Apparently the husk around the brown rice grain is not so good for you. White rice is actually slightly better I'm lead to believe.
I'm sure a bit of brown rice won't kill anyone though. Unless you reheat it wrong of course ha ha .
That's from heavy metal ppm concerns. Shouldn't be an issue if you rinse it before cooking. I actually soak my grains over night, and rinse again before cooking. Otherwise it takes forever to cook.