Potential health consequences of applying mercury-containing skin-lightening creams during pregnancy and lactation periods

The Use of Over-the-Counter (OTC) Skin-Lightening Agents and Their Side Effects Among the Residents of Saudi Arabia: A Cross-Sectional Study

INTRODUCTION

Over-the-counter (OTC) skin-lightening agents are topical products in the form of lotions, creams, oils, soaps, and serums designed to alter skin pigmentation primarily for cosmetic purposes. The growing misuse and overuse of these products has become a serious public health concern due to their potential adverse effects on human health and their quality of life.

METHODS

This study was cross-sectional in nature, adopting a convenience sampling technique utilizing data from a sample of 408 residents of Arar, Northern Saudi Arabia. The participants completed online questionnaires, distributed through social media means like Telegram, WhatsApp, and Facebook ensuring anonymity. Data was analyzed using SPSS Version 27 to obtain important insights.

RESULTS

The sample of the study had a predominance of females 304 (74.5%) while only 104 (25.5%) were males. A substantial proportion of 170 (41.7%) of the participants were aged between 20 and 35 years with more than half (229 (56.2%)) being single and the majority (266 (65.2%)) having university and above level of education. More than half (259 (63.5%)) of them indicated that they had bought skin-lightening products without a doctor's prescription. Twenty-eight (10.8%) of the participants had been diagnosed with a condition that increased skin pigmentation before with a substantial proportion (11 (39.3%)) noting that the product contained hydroquinone cream ingredients. The overall prevalence of OTC skin-lightening agents among the participants of Arar, Northern Saudi Arabia was 63.5% (259/408). The study found a significantly high prevalence of use of OTC skin-lightening agents among participants aged 20-35 years (87 (71.3%)) (p=0.031) as well as those who had a university level of education and above (129 (71.3%)) (p=0.001). The findings show that 39 (40.6%) of the female respondents and eight (30.8%) of the male participants experienced adverse effects associated with irritation and redness.

CONCLUSION

Overall, the study found a considerably high prevalence of the use of OTC skin-lightening agents among the participants of Arar, Northern Saudi Arabia. The use of OTC skin-lightening agents was significantly greater among female participants than male participants. The commonly used products contained hydroquinone cream ingredients, which presented adverse effects and complications associated with irritation, redness, and darkening of the skin. It is imperative to launch targeted public awareness campaigns to educate the community, especially women, about the risks associated with OTC skin-lightening agents, promote safer alternatives, and advocate for stricter regulation and control over the sale and distribution of skin-lightening products containing harmful ingredients.

Quality assessment of hydroquinone, mercury, and arsenic in skin-lightening cosmetics marketed in Ilorin, Nigeria

Hydroquinone, Mercury (Hg), and Arsenic (As) are hazardous to health upon long-term exposure. Hydroquinone, Hg, and As were analysed in skin-lightening cosmetics randomly purchased from different cosmetic outlets within the Ilorin metropolis, Nigeria. The amount of hydroquinone in the samples was determined using a UV-spectrophotometry method at 290 nm. Hg and As were quantified using atomic absorption spectrophotometry (AAS). UV-spectrophotometry method validation showed excellent linearity (r2 = 0.9993), with limits of detection (0.75 µg/mL), limits of quantification (2.28 µg/mL), relative standard deviation (0.01-0.35%), and recovery (95.85-103.56%) in the concentration range of 5-50 µg/mL. Similarly, r2, LOD, and LOQ for Hg and As were 0.9983 and 0.9991, (0.5 and 1.0 µg/L) and 1.65 and 3.3 µg/L) respectively. All the samples contained hydroquinone, Hg and As in varying amounts. The amounts of hydroquinone, Hg and As present were in the ranges of 1.9-3.3%, 0.08-2.52 µg/g and 0.07-5.30 µg/g respectively. Only three of the analysed samples contained hydroquinone within the permissible limit of 2.0% w/w in cosmetic products. All the samples analysed contained mercury and arsenic in varying amounts. The need to periodically monitor the levels of hydroquinone, mercury, and arsenic in skin-lightening cosmetics marketed in Nigeria is recommended.

Determinants affecting the blood mercury levels of preschool children in Shanghai, China: A cross-sectional study

Infants and children are vulnerable to mercury (Hg)-induced toxicity, which has detrimental effects on their neurological development. This study measured blood Hg levels (BMLs) and identified potential factors influencing BMLs, including demographic and socioeconomic factors, lifestyle, and daily dietary habits, among 0 to 7-year-old children in Shanghai. Our study recruited 1474 participants, comprising 784 boys and 690 girls. Basic demographic and lifestyle information were obtained and blood Hg were analyzed using the Direct Mercury Analyzer 80. The blood Hg concentrations of children in Shanghai ranged from 0.01 to 17.20 μg/L, with a median concentration of 1.34 μg/L. Older age, higher familial socioeconomic status, higher residential floors, and a higher frequency of consuming aquatic products, rice, vegetables, and formula milk were identified as risk factors. Other potential influencing factors including the mother's reproductive history (gravidity and parity), smoking (passive smoking), supplementation of fish oil and calcium need to be further investigated. These findings can be useful in establishing appropriate interventions to prevent children's high blood Hg concentrations in Shanghai and other similar metropolitan cities.

A Cross-Sectional Study of the Knowledge, Practice, and Attitude Towards Skin-Lightening Products Among the General Population in the Western Region of Saudi Arabia

Introduction Skin bleaching is a growing phenomenon worldwide and is becoming an increasing problem. Several skin-lightening products (SLPs) containing mercury, hydroquinone, and corticosteroids have impacted serious dermatological, nephrological, and neurological side effects. There is relatively little regulation, and the products are easily accessible and inexpensive. Justifications and beliefs for the use of these products vary from culture to culture, and there is little previous research on the use and abuse of skin-lightening cosmetics among Saudi women. This study examines the knowledge, attitudes, and practices of the public in the western region of Saudi Arabia regarding SLPs to understand the situation better. Methodology An observational, cross-sectional, questionnaire-based study was conducted over two months between July and August 2022. A 29-question survey was used to collect data from the general population. The study included all women residing in the western region of Saudi Arabia. Non-Arabic speakers were excluded. RStudio (R version 4.1.1) was used to analyze the data. Results A total of 409 participants were included in this study; In general, 146 (35.7%) of the participants said they had ever used an SLP. More than two-thirds (67.1%) had been using them for less than a year. In terms of the most common site of SLPs application, women reported applying the products to the skin of their face (74.7%), elbows (47.3%), and knees (46.6%). Use of SLPs differed significantly across participants' ages, with the proportion of SLP users in the 20-30 age category significantly higher than non-users (50.7% vs. 36.9%, p=0.017), and non-users were more common than users within the age category >50 years. In addition, the proportion of SLP users relative to educational level was significantly higher among participants with a bachelor's degree than the proportion of non-users (69.2% vs. 54.0%, p = 0.009). Conclusions The results of this research show that Saudi women frequently utilize topical lightening products. Therefore, regulation and controlling the use of bleaching products is essential, as is educating women about the risks involved with this practice. The misuse of bleaching products should decline with greater awareness.

Self-Powered Photoelectrochemical Assay for Hg2+ Detection Based on g-C3N4-CdS-CuO Composites and Redox Cycle Signal Amplification Strategy

A highly sensitive self-powered photoelectrochemical (spPEC) sensing platform was constructed for Hg2+ determination based on the g-C3N4-CdS-CuO co-sensitized photoelectrode and a visible light-induced redox cycle for signal amplification. Through successively coating the single-layer g-C3N4, CdS, and CuO onto the surface of an electrode, the modified electrode exhibited significantly enhanced PEC activity. The microstructure of the material was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). However, the boost in photocurrent could be noticeably suppressed due to the consumption of hole-scavenging agents (reduced glutathione) by the added Hg2+. Under optimal conditions, we discovered that the photocurrent was linearly related to the Hg2+ concentration in the range of 5 pM–100 nM. The detection limit for Hg2+ was 0.84 pM. Moreover, the spPEC sensor demonstrated good performance for the detection of mercury ions in human urine and artificial saliva.

Effects of early and recent mercury and lead exposure on the neurodevelopment of children with elevated mercury and/or developmental delays during lactation: A follow-up study

This follow-up study of 82 children investigated the potential impact of early and recent exposure to mercury and lead on their neurodevelopmental performance at 5-8 years of age (2017-2018). Early exposure of these children to mercury, methylmercury, and lead was assessed during lactation at 3-12 months old, as well as their mother's exposure using measurements from a cross-sectional study (2011-2013). Only infants who failed to pass the neurodevelopment screening tools and/or had elevated mercury were included in this study. Urine and hair were sampled during the follow-up study to assess the children's recent exposure to mercury, methylmercury, and lead. Their cognitive performance and visual-motor integration were also measured using the Test of Non-Verbal Intelligence (TONI) and the Beery-Visual-Motor Integration (Beery VMI), respectively. The association between alterations in urinary porphyrins excretion and exposure to metals was analyzed and their influence on the children's neurodevelopment was explored. Linear regression models revealed a significant negative association between the infants' mercury exposure during lactation and the TONI Quotient (β = -0.298, 95%CI = -4.677, -0.414) and Beery VMI Age Equivalent scores at age 5-8 (β = -0.437, 95%CI = -6.383, -1.844). The mothers' blood methylmercury was inversely and significantly associated with their children's TONI Quotient (β = -0.231, 95%CI = -8.184, -0.331). In contrast, the children's Beery VMI Age Equivalent scores were positively and significantly associated with the hair methylmercury of the mothers (β = 0.214, 95%CI = 0.088, 3.899) and their infants (β = 0.256, 95%CI = 0.396, 4.488). These relationships suggest the presence of negative confounding that we did not take into account. Unlike mercury, there was some evidence that lead in breast milk had an inverse relationship with the children's visual-motor coordination skills. Our study did not show a clear association between children's recent exposure to metals and neurodevelopment. However, a significant inverse association was observed between the TONI Quotient and the interaction of hair methylmercury × ∑porphyrins (ß = -0.224, 95%CI = -0.86, -0.049), implying that porphyrins are a sensitive measure of low body-mercury burden. Although lead induced higher ∑porphyrins excretion in urine (β = 0.347, 95%CI = 0.107, 0.525), their interaction did not influence children's neurodevelopmental scores. The interactions between metals and porphyrins might provide insights into their potential contributory role in the pathogenesis associated with neurological disorders or other diseases. Despite the small sample size of the present study, its findings about the association between toxic metal exposure and the high risk of poor neurodevelopmental performance are worrying, particularly at an early age, and additional research is needed using larger sample sizes.

Mercury Exposure Associated with Use of Skin Lightening Products in Jamaica

BACKGROUND

Skin bleaching is a major health concern among Jamaicans. A common ingredient in skin lightening products is mercury. Mercury is a toxic substance that can cause damage to the gastrointestinal tract, nervous system and kidneys.

OBJECTIVE

The objectives of this study were to use different analytical techniques to measure mercury concentrations in popular skin lightening products used in Jamaica and to assess individual levels of mercury exposure based on product usage.

METHODS

Sixty skin lightening products were purchased from different vendors across various locations in Jamaica. Each product was initially screened for mercury using a portable handheld energy dispersive X-ray fluorescence (XRF) analyzer. In addition, 25 out of 60 products were further measured using cold vapor atomic absorption spectroscopy (CVAAS). Questionnaires were distributed to users of skin lightening products to determine their usage patterns.

RESULTS

Six products had mercury concentrations above the United States Food and Drug Administration (FDA) allowable limit of 1 ppm, of which three products contained alarmingly high concentrations (i.e. > 400 ppm). The majority of products (57 out of 60) had mercury concentrations below 10 ppm. The mercury concentrations in skin lightening products ranged from 0.05 ppm to 17,547 ppm. In our sample, 51% of women and 49% of men used skin products more than once per day.

CONCLUSIONS

On average, creams contained more mercury than lotions and soaps. Individuals who use skin lightening products in Jamaica may be at risk for high mercury exposure, as some popular products were found to have mercury concentrations above the allowable limit.

COMPETING INTERESTS

The authors declare no competing financial interests.

Inhibition of Tyrosinase by Mercury Chloride: Spectroscopic and Docking Studies

Inorganic mercury compounds have been used in skin-lightening products since ancient times. Although a previous study demonstrated that mercury impeded the transfer of Cu²⁺ to the apotyrosinase, the effect of mercury on tyrosinase is still unclear. In the present study, the mechanism of mercury chloride (HgCl₂) induced inactivation of tyrosinase was investigated for the first time. The IC₅₀ values were 29.97 and 77.93 μmol/L for monophenolase and diphenolase, respectively. A kinetic analysis revealed that HgCl₂ inhibited tyrosinase activity in an irreversible non-competitive manner. The strong intrinsic fluorescence quenching suggested that the formation of the HgCl₂-tyrosinase complex induced conformational changes of the enzyme, and HgCl₂ had only one single binding site or a single class of binding site on tyrosinase. The molecular docking and further experiments demonstrated that HgCl₂ bound to the amino residuals (His) in the catalytic center of tyrosinase. To our knowledge, these findings presented in this paper were the first evidence of the direct interactions between HgCl₂ and tyrosinase, which provided a deep understanding of the inhibition mechanism of mercury on tyrosinase.

Is skin bleaching a moral wrong? An African bioethical perspective

Focusing on black communities in Africa, in this paper, I attempt an African bioethico-aesthetic deconstruction of the falsehood in colorist definitions of beauty purveyed by the migration of non-surgical cosmetics to Africa. I provide a novel ethical evaluation of the act of skin bleaching using principles of the African ethic of communion. I argue that skin bleaching is morally wrong to the extent that it promotes disharmonious relations and false identity in the beauty industry in Africa. Drawing on scientific studies that link toxic ingredients in many skin-bleaching products to adverse health effects, I discuss the public health impact of bleaching cosmetics and other problems occasioned by their strategic expansion into African markets. I propose that there is an urgent need for a relational ethic of polycentric governance that would harmoniously regulate the production and distribution of cosmetic products across regions in order to avoid the exploitation of consumers in black African societies, while also protecting consumers' right to make informed choices through education.

Elevated blood mercury level has a non-linear association with infertility in U.S. women: Data from the NHANES 2013-2016

Mercury is a ubiquitous toxic heavy metal associated with an increased risk of female infertility; however, the evidence supporting this is limited and controversial. We aimed to explore the relationship between the total blood mercury and infertility in 1796 selected participants from the National Health and Nutrition Examination Survey (NHANES) (2013-2016). We found no significant association between mercury and infertility based on a fully-adjusted model (OR 1.04; 95 % CI 0.91, 1.19), and the results remained robust in a series of sensitive analysis. However, a non-linear relationship was detected. By a two-piecewise linear regression model and recursive algorithm, we identified an inflection point of 5.278 μg/L, when blood mercury was >5.278 μg/L, a 1-unit increase in mercury (log2) was associated with 157 % greater adjusted odds of infertility (OR 2.57; 95 % CI 1.12, 5.87). Our findings provide new insights to advance the research of the link between mercury and infertility.

Skin lightening products' violations in Europe: An analysis of the rapid alert system for dangerous non-food products 2005-2018

BACKGROUND

Skin lightening products containing dangerous levels of chemicals pose a serious health concern for consumers. However, to date, the extent of these products in Europe has not been extensively studied. The aim of this study was to determine whether harmful skin lightening products are available for sale in Europe and what violations exist regarding their composition.

MATERIALS AND METHODS

We queried the Rapex database, which is the Rapid Alert System for dangerous non-food products among 31 European countries, to identify skin lightening cosmetics reported between 2005 and 2018, and presented a detailed summary of these notifications.

RESULTS

In the years 2005-2018, of all violations regarding cosmetics, 26.3% concerned skin lightening products. In the database, 266 reports on skin lightening products were identified. Most of the notifications came from Germany (17.29%), France (17.29%), Portugal (15.41%), and the United Kingdom (11.65%). The majority of the registered products originated from non-European countries, mainly the Côte d'Ivoire (29.70%). The major reason for the violation was the content of hydroquinone, mercury, or clobetasol propionate.

CONCLUSIONS

Hazardous skin lightening products that are not in line with European cosmetics legislation are available on the European market. Most of the products are imported. The main risk associated with these products is the content of hydroquinone, mercury, and clobetasol propionate. It is important to bear in mind that this study focuses on the Rapex system and other sources of information may exist. Based on our findings, a more comprehensive evaluation by international authorities is justified.

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.

Skin Bleaching Among African and Afro-Caribbean Women in New York City: Primary Findings from a P30 Pilot Study

INTRODUCTION

The application of skin bleaching products to inhibit melanogenesis is a common practice within the African diaspora. Despite the adverse health effects of skin bleaching, rigorous studies investigating skin bleaching behavior among these populations in the United States are limited. In our P30 pilot study, we explored predictors of skin bleaching practice intensity among African and Afro-Caribbean women.

METHODS

In collaboration with our Community Engagement Core, we conducted a cross-sectional study to investigate the relationship between demographic and psychosocial predictors and skin-bleaching-related practice patterns among African and Afro-Caribbean women in New York City.

RESULTS

Among the 76 participants recruited, the median age at the initiation of skin bleaching was 19.5 (16-25) years, yielding a median duration of 13.5 (6-23) years. Although pregnant women were not actively recruited for the study, 13.2% (n = 10) of the participants used skin bleaching products while pregnant or possibly breastfeeding. Nativeness and education were associated with various components of skin bleaching practice intensity, including duration of skin bleaching, daily use of products, and bleaching of the entire body. Participants' perceived skin-color-related quality of life was not associated with skin bleaching practice intensity.

CONCLUSION

Skin bleaching is a habitual practice that likely requires culturally sensitive interventions to promote behavioral change. The existence of prenatal and postnatal exposure to mercury, hydroquinone, and other potentially harmful chemicals in skin bleaching products highlights an urgent need to explore the adverse effects of skin bleaching practices on birth outcomes and the growth and neurodevelopment of young babies.

A systematic review of global legal regulations on the permissible level of heavy metals in cosmetics with particular emphasis on skin lightening products

BACKGROUND

There is an urgent need to address the safety problems caused by the use of skin lightening cosmetics. Evidence suggests that some of them may contain heavy metals.

OBJECTIVES

We conducted a systematic review of global legal regulations regarding the permissible level of mercury, lead, arsenic, and cadmium in cosmetic products, with particular emphasis on skin lightening preparations.

METHODS

The systematic search of documents was a two-stage process. First, official websites of 17 regional organizations and subsequently regulations for countries with a population over 100 million were searched.

RESULTS

Fifteen legislative acts, encompassing more than 67·2% of the global population were reviewed. Regulations were identified for 44/59 high income countries, 16/55 upper middle income countries, 9/45 lower income countries, 0/34 low income countries. The median adult literacy rate was 91·4% and 64·2% in countries with and without regulations, respectively. The use of mercury, lead, arsenic, and cadmium has been banned in 67, 67, 65, and 65 out of 69 countries, respectively.

CONCLUSIONS

While regulations exist in most of the high income countries, in low income countries there is a lack of similar standards. In most countries for which these legal regulations have been identified, restrictions on the permissible level of heavy metals are strict. There is a need for enforcement of existing rules, and rigorous assessment of the effectiveness of these regulations.

Multiple low-level exposures: Hg interactions with co-occurring neurotoxic substances in early life

All chemical forms of Hg can affect neurodevelopment; however, low levels of organic Hg (methylmercury-MeHg and ethylmercury-EtHg in Thimerosal-containing vaccines, hereafter 'TCV') exposures during early life (pregnancy and lactation) co-occur with other environmental neurotoxic substances. These neurotoxicants may act in parallel, synergistically, or antagonistically to Hg. Nevertheless, the risks of neurotoxicity associated with multiple neuro-toxicants depend on type, time, combinations of exposure, and environmental and/or genetic-associated factors. Neurological developmental disorders, delays in cognition and behavioral outcomes associated with multiple exposures (which include Hg) may show transient or lasting outcomes depending on constitutional and/or environmental factors that can interact to neutralize, aggravate or attenuate these effects; often these studies are challenging to interpret. During pregnancy and lactation, fish-MeHg exposure is frequently confounded with the opposing effects of neuroactive nutrients (in fish) that lead to positive, negative, or no effects on neurobehavioral tests. In infancy, exposures to acute binary mixtures (TCV- EtHg and Al-adjuvants in infant immunizations) are associated with increased risks of tics and other developmental disorders. Despite the certitude that promulgates single environmental neurotoxicants, empirical comparisons of combined exposures indicate that Hg-related outcome is uneven. Hg in combination with other neurotoxic mixtures may elevate risks of neurotoxicity, but these risks arise in circumstances that are not yet predictable. Therefore, to achieve the goals of the Minamata treaty and to safeguard the health of children, low levels of mercury exposure (in any chemical form) needs to be further reduced whether the source is environmental (air- and food-borne) or iatrogenic (pediatric TCVs).

The global prevalence and correlates of skin bleaching: a meta-analysis and meta-regression analysis

PURPOSE

To estimate and investigate the global lifetime prevalence and correlates of skin bleaching.

METHODS

A meta-analysis and meta-regression analysis was performed based on a systematic and comprehensive literature search conducted in Google Scholar, ISI Web of Science, ProQuest, PsycNET, PubMed, and other relevant websites and reference lists. A total of 68 studies (67,665 participants) providing original data on the lifetime prevalence of skin bleaching were included. Publication bias was corrected using the trim and fill procedure.

RESULTS

The pooled (imputed) lifetime prevalence of skin bleaching was 27.7% (95% CI: 19.6-37.5, I²  = 99.6, P < 0.01). The highest significant prevalences were associated with: males (28.0%), topical corticosteroid use (51.8%), Africa (27.1%), persons aged ≤30 years (55.9%), individuals with only primary school education (31.6%), urban or semiurban residents (74.9%), patients (21.3%), data from 2010-2017 (26.8%), dermatological evaluation and testing-based assessment (24.9%), random sampling methods (29.2%), and moderate quality studies (32.3%). The proportion of females in study samples was significantly related to skin bleaching prevalence.

CONCLUSION

Despite some limitations, our results indicate that the practice of skin bleaching is a serious global public health issue that should be addressed through appropriate public health interventions.

Immunotoxicity of mercury: Pathological and toxicological effects

Mercury (Hg) is toxic and hazardous metal that causes natural disasters in the earth's crust. Exposure to Hg occurs via various routes; like oral (fish), inhalation, dental amalgams, and skin from cosmetics. In this review, we have discussed the sources of Hg and its potential for causing toxicity in humans. In addition, we also review its bio-chemical cycling in the environment; its systemic, immunotoxic, genotoxic/carcinogenic, and teratogenic health effects; and the dietary influences; as well as the important considerations in risk assessment and management of Hg poisoning have been discussed in detail. Many harmful outcomes have been reported, which will provide more awareness.

Current progress on understanding the impact of mercury on human health

Mercury pollution and its impacts on human health is of global concern. The authors of this paper were members of the Plenary Panel on Human Health in the 12th International Conference on Mercury as a Global Pollutant held in Korea in June 2015. The Panel was asked by the conference organizers to address two questions: what is the current understanding of the impacts of mercury exposure on human health and what information is needed to evaluate the effectiveness of the Minamata Convention in lowering exposure and preventing adverse effects. The authors conducted a critical review of the literature published since January 2012 and discussed the current state-of-knowledge in the following areas: environmental exposure and/or risk assessment; kinetics and biomonitoring; effects on children development; effects on adult general populations; effects on artisanal and small-scale gold miners (ASGM); effects on dental workers; risk of ethylmercury in thimerosal-containing vaccines; interactions with nutrients; genetic determinants and; risk communication and management. Knowledge gaps in each area were identified and recommendations for future research were made. The Panel concluded that more knowledge synthesis efforts are needed to translate the research results into management tools for health professionals and policy makers.

Skin Bleaching and Dermatologic Health of African and Afro-Caribbean Populations in the US: New Directions for Methodologically Rigorous, Multidisciplinary, and Culturally Sensitive Research

Skin-bleaching practices, such as using skin creams and soaps to achieve a lighter skin tone, are common throughout the world and are triggered by cosmetic reasons that oftentimes have deep historical, economic, sociocultural, and psychosocial roots. Exposure to chemicals in the bleaching products, notably, mercury (Hg), hydroquinone, and steroids, has been associated with a variety of adverse health effects, such as Hg poisoning and exogenous ochronosis. In New York City (NYC), skin care product use has been identified as an important route of Hg exposure, especially among Caribbean-born blacks and Dominicans. However, surprisingly sparse information is available on the epidemiology of the health impacts of skin-bleaching practices among these populations. We highlight the dearth of large-scale, comprehensive, community-based, clinical, and translational research in this area, especially the limited skin-bleaching-related research among non-White populations in the US. We offer five new research directions, including investigating the known and under-studied health consequences among populations for which the skin bleach practice is newly emerging at an alarming rate using innovative laboratory and statistical methods. We call for conducting methodologically rigorous, multidisciplinary, and culturally sensitive research in order to provide insights into the root and the epidemiological status of the practice and provide evidence of exposure-outcome associations, with an ultimate goal of developing potential intervention strategies to reduce the health burdens of skin-bleaching practice.