maternal and newborn hair were high and statistically significant for mothers living in urban (r = 0.66, p < 0.001), rural (r = 0.89, p < 0.001), and Riverine (r = 0.89, p < 0.001) communities not for tin miner settlers (r = 0.07, p = 0.427). After 6 months of exclusive breastfeeding, correlation coefficients showed high correlation coefficients and statistical significance for all groups (urban, r = 0.73, p < 0.001; rural, r = 0.88, p < 0.001; Riverine, r = 0.91, p < 0.001) except for Tin miners (r = -0.07, p = 0.428). A linear model analysis was used to assess the longitudinal associations of maternal total HHg and total HHg at birth (0 days) and 6 months of age in exclusively breastfed infants. Regression analysis significantly predicted HHg in newborn from maternal HHg for high fish-eating maternal-infant pairs.

CONCLUSION

The concentration of mercury accumulated in newborn tissues (in utero and during breastfeeding) relevant to both, maternal sources and infant exposure, can be reliably assessed from maternal hair.

Application of solid phase extraction on multiwalled carbon nanotubes of some heavy metal ions to analysis of skin whitening cosmetics using ICP-AES

A novel and highly sensitive method for the determination of some heavy metals in skin whitening cosmetics creams using multiwalled carbon nanotubes MWCNTs as solid phase extraction sorbent for the preconcentration of these heavy metals prior to their determination by inductively coupled plasma atomic emission spectrometry is described. Different practical parameters have been thoroughly investigated and the optimum experimental conditions were employed. The developed method was then applied for the determination of arsenic, bismuth, cadmium, mercury, lead and titanium in samples of skin whitening cosmetics. The detection limits under these conditions for As, Bi, Cd, Pb, Hg and Ti were 2.4, 4.08, 0.3, 2.1, 1.8, and 1.8 ng·mL-1, respectively. The relative standard deviations (RSDs) were found to be less than 2.0%. For validation, a certified reference material of NIST SRM 1570a spinach leaves was analyzed and the determined values were in good agreement with the certified values. The recoveries for spiked samples were found to be in the range of 89.6-104.4%.

Skin-lightening practice among women living in Jordan: prevalence, determinants, and user's awareness

BACKGROUND

The use and misuse of skin-lightening products among women living in Arab communities have not been documented previously. This study investigates the determinants, the prevalence and users awareness associated with the use and misuse of skin-lightening products among women living in Jordan.

METHOD

Female customers arriving at selected pharmacy stores were randomly asked to complete a questionnaire.

RESULTS

A total of 318 women completed the questionnaire, of which 60.7% reported the use of skin-lightening products. Users included women from different age and economic groups. Main reasons for use were preference of lighter skin tone, the treatment of hyperpigmentary disorders or both. More than a third of the users were not aware of the potential side effects of these products. A significantly larger proportion of skin-lightening product users believed that lighter skin tone plays a role in self-esteem, perception of beauty and youth, marriage and employment opportunities when compared with nonusers.

CONCLUSION

Skin lightening is a common practice among women living in Jordan. It is reinforced by the association of lighter skin tone with a number of perceived benefits including perception of beauty, job and marriage opportunity. User's awareness regarding the safety of skin-lightening products and instructions for proper use are important considerations when developing interventions to control the misuse of these products.

Accumulation of mercury in ovaries of mice after the application of skin-lightening creams

Skin-lightening creams are being increasingly used by women in particular, worldwide in an attempt to whiten their skin. Men and older people use these creams to remove age spots or other pigmentation disorders. Several studies have reported the presence of high mercury levels in skin-lightening cream. Women, especially pregnant and nursing mothers, who use these creams are at risk of mercury toxicity because long-term exposure can cause permanent neurological damage, nephrological disorders, fertility problems, and birth defects. Early exposure usually has no clinical symptoms. Mercury levels were measured in a total of 49 ovary tissue samples. The mean mercury contents in the ovaries of non-treated mice (11.70 +/- 13.38 ng/g) were compared to mice treated with Rose skin-lightening cream samples (2,471.92 +/- 1,336.31 ng/g) and those treated with Fair & Lovely skin-lightening creams (58.47 +/- 39.51 ng/g). The mercury content in the ovary tissues increased with number of cream applications and were highest in the ovaries of mice treated twice a day with Fair & Lovely (87.79 +/- 26.20 ng/g) and once a day with Rose (3,515.61 +/- 1,099.78 ng/g). Our data indicate that dermal exposure to mercury can result in a significant accumulation in the ovaries of mice following the application of skin-lightening cream. This may cause alterations in reproductive behavior and contribute to infertility or ovarian failure. Of course, these results need to be confirmed by further research. Imported or locally made skin-lightening creams are widely available in Saudi market. It would be ideal to ban the sale of these creams but unfortunately, advertisements in the mass media presenting celebrities and beauty specialists make these products more popular. Alternatively, public health authorities should encourage more reliance on prescribed creams for the treatment of skin pigmentation problems.