Levels of ochratoxin A and IgG against conidia of Penicillium verrucosum in blood samples from healthy farm workers.

Ochratoxin A (OTA) is a mycotoxin frequently found in human blood and milk samples in the colder climatic zones. In addition to dietary intake, exposure may occur by inhalation of toxin containing fungal conidia. The purpose of this work was to investigate the level of OTA in blood samples from farm workers and non-farm working controls, and to examine if serum levels of OTA were related to inhalatory exposure to conidia of Penicillium verrucosum, the main OTA producer in temperate climates. Blood samples from 210 participants were analysed for the presence of OTA and IgG antibodies against P. verrucosum conidia. The concentration of OTA was determined by HPLC (DL 10 ng/l), and the IgG level was determined by ELISA. All serum samples contained OTA (mean 397 ng/l, range 21-5534 ng/l). The OTA level in serum was unrelated to farm working, gender, age, and IgG level. The mean IgG level was significantly higher among farm workers than controls. Farm working, or increased inhalatory exposure to P. verrucosum, was not related to higher OTA serum levels. Inhalatory exposure to OTA from farm working seems to be of minor importance compared to dietary intake.