Quantitative risk assessment of mycotoxins from school milk consumption in Bangkok metropolitan

Mycotoxin transfer from contaminated feed into cow milk and school milkproducts can pose a health risk to children. Dairy cow feed (n= 119), raw milk (n= 36), and school milk (n= 66) samples collected throughout school milk supply chain during the period from August 2018 to March 2019 were investigated for the occurrence and contamination level of mycotoxins using LC – MS/MS. Zearalenone was most frequently detected in dairy cow feed samples, followed by fumonisin B1, deoxynivalenol, and aflatoxin B1, respectively. Zearalenone was detected in all samples of concentrate with a range from 2.47 to 55.60 μg/kg, in 9.6% of roughage samples with a range of 1.25 – 5.26 μg/kg and in 82.3% of mixed feed samples in a range of 0.96 – 12.39 μg/kg. Fumonisin B1 was detected in 63.6% of concentrate samples with a level between 2.66 and 284.26 μg/kg, in 3.8% of roughage samples with a level between 8.03 and 11.94 μg/kg, and in 41.2% of mixed feed samples with a level between 13.22 and 60.80 μg/kg. Deoxynivalenol was detected in 48.5% of concentrate samples in a range from 66.98 to 377.69 μg/kg and in 31% of mixed feed samples in a range from 27.22 to 122.44 μg/kg. Aflatoxin B1 was detected in 39.4% of concentrate samples in a range from 0.73 to 10.67 μg/kg. The contamination levels of zearalenone, fumonisin B1, deoxynivalenol, and aflatoxin B1 detected in dairy cow feed samples were low. Therefore, none of raw milk and school milk samples was found to be contaminated with these mycotoxins. However, aflatoxin M1, deoxynivalenol, fumonisin B1, and zearalenone can be excreted in milk from dairy cows consuming feed contaminated with aflatoxin B1, deoxynivalenol, fumonisin B1, and zearalenone, respectively, leading to the potential health risks to children. A quantitative risk assessment model of aflatoxin M1, deoxynivalenol, fumonisin B1, and zearalenone in school milk was developed for children aged 4 to 12 years old in Bangkok. The results showed that the exposure of these mycotoxins from school milk consumption was found to be highest in 4-to-6-year-old group, followed by 7-to-9-year-old, 10-to-12-year-old, and 4-to-12-year-old group, respectively. The health risk to children from aflatoxin M1 in school milk was assessed using margin of exposure (MOE) approach and cancer potency. The results showed that the health risk to children was low. Sensitivity analysis identified that the prevalence and contamination level in concentrate were strongly associated with health risk to children from aflatoxin M1. For deoxynivalenol, fumonisin B1, and zearalenone, the health risks of children were evaluated by comparing the exposure of each mycotoxin with its tolerable dairy intake. The health risks to children from these mycotoxins in school milk were low. According to sensitivity analysis, carry – over rate and contamination level in concentrate were highly correlated with health risk to children from zearalenone and deoxynivalenol, while prevalence and contamination level in concentrate were strongly associated with health risk to children from fumonisin B1.