However, the center says, the Dow study attributes the difference to smoking, but the NCI study does not, and it does not rule out implants as a possible cause. The NCI study also found higher rates of suicide for the silicone-implant users. Another study, the center says, found high levels of platinum in the breast milk of women with silicone implants. These findings could make FDA's pending decisions on silicone implants even more difficult.