This paper presents the results of the proficiency test exercise conducted in Pakistan for the determination of trace elements
in mushroom reference material. Thirteen laboratories from different organizations of the country submitted trace elemental
data on Al, As, Br, Ca, Cd, Ce, Cl, Co, Cr, Cs, Cu, Fe, Hg, K, Li, Mg, Mn, Na, P, Pb, Rb Sc, Si, Sm, Sr, Th, Zn. Results for
Al, As, Br, Ca, Cd, Cl, Co, Cr, Cs, Cu, Fe, K, Mg, Mn, Na, Rb Sc, and Zn, in the mushroom material were reported by two or
more participating laboratories and could be subjected to statistical evaluation. The original data of these trace elements
was subjected to a computer program “Histo Version 2.1” provided by IAEA. The four outlier tests, i.e., Dixon, Grubbs, skewness
and kurtosis were applied to the data sets. Consensus (overall) mean values, absolute standard deviation, relative standard
deviation, standard error, median and range of values for these elements have been reported at a significance level of 0.05.