OCCURRENCE OF AFLATOXIN M1 IN RAW MILK DURING THE SUMMER AND WINTER SEASONS IN HAMEDAN, IRAN SEYED AMIR GHIASIAN 1,4 , AMIR HOSSEIN MAGHSOOD 1 , TIRANG R. NEYESTANI 2 and SEYED HOSSEIN MIRHENDI 3 1 Medical Parasitology and Mycology Department School of Medicine Hamedan University of Medical Sciences and Health Services PO Box 65155-518, Hamedan, Iran 2 Laboratory of Nutrition Research National Institute of Nutrition and Food Technology Researches Shaheed Beheshti University of Medical Sciences Tehran, Iran 3 Medical Parasitology and Mycology Department School of Public Health Tehran University of Medical Sciences and Health Services Tehran, Iran Accepted for Publication July 24, 2006 ABSTRACT A survey on the occurrence of aflatoxin M 1 (AFM 1 ) was carried out in summer and winter in raw milk samples from 93 traditional and industrial dairy farms of the Hamedan district in order to address representative data on AFM 1 in milk collected from these regions. Of the 186 milk samples, AFM 1 was detected in 119 samples (63.97%). The mean concentration of AFM 1 in con- taminated samples was 43.4 ng/L, and the minimum and maximum levels were 10 and 410 ng/L, respectively. Fourteen (11.76%) contaminated samples had AFM 1 in concentrations in excess of the maximum levels specified in European Union regulations, i.e., 50 ng/L. The contamination ratio of milk in summer and winter months was 56.5 and 71.7%, respectively (P < 0.02). This is the first report on AFM 1 determinations in raw milk from western Iran, one of the main milk-production areas, as well as comparison between milk obtained from different dairy farms in Iran. 4 Corresponding author: TEL: +98-811-827-6298; FAX: +98-811-827–6299; EMAIL: s.a.ghiasian@ umsha.ac.ir Journal of Food Safety 27 (2007) 188–198. All Rights Reserved. © 2007, The Author(s) Journal compilation © 2007, Blackwell Publishing 188