J. Cosmet. Sci., 69, 429–445 (November/December 2018) 429 Cosmetic Use in Nigeria May Be Safe: A Human Health Risk Assessment of Metals and Metalloids in Some Common Brands GODWIN CHUKWUEBUKA AJAEZI, CECILIA NWADIUTO AMADI, OSAZUWA CLINTON EKHATOR, SORBARI IGBIRI, and ORISH EBERE ORISAKWE, Department of Medical Laboratory Science, Rivers State University of Science and Technology, Port Harcourt, Rivers State, Nigeria (G.C.A.), Toxicology Unit, Faculty of Pharmacy, University of Port Harcourt, Rivers State, Nigeria (C.N.A., O.C.E., S.I., O.E.O.) Accepted for publication October 21, 2018. Synopsis Twenty different brands of cosmetic products were purchased from supermarkets in Port Harcourt, Rivers State, Nigeria, with the aims to determine the levels of metals and assess the health risk to humans through long-term usage. The concentration of metals (arsenic, lead, mercury, cadmium, and nickel) in the cosmetic samples was measured with atomic absorption spectrophotometry after acid digestion. The concentration of metals in these brands of cosmetic studied ranged from As: 0.001–0.0161 mg/kg, Pb: 0.289–2.873 mg/kg, Hg: 0.001–0.0014 mg/kg, Cd: 0.001–0.334 mg/kg, and Ni: 0.007–2.748 mg/kg. The metal and metalloid contents were less than the regulatory limits set for both metal impurities and as color additives. The target hazard quotient, hazard index, and cancer risk were less than the acceptable limit, indicating a measure of safety. Cosmetics sold in Nigeria may not add to the body burden of metals and metalloids. INTRODUCTION The pursuit for beauty has led to the rapid increase in utilization of cosmetics by millions of people (both men and women) all over the world (1). Cosmetic is a cocktail of chemi- cals that is intentionally applied to the skin surface for the purpose of promoting attrac- tiveness or beautifi cation. Heavy metals such as lead, cadmium, and mercury can be deliberately used as active ingredients in the formulations of cosmetics or may exist as impurities in cosmetics products because of their persistence and ubiquitous nature (2). The natural occurrence of these metals in rock, soil, and water can cause them to be pres- ent in the manufacturing of pigments and other raw materials used in cosmetics indus- tries (3). Although a limited number of ingredients such as lead acetate in hair dyes are Address all correspondence to Orish Ebere Orisakwe at orishebere@gmail.com.
JOURNAL OF COSMETIC SCIENCE 430 permitted under strict conditions of use, the existence of heavy metals in cosmetics as an ingredient has been banned by legislation of most developed countries because they have been found to be harmful and usage of these cosmetics can be injurious to human health (4). The most signifi cant route of exposure to heavy metals in cosmetics is through the dermal route because cosmetics are mostly applied on the skin surface. Oral exposure can occur when it is used around the mouth, as well as hand to mouth contact after exposure to cosmetics containing those heavy metals (5). Oral exposure can also occur in children who tend to rub their eyes during cosmetics irritation and put contaminated fi nger in the mouth (6). Inhalation exposure to cosmetics is usually considered negligible but may be possible through aerosol cosmetics application (7). Metals are of environmental and public health signifi cance because they can initiate a wide range of toxic and chronic health effects such as cancer, reproductive development and neurological disorders, kidney and liver problem, lungs damage, contact dermatitis, brittle hair, and hair loss. Many are also implicated as endocrine disruptors (3). Despite all the regulations and safety systems in place for cosmetics today, the question still re- mains about the safety of cosmetic ingredients and impurities and the standard associated with them. There seems to be no legislation regarding contaminants in cosmetics in Nigeria (1). Many studies have provided scientifi c data on the level of heavy metals in cosmetics but there is a paucity of data regarding the health risk assessment of heavy met- als in cosmetics to which the population may be exposed to. This study was undertaken to determine the concentrations of lead, cadmium, mercury, arsenic, and nickel in cos- metic products and to evaluate the human health risk involved in the daily usage of these cosmetics. MATERIALS AND METHODS SAMPLE COLLECTIONS In January 2014, 20 brands of cosmetic samples (body cream, facial cream, hand cream, lip balm, and hair cream), were purchased from supermarkets and cosmetic shops in Port Harcourt, Rivers State, Nigeria, and used in the study. METAL ANALYSIS Using our previous method (8), the samples were ashed and digested in Tefl on labware that had been cleaned in a high-effi ciency particulate air-fi ltered (class 100), trace metal– clean laboratory to minimize contamination. This protocol involved sequential cleaning of the labware in a series of baths in solutions (1 wk each) and rinses (fi ve per solution) in a three-step order, namely, a detergent solution bath and deionized water rinses, then 6-NHCl (reagent grade) solution bath and ultrapure water rinses, and fi nally, 7.5 N HNO3 (trace metal grade) solution bath and ultrapure water rinses (8). The labware was air-dried in a polypropylene laminar airfl ow-exhausting hood. A dry ashing method was used by adding 30 ml of each sample into a conical fl ask and heating on a hot plate at 200°C for 45 min, and then in a furnace at 500°C until the volume was drastically re- duced to near dryness. Digestion was performed by an addition of 10 ml concentrated
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