Sources of rare earth elements (REEs) and range of doses used for all REE soil exposure experiments.

a In all cases, seven doses (+ controls) were used, with successive doses following a geometric progression of 1.9.
b %REE refers to the ratio of the molar mass of the rare earth element to the molar mass of the REE source compound, and is given as a percentage.
c The true hydrate form was not clearly known although it was most likely a hexahydrate.
Sources of rare earth elements (REEs) and range of doses used for all REE soil exposure experiments.