Arsenic is a semi-metal that is odorless and tasteless. It gets concentrated in our food and drinking water supplies from natural deposits in the earth or from agricultural and industrial practices involving pesticides and more.
Arsenic has been linked to cancer of the bladder, lungs, skin, kidney, nasal passages, liver, and prostate. Non-cancer effects can include thickening and discoloration of the skin, stomach pain, nausea, vomiting; diarrhea; numbness in hands and feet; partial paralysis; blurred vision and blindness.
The level of arsenic in our rice is high enough to cause these problems to manifest themselves.
Yes, there is reason for concern.