A Simple Non-destructive Technique for the Analysis of Mercury in Creams

Abstract

The sale of cosmetic creams is unrestricted in Kenya. Accusations have been levelled on these products due to their having dysfunctious effects on consumers as a result of addition of non conventional skin lightening ingredients like mercury . Mercury occurs widely in the biosphere and has long been known as a toxic element presenting hazards associated with ingestion and inhalation. No vital function for the element in living organisms has yet been found. The toxic properties of mercury have evoked increasing concern lately due to the extent of its use in industries, agriculture and in pharmaceutical preparations like cosmetic creams. Mercury containing creams are left on the skin and therefore the possibility of exposure to mercury exists. This exposure leads to poisoning manifestations which can be neurological and nephrotic. Previous workers in this subject have used an analytical method which involved heating specimens to high temperatures during acid digestion. Considering the volatility of mercury, this method may not have been most reliable hence in this study an essentially non-destructive testing technique has been utilised to determine the levels of mercury in imported cosmetic creams sold in Kenya. Samples analysed for each brand were collected in two groups six months apart. The aim of this kind sampling was to study possible variations in mercury concentration in each brand within the six months period. The analysis showed the following mercury concentration ranges (1l9/9) within brands: Madonna(green) 20867-33508; Madonna(red)14330-22167; Pimplex 3742-9949; Shirley(original)

5444-32270; Bestlady 8837-16187; Topsine 1182-1969; Fennel 3743- 5444; Shirley(new), Dermovate, Topshirley had no mercury within the lower limit of detection of the Energy Dispersive X-ray Fluo~escence (EDXRF) detector. The following variations between the two sample groups were also observed: Madonna(green) 7.3%; Madonna(red) 30%; Pimplex 121%; Shirley(original) 40%; Bestlady 7.4%; Topsine 3.7%; Fennel 14%; Shirley(new),Dermovate, Topshirley 0%. Most of the brands analysed (70%) had mercury levels above the Kenya Bureau of Standards recommendation of 0% and were also above levels reported in previous studies. 30% of the brands showed no mercury concentration within the lower limit of detection of the Energy Dispersive X-ray Fluorescence (EDXRF) detector system used. thus it was observed that most imported cosmetic cream brands contain high levels of mercury and therefore the Kenya Bureau of Standards should find ways of preventing the entry of these products into the country.