Comment on “Traditional Tibetan Medicine Induced High Methylmercury Exposure Level and Environmental Mercury Burden in Tibet, China”

Abstract

M ercury (Hg) is ubiquitous in the environment with global emissions estimated at nearly 7527 Mg annually, some 70% from primary natural reservoirs and reemission processes. The remainder, anthropogenic sources, are principally fossil-fuel fired power plants, gold mining, nonferrous metals manufacturing, cement production, waste disposal and caustic soda production. 1 Despite its toxicity, Hg has a long history of use in Asian medicines including Ayurveda, 2,3 Traditional Chinese Medicine (TCM), 4,5 and Traditional Tibetan Medicine (TTM). 6 Last year Liu et al (the authors) published a research article in Environmental Science & Technology entitled "Traditional Tibetan Medicine Induced High Methylmercury Exposure Level and Environmental Mercury Burden in Tibet", that theoretically models the fate of Hg consumed as TTM, to high levels of Hg in Tibet's municipal sewage measured previously. 7 In our view, the paper has a number of short comings limiting the significance of the work and making it unlikely that the findings are directly informative for assessment of individual or population risks associated with TTM and the wider burden of mercury in the environment.