Dear Illusive Fantasy -
I suppose part of it is to acknowledge that organic just means natural. Arsenic is natural. Mercury is natural. All these things are found in nature. There's lots of natural things that, when eaten, will kill you. So organic is just about not adding any *more* trouble to the world
. It's not necessarily about removing what is already there.
White rice is actually better for you, in terms of arsenic. It's the brown rice which is worse.
I wouldn't call it contaminated. It's the way nature meant for it to be.