Many Mexican Americans regard "Azarcon," a lead tetroxide powder, and "Greta," a lead monoxide powder, as desired medical treatments for empacho, a perceived intestinal blockage. The folk medicines, available in Mexico but not in the United States, can cause lead poisoning, which can result in brain swelling, coma, permanent mental retardation, and death. As of June 1983, the medicines had resulted in 15 confirmed cases of lead poisoning in four states with unconfirmed reports of cases in three more states. Information from a "curandera" (folk healer) and the Colorado family of a 2-year-old victim and results of a survey of Hispanic American migrant families in Colorado indicate that gastrointestinal complaints such as constipation and abdominal pain are regarded as symptoms of empacho. Folk treatments of empacho differ with the severity of the case and range from massage to skin stretching and laxative teas to enemas and purgatives such as "Azarcon" and "Greta." The two substances are given sparingly, either dry or mixed with a liquid, on a 3- or 7-day basis. Because many surveyed Mexican Americans report being treated for empacho, frequently with the lead substances, warnings about "Azarcon" and "Greta" should be the subject of nationwide public health education efforts. (SB)