I eat raw rice on a regular basis about 1/3 to 1/2 cup a day. I can't seem to stop. Is this serious or are there any health risks?

Pica. Eating raw rice can cause gastrointestinal problems. But the more important question is "why do you want to eat raw rice?" you may have pica, a condition that can be associated with iron deficiency anemia. You should see your primary care doctor for further evaluation.
PICA? I agree with dr. Avashia. Need to go to see your doctor and tell your doctor about your habit. This could be a pica- and could be associated with iron deficiency anemia etc. Need to get blood work to see what is going on. Start with your primary care doctor.