Why you should know:
Arsenic is a carcinogen and has various other negative health effects; enough to warrant exposure limits in various jurisdictions. A five minute boil-and-discard step before cooking is a simple way to reduce your exposure, especially if you eat a lot of rice.
Aren’t you better off with plum or peach seeds?
Best not to eat any, but it’s still a matter of dose. Plum/peach seeds may be more a choking hazard than any other.