determination of aflatoxin m1 in pasteurized and uht milk in west-azerbaijan province of iran

background: aflatoxin m1 (afm1) as a carcinogenic and toxic compound has considerable significance from public health viewpoint. the aim of this study was to determine the level of afm1 in pasteurized and uht milk in west-azerbaijan province of iran. methods: a total of 360 commercial milk samples including 220 pasteurized milk and 140 ultra-high-temperature (uht) milk were purchased randomly from large supermarkets and retail shops in seven different cities of west-azerbaijan province of iran. concentration of afm1 in the samples was investigated by enzyme-linked immunosorbent assay (elisa) method. statistical analyses were carried out using spss version 16.0. results: from total of 360 samples, 77.7% (n = 280) were contaminated to afm1 with a mean of 75.8 ± 9.2 ng/l.  seventy percent (n=154) of pasteurized milk and 54.2% (n=76) of uht milk, exceeded the limits recommended by european commission (ec) regulations (50 ng/l). besides, 2.27% of pasteurized milk (n=5) and 2.1% of uht milk (n=3) exceeded the prescribed limit of institute of standards and industrial research of iran (isiri) and us food and drug administration (fda) regulations (500 ng/l). mean content of afm1 in contaminated pasteurized and uht milk samples were 76.2 ± 8.4 and 72.6 ± 7.2 ng/l, respectively with no significant difference (p>0.05). conclusion: we found high presence of afm1 in milk samples which may pose a serious health hazard to local people. therefore, milk and dairy products should be monitored continuously for this issue. also, it is necessary to educate dairy farmers about effective ways to reduce aflatoxin contamination.