LEVELS OF HEAVY METALS (Pb, Hg, Mn, Cu and Cr) AND HUMAN HEALTH IMPLICATIONS OF SOME SELECTED COSMETICS COMMONLY SOLD IN NIGERIA

Abstract

Cosmetics application cuts across all gender and tribe and is considered as essential components in life. This study investigates the levels of heavy metals (Pb, Hg, Mn, Cu and Cr) and human health implications of some selected cosmetics commonly sold in Nigeria. Twentyone (21) randomly selected cosmetics samples was analyzed in triplicate using Atomic Absorption Spectrophotometer (AAS) Varian Spectra AA 55B Model and cold vapor unit for Hg. The results of the analysis revealed varying levels of the metal contaminants in the selected cosmetics and in the order: lotions > creams > soaps. The mean metal levels observed were below the suggested permissible limits for skin protection as set by WHO and US FDA standards. Statistical analysis of experimental data showed that metal levels in the studied cosmetics were significantly different (p < 0.05). Risk to human health on exposure was evaluated at 50% and 100% bio-accessibility of the selected metals and also revealed that Margin of Safety (MoS) levels ranged from 3.29E–01 to 1.23E+07 and 1.64E–01 to 6.17E+06 in lotions; 3.02E–01 to 8.15E+06 and 1.51E–01 to 4.08E+06 in creams; 1.28E+04 to 1.52E+11 and 6.41E+03 to 7.59E+10 in soaps at 50% and 100% bio-accessibility respectively. The highest and lowest systemic exposure dosage (SED) values (mgKg-1BWday- 1 ) were recorded for Pb (1.33E+00 and 1.68E–05), while hazard quotient (HQ), hazard index (HI) and lifetime cancer risk (LCR) levels were higher than permissible limits except for Hg. Thus, continuous usage over time poses threats to human health. Key words: heavy metals, cosmetics, Nigeria, human health and hazard index.