Heavy Metals Contents of Commonly‐used Cosmetics at Ahmadu Bello University, Zaria, Nigeria

다국어 초록 (Multilingual Abstract)

Cosmetics are preparations used in contact with various parts of the body such as epidermis, hair, nails, teeth, lips, genitalia; and mucous membrane of the oral cavity, for purpose of cleaning, perfuming, protecting, changing appearances for ‘better’, converting body odours to pleasant fragrances, and generally keeping body surfaces in good condition. Several studies have shown unacceptable levels of heavy metals in cosmetics, and which were linked to chronic toxicities. The aim of this study was to determine heavy metals contents of commonly‐used cosmetics at Ahmadu Bello University Zaria ‐ one of Nigeria’s 165 universities, which offers 520 programs by 98 academic departments housed in 16 faculties with total student and staff populations (and approximate female percent representation) of >60,000 (~35%) and >10,000 (~20%) respectively. A survey at its main campus, revealed 11 cosmetic shops while some of the other 415 on‐campus shops also sold diverse cosmetics. These included body creams/lotions/toners (150 different brands), perfumes/splashes (145), soaps (93), face powders (57), lipsticks/lip glosses (33), shampoos (30), toothpastes (9) and shaving creams/powders (7). Using purposive/convenient sampling techniques, students from all 6 departments in the Faculty of Pharmaceutical Sciences, were served a link to a questionnaire deployed on Survey MonkeyTM platform; and the first 100 respondents‐indicated most‐commonly‐used cosmetics were identified, and analysed for 11 elements using flame atomic absorption spectrophotometer. Thus, 10 cosmetics used by the (stated percentage of participating) students, namely: oral‐B toothpaste (46%), veets shaving cream (32%), petals shampoo (19%), dettol medicated soap (19%), eva soap (19%), absolute lip gloss (16%), huda beauty pure matte lipstick (15%), iman makeup pressed powder (12%), dove lotion (7%) and jergen’s shea butter lotion (7%) were analysed; but not abraaj oud perfume (8%) due to the latter’s volatility. The concentrations in ppm were determined for the heavy metals; and compared where applicable, with standard limits set by the FDA, Health Canada, EU and WHO. The values obtained were: calcium (0.031–1.542), cadmium (0.001–0.067), cobalt (0.013–0.408), copper (0.004–0.178), iron (0.131–10.779), lead (0.00–0.590), magnesium (0.001–0.388), manganese (0.001–0.928), nickel (0.00–2.720), sodium (0.000–0.022) and zinc (0.000–0.736). None of the 11 heavy metals was undetected in all the 10 cosmetic samples studied; and the lipstick had the highest levels of 5 heavy metals ‐ cobalt, copper, magnesium, manganese and nickel. In addition, the concentration of nickel in the lipstick analysed, being 2.720 ppm, was several times higher than some nickel standard limits e.g. those specified by FDA (<0.6 ppm) and EU (<0.6 ppm), but not the standard limits specified by Health Canada (<10 ppm) and WHO (<10 ppm). While the vast majority of heavy metals contents of the cosmetics studied were below specified concentrations, possibilities of their accumulation in biological systems over time, constitute potential health risks. Absence of obvious standard limits for many heavy metals plus large disparities in those specified by various regulatory bodies complicate assessment of cosmetics toxicity.