ABSTRACT
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.
Subject(s)
Global Health , Mercury Poisoning/etiology , Mercury/analysis , Skin Lightening Preparations/analysis , Skin Pigmentation/drug effects , Administration, Cutaneous , China , Evaluation Studies as Topic , Humans , Japan , Mercury/adverse effects , Mercury Poisoning/epidemiology , Ointments/adverse effects , Ointments/analysis , Risk Assessment , Skin Absorption/physiology , Skin Lightening Preparations/adverse effects , Spectrometry, Fluorescence/methods , Sri Lanka , Taiwan , Thailand , United States , United States Food and Drug AdministrationABSTRACT
BACKGROUND: Nickel and cobalt are common causes of metal allergy. OBJECTIVE: The objective of this study was to investigate nickel and cobalt exposure in belt buckles by testing 701 belts purchased in China and the United States and to consider the prevalence of nickel allergy and its relevance among Chinese patients. METHODS: Seven hundred one belt buckles purchased in China and the United States were tested for nickel and cobalt release. Six hundred thirty-one Chinese patients with suspected allergic contact dermatitis were patch tested and interviewed to determine clinical relevance of results. The Chinese and American literature was reviewed to investigate trends in nickel prevalence over the past decades. RESULTS: Sixty percent (n = 219) of belts purchased in China (n = 365) released nickel, and 0.5% (n = 2) released cobalt; 55.7% (n = 187) in the United States (n = 336) released nickel, and 0.9% (n = 3) released cobalt. Belt dermatitis was a significant clinical finding in 34.8% of Chinese nickel-allergic patients. Literature review suggests increasing nickel allergy prevalence in the United States and China. CONCLUSIONS: Metallic belt buckles are an important source of nickel exposure to consumers. Belts from lowest socioeconomic vendors were more likely to release nickel. Belts with silver color and dark metallic color were more likely to release nickel and cobalt, respectively. Clinical findings show belt dermatitis in China to be a problem.
