Cadmium, lead and mercury levels in feeding yeast produced in Czechoslovakia

Ninety-six samples of the feeding yeast known as VITEX were analyzed for Cd, Pb and Hg content during 1987-1989. Cadmium content ranged from 0.30 to 5.12 mg/kg(-1), lead content from 0.21 to 3.01 mg/kg(-1) and mercury content from 0.008 to 0.187 mg/kg(-1). Our findings meet the current government standards (max. allowed Pb = 5.00, Cd = 0.50 and Hg = 0.100 mg/kg(-1)) only for lead, and with five exceptions, for mercury. With two exceptions, all cadmium levels found in the samples exceeded the limit. One raw material - the wood chips - was shown to be the main source of cadmium in the technological process. Relatively high Hg contents were measured in the wood chips (up to 0.155 mg/kg(-1)); the highest Hg level (1.105 mg/kg(-1)) however was found in a sample of KOH.