Application of Handheld X-Ray Fluorescence Analyzers to Identify Mercury in Skin-Whitening Creams in Cambodia

Abstract

Background. A well-documented source of mercury contamination is skin-whitening cream. The heavy metal is sometimes added to the cream to block production of melanin. Past studies have shown that about one third of skin whitening creams for sale in Phnom Penh contained mercury levels considerably higher than both United States and Association of Southeast Asian Nations (ASEAN) guidelines. Developing nations such as Cambodia do not have the resources for monitoring and enforcement. Objectives. Evaluate the utility of handheld X-ray fluorescence analyzers for detection of mercury in skin-whiteners. Methods. A handheld XRF unit was used to measure the total mercury content of 676 skin-whitening creams collected from volunteers from a cross-section of Phnom Penh's residents. Results. About 16% of bleaching creams collected contained more than 20 ug/g of mercury. The highest concentration was about 35,000 ug/g. A third of the samples that were custom-made or modified by beauty shops contained more than 20 ug/g of mercury. Conclusions. The handheld XRF analyzer proved an excellent tool for screening mercury in skin creams, and could be particularly useful in developing countries because it is relatively inexpensive, requires no sample preparation or extraction, can be used by staff with little technical background, and can facilitate on-site education.