Seasonal variation in exposure frequency and concentration levels of aflatoxins and ochratoxins in urine samples of boys and girls

Urine samples from children in Sierra Leone (134 boys and 110 girls), were collected during the dry season. During the rainy season samples were colle cted from 97 boys and 93 girls. Analysis of the dry season samples, reveale d that, with the exception of one boy, all children had detectable amounts of aflatoxins and/or ochratoxins in their urine. Similarly, with the except ion of four children (two from each sex), rainy season urine samples also c ontained these two mycotoxins. There were significant differences in the fr equency of exposure to some mycotoxins: ochratoxin A (OTA), p < 0.01; 4-hyd roxyochratoxin A (4R-OTA), p < 0.002; aflatoxin M1 (AFM(1)), p < 0.04; afla toxicol (AFL), p < 0.03; aflatoxin B-2 (AFB(2)), p < 0.04 . There were also significant differences in the levels of aflatoxin B-1 (AFB(1)), (p < 0.05 ) and AFB(2), (p < 0.02) detected in dry season samples. Stratification of these results according to season and sex, has indicated significant differ ences with respect to 4R-OTA (p < 0.04) and AFB(1) (p < 0.02). The results of this study show that in Sierra Leone, children are frequently and consta ntly exposed to both aflatoxins and ochratoxins.