Detection of Mercury in Skin Lightening Cosmetics Marketed in Katsina Metropolis, Katsina State, Nigeria

Abstract

Deliberate use of metals as active cosmetic ingredients has been banned in many countries due to their persistent nature, toxicity and  transdermal exposure over a certain period of time. Fifteen (15) samples were purposively sampled to cover the most frequently used  brands as the samples for the study. The samples cover five (5) of each of the skin lightening creams, lotions and soaps from different  cosmetics shops in Katsina central market and other outlets within the metropolis of Katsina. Qualitative inorganic analysis was  conducted for the detection of the presence of mercury in the samples. Also quantitative analysis of the mercury was carried out using  Atomic Absorption Spectrometry (AAS). The results for the qualitative inorganic analysis showed that all the samples were mercury (II)  positive with 0.5N KI reagent through the formation of reddish orange precipitate, and no positive reaction of mercury was detected  using 2.0N NaOH reagent. Quantitative analysis of the mercury revealed the presence of mercury in all the analyzed samples. The  concentration of mercury ranged from 27.7 ± 0.0006 to 61.5 ±0. 0007 ppm. From the results obtained, it is thus evident that the analyzed  samples were mercury (II) positive and above the recommended WHO permissible limit. Therefore, there may be a serious health hazard  to the users of such products in Katsina metropolis. It is recommended that periodic analysis of such skin lightening products should be  conducted by the regulatory bodies to ascertain their safety to the users.