Comment on “Screening the Multi-element Content of Pleurotus Mushroom Species Using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES)”

La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu are lanthanides, also referred to as “rare earth” elements (occurring at ultra-low concentration, i.e. each, at ppb or lower levels) in plant and animal foods including edible wild mushrooms. Could it be that lanthanides when collectively reported as a summed value (widely referred to as REE) are at relatively high concentrations because extremely high contributions from individual elements? REE elements naturally occur in environmental media such as the soil substrate in which plants and fungi grow in a characteristic pattern (Oddo-Harkins rule), with most of the available literature confirming the extension of this pattern in fungi. Abnormalities therefore need to be examined closely and resolved.