Uptake of trace amounts of aluminum into the brain from drinking water.

Throughout the world, alum (aluminum sulfate) is used in municipal water treatment plants to clarify water. Alum treatment usually removes aluminosilicate particles from drinking water but can substantially increase its soluble aluminum content (Zhang et al., 1994; Tran et al., 1993; Kopp, 1970). Soluble aluminum is the more bioavailable and potentially toxic form. We gavaged simulated tap water, containing a low level of radioactive soluble aluminum (26Al), into the stomachs of rats. Measurements with accelerator mass spectrometry showed that trace amounts of 26Al from this single exposure directly entered their brain tissue. Uptake of a comparable level of aluminum into the human brain, from alum-treated drinking water over a prolonged period of time, may contribute to long-term health consequences for some people.