Inverse relationship between zinc/iron ratio and toxic metal concentration. The inverse relationship between the logarithmic zinc/iron ratio and (a) aluminum, (b) lead, and (c) molybdenum concentrations in autistic children (N = 2550) is shown. Each point represents the corresponding logarithmic zinc/iron ratio and (a) aluminum, (b) lead, and (c) molybdenum concentration of the individual child. A highly significant inverse relationship between the zinc/iron ratio and aluminum, lead, cadmium, and molybdenum concentrations (r = −0.551, −0.486, and −0.548, respectively, P < 0.00001) in the autistic children is shown.