The direct answer to your question is wanting from the literature I think (though I only looked for a short time. However, I did find several references that would lead me to believe that this particular bioactive from cannabis would not likely accumulate to any really significant degree, at least in blood or oral fluid.

1. Cleared rapidly from oral fluid of chronic users - CBD not detectable other than at baseline in chronic users that are confined and undergo supervised non-use period: Clin Chem. 2011 Aug;57(8):1127-36. doi: 10.1373/clinchem.2011.164822. Epub 2011 Jun 15. Oral fluid cannabinoids in chronic, daily Cannabis smokers during sustained, monitored abstinence. Lee D1, Milman G, Barnes AJ, Goodwin RS, Hirvonen J, Huestis MA. 

2.After single use: CBD is not detectable in Serum or urine 1 hour after use: Schwope et al 2011 Identification of Recent Cannabis Use: Whole-Blood and Plasma Free and Glucuronidated Cannabinoid Pharmacokinetics following Controlled Smoked Cannabis Administration. Clin. Chem. 2011 October ; 57(10): 1406–1414. doi:10.1373/clinchem.2011.171777.

3. There are a number of review articles published in a variety of ways purporting to address pharmacokinetics but I did not get them and nothing was available free on the web that hinted at the information? Couple of examples:  

A. Cannabinoids - Handbook of Experimental Pharmacology Volume 168,  2005,   pp 657-690: Pharmacokinetics and Metabolism of the Plant Cannabinoids, Δ 9-Tetrahydrocannibinol, Cannabidiol and Cannabinol. by M. A. Huestis

B. Clinical Pharmacokinetics. April 2003, Volume 42, Issue 4, pp 327-360.  Date: 30 Sep 2012. “Pharmacokinetics and Pharmacodynamics of Cannabinoids” by Dr Franjo Grotenhermen

Hope this was helpful - good luck.