Determination of exposure to aflatoxins among Danish workers in animal-feed production through the analysis of aflatoxin B1 adducts to serum albumin.

Aflatoxin B1 is suspected as an etiologic factor in the increased risk for primary liver cancer among workers in animal-feed processing plants in Denmark. Aflatoxin bound to serum albumin was therefore measured for feed-processing workers. Blood samples were collected immediately after vacation and after four weeks of work, and aflatoxin was quantified by competitive enzyme-linked immunosorbant assay. Seven of 45 individuals with an estimated exposure of 64 ng aflatoxin B1.d-1.kg-1 body weight were positive. Three positive workers had been unloading a cargo with an aflatoxin B1 level of 26 micrograms.kg-1 raw material. The exposure level correlated well with the job titles. Dust samples collected at different sites showed considerable variation in the amount of aflatoxin B1 (nondetectable to 8 micrograms.kg-1 dust). The exposure to aflatoxin B1 may only partially explain the increased risk of liver cancer.