Possible sources of ochratoxin A in human blood in Poland.

Samples of plant origin and human and porcine blood samples were screened over a long period for the presence of ochratoxin A. Of 1353 cereal samples, 11.7% contained the mycotoxin; of 1372 samples of feed, 1.5%; of 368 bread samples, 17.2%; of 215 flour samples, 22.3%; of 894 porcine serum samples, 37.4%; and of 1065 human serum samples, 7.2%. Seasonal variations in the natural occurrence of ochratoxin A were observed, with an increased percentage of positive samples in the spring. Individual daily intake of the mycotoxin, estimated on the basis of residues in human serum, was found to be 0.4 ng/g of food consumed.