Mostly, researchers are using whatman filter papers for analytical purposes. you can refer the attached file to find out the trace elements in whatman.

http://www.chimica.unipd.it/nicola.tiso/pubblica/_private/Utile/catalogo%20whatman.pdf

Unfortunately even the "cleanest" filter papers (or any other consumable lab item) will have some elemental contamination, despite the manufacturer's claims (note that on p20 of the brochure linked above doesn't specifically mention Cd, and on p5 the table lists "typical values"). You will have to do some method blanks to see how much Cd you are getting. My previous lab often found Cd from the yellow colouring of pipette tips (200uL)  and centrifuge tube caps got into acid digestions of plant tissue.

It depends somewhat on the sensitivity of your method. If the paper adds 0.1 concentration units to a reading, and your soils are 1-10 units, then it might be a problem. If the soils are 100-1000 units, then the paper won't change much in the scheme of things. If the paper contamination is variable, and the soil values are low/ near to the paper blank concentrations then you have a significant problem.

The best course of action is to test each batch of filter papers (plus all the other items in your method) to see if their is a detectable amount of Cd (or whatever is your element of interest). If it is below detection limits of your analytical instrument, then you're fine. If you do see something, you have to choose between (1) looking for another brand with less contamination and (2) monitoring the background Cd level in blank samples and hoping the minimum level in your soil is much higher than the background in the paper. (Option 1 takes time, option 2 more quality control samples). Even with a new brand (or grade of paper) you will still have to test each new batch or lot, as the manufacturers may change their suppliers too.

Thanks for helpful answers. Is there any digestion methods for filter papers digestion?

Thanks

Is there any problem of cadmium pollution in soil samples filtration by filter papers

I don't think any problem if you can use watman NO. 41 filter paper (Sources: EPA Method 3050B).

I think you can design an experiment using ddH2O as control.

I have worked with Cd for many years and have experienced contamination and loss in the most unexpected ways.  I do not filter unless absolutely necessary and then only through HCl washed paper or preferably PTFE membranes.

Amplifying on some of the previous comments,  1 M HCl efficiently strips Cd not only from filter paper but also from glass, polythene, PTFE and polypropylene.  I prefer to extract soils and centrifuge in the same tube. I use it to clean micropipettor tips before use.  Avoid any red/orange/yellow colored plastics as the pigments may be Cd compounds.

As others have noted, the degree of problem with contamination and loss depends on the Cd concentration in the samples.  In my case the solution concentrations are typically in the micrograms/L range with quantitation using ICP-MS.  At such concentrations dust can be problematic and its effetcs are evident as 'shot' contamination.