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.
Details are in the study, linked in the title of this post. Here’s a diagram from the abstract:
The article explains the infographic and adds a lot more context.
The amount of arsenic depends on location - if you’re in a region that has standards on arsenic levels, like the EU, UK, or the US, then you’re probably fine, but the levels may be higher than what’s considered safe for children. This method would allow you to reduce the levels by around 50%, and since the levels for children are a bit under half of what’s acceptable for adults, that’s likely to make it safe for them.
The time savings are relative to other methods for reducing arsenic content, like cooking it with excess water (like a 12:1 ratio) and then discarding the excess, as this method allows you to use a rice cooker for the remaining time and to cook with a much smaller water:rice ratio, even accounting for the discarded water.