[Ifeffit] Noise level in XANES spectrum

Hello Everyone, I have a general question regarding noise level of XANES spectrum. I have collected XANES data for an element which is present in ppm level in my samples. Some samples are exhibiting varying degree of noise in XANES spectrum. Is the noise level of XANES spectrum would be proportional or consistent with the concentration of the sample? As XANES spectra for some of my samples with relatively higher concentration of this element are exhibiting greater level of noise than those with relatively lower concentrations. Will sample matrix play any role in the noise level? Thanks and I appreciate your help. regards, Pushan