MMA:DMA ratios reversed.

Mark Wheeler's Focus article, "Measuring Mercury" (1), which appeared in the August 1996 issue of EHP, contained a serious omission. Wheeler concentrated on methyl mercury and, to a lesser extent, elemental mercury in dental amalgams. He failed to mention the relatively recently described but extremely significant exposures to elemental mercury in ethnically Hispanic and Caribbean homes, consequent to its use for a variety of magico-religious and ethnomedical purposes (2-3). Such domestic use and presumed exposure has been documented in a number of published papers, as well as by research sponsored by the ATSDR (4-6) and the EPA (7). In fact, an ATSDR monograph specifically alerts clinicians to this exposure pathway: "Metallic mercury has been used by Mexican-Americans and Asian populations in folk remedies for chronic stomach disorders and by Latin-American and Caribbean natives in occult practices" (4). and who has long been aware of elemental mercury's domestic use. Similarly, the EPA's Kathryn Mahaffey, also interviewed, has been aware of domestic mercury exposure for some years, and the EPA issued a risk assessment document on cultural uses of mercury in 1993 (7). These mercury exposures are especially significant from an environmental health perspective because, in many cases, they are certain to be orders of magnitude greater than (methyl) mercury exposures from eating fish or from the leaching of mercury in amalgam fillings. Additionally, the mercury vapor released from mercury intentionally sprinkled on floors affects all occupants of contaminated homes, from the fetus to the elderly. Andrew Rowland, cited in "The Issue of Amalgams" (1), has been aware of domestic mercury exposure for several years. Rowland makes a call for more research on health effects of amalgam-mercury exposure. I make a similar call for research on magico-religious mercury exposure. If the environmental health research community continues to ignore magico-religious mercury exposure, its health effects will never be ascertained. I would like to bring to your attention an apparent typo in a recent response written by Mushak and Crocetti in Environmental Health Perspectives (1). In describing a publication by Warner et al. (2), they note that "the corresponding MMA:DMA ratios for exposed and control subjects were 0.32 and 0.5 ..." (p. 1017, first column). These values should be reversed. As reported by Warner et al. (2) and correctly cited by Mushak and Crocetti in their original commentary (3), urinary arsenic concentrations were 190 mg MMA/l and 390 mg DMA/l for the exposed group, …