For those that say thimerisol is better than elemental mercury
Brain concentrations of total mercury were approximately 3–4 times lower in the thimerosal group than in the methylmercury group, and total mercury cleared more rapidly in the thimerosal group (with a half-life of 24.2 days versus 59.5 days). However, the proportion of inorganic mercury in the brain was much higher in the thimerosal group (21–86% of total mercury) compared to the methylmercury group (6–10%). Brain concentrations of inorganic mercury were approximately twice as high in the thimerosal group compared to the methylmercury group. Inorganic mercury remains in the brain much longer than organic mercury, with an estimated half-life of more than a year. It’s not currently known whether inorganic mercury presents any risk to the developing brain.