I found David Williams' Oct. 25 letter, "Forgoing the new flu vaccination" — regarding mercury in vaccines — to be inaccurate at best and fear-mongering at worst. His concern seems to be that vaccines are routinely preserved with Thimerosal, which he correctly states is roughly 50 percent mercury by weight. What he does not say is that the amount used to preserve the vaccine is used in concentrations of 0.001 percent to 0.01 percent (according to the U.S. Food and Drug Administration Web site on mercury in vaccines).
The FDA also says that, at the higher concentration of 0.01 percent, a 0.5-milliliter dosage of vaccine would have about 25 micrograms of mercury. Various organizations, including the Environmental Protection Agency and the World Health Organization, state that the safe dosage for methyl mercury (Thimerosal is ethyl mercury) is somewhere between 0.1 and 0.47 mg per kilogram per day, or between 6 and 28 mg per day for a 60-kg person. By comparison, a 170-gram serving of canned tuna can have as much as 50 mg. The FDA Web site mentions a study done at the Bethesda Naval Medical Center of infants who received vaccines, indicating that ethyl mercury cleared much faster from infants' blood than methyl mercury, and the mercury levels in the infants' blood never exceeded safety guidelines.
No one is debating whether the ingestion of mercury is good for you, and efforts to eliminate mercury from vaccines should of course continue. However, Williams' implications do everyone a disservice. What he chooses to do or not to do regarding vaccination is his business; however, he should not misrepresent facts in a letter. It took me less time to look up the information on Thimerosal from a reputable source than to actually write this letter.