Wide use of skin-lightening soap may cause mercury poisoning in Kenya

In a previous study, we speculated that some of the high mercury levels obs erved in head hair from a total of 14 subjects who resided around Lake Vict oria, Tanzania, might be attributable to the habitual use of toilet soap co ntaining considerable amounts of mercury (Harada et al. Sci Total Environ 1 999,227:249-256). In August 1998, the current study was conducted to invest igate if such mercury-containing soap was also available in the surrounding s of Lake Victoria, Kenya, and if so, its toxic effects. A total of nine go ldminers, 44 fishermen and their families, and 12 residents of Kisumu City, Kenya, volunteered for the study. Fourteen types of toilet soap were colle cted in Kisumu. Total mercury content was very significantly higher than in European-made soap (0.47-1.7% as mercury iodide) compared with Kenya-made soap (0.41 X 10(-4)-6.2 X 10(-4)%). Indeed, all the subjects with a high ha ir mercury level (> 36.1 ppm) had made habitual use of European-made soap, accompanied by various symptoms, such as tremor, lassitude, vertigo, neuros thenia, and black and white blots, suggesting inorganic-mercury poisoning. On the other hand, any subject who had used soap other than the European-ma de soap, did not exceed a mercury level of 10 ppm in hair that is well with in normal limits (Harada et al. Sci Total Environ 1999;227:249-256). The fi ndings obtained suggest that the mercury-containing soap must be barred fro m circulation without delay, and that the residents' health in addition to the environmental pollution in Lake Victoria (Kenya as well as Tanzania) sh ould be kept under close observation. (C) 2001 Elsevier Science B.V. All ri ghts reserved.