In another thread, Tim (@Vecchiouomo) mentioned Arsenic in rice, and that rice grown in California was generally better (less contaminated) than others.
To the best of my recollection, even though this has been known for decades, I hadn’t heard about how rice tends to concentrate arsenic compounds (and plenty of other heavy metals).
I found this chart from Consumer Reports which tested commercially sold rice grown in few different countries and, within the US, in several states. Also, rice products like cereals and cakes were tested.
I’m a little unsettled by the data variability - why would two lots from the same maker presumably grown in the same fields at similar times have such disparate results? Also, they tested blind duplicates of the same sample from time to time, and generally got the same result, but in some cases the two weren’t even close.
But some trends still look useful. Brown rice has a lot more arsenic than white. Rice grown in California and in India seem to be a lot lower in arsenic than rice grown in Louisiana, Missouri or Texas.