Farm-to-fork risk assessment of aflatoxin M1 in milk under climate change scenarios-A comparative study of France and Ireland

Changes in temperature and precipitation patterns due to climate change (CC) may affect the growth of fungi and the subsequent release of toxic metabolites (mycotoxins). Aflatoxin B1, a human carcinogenic mycotoxin produced by Aspergillus flavus (A. flavus), can be found in animal feed and further metabolised into aflatoxin M1 (less carcinogenic) in bovine milk. This research developed a probabilistic model in the farm-to-fork continuum to assess the potential risk from aflatoxin M1 in milk (Irish and French consumers) under current and future CC scenarios. The effects of temperature and relative humidity changes on aflatoxin B1 were examined. The stepwise exposure assessment model considered A. flavus growth during pre-harvest, aflatoxin B1 production, carry-over rate from feed to milk (in aflatoxin M1 form), and human consumption. Results suggest that the cancer risk from aflatoxin M1 is relatively low under climate change scenarios as the estimated margin of exposure was greater than 10,000 (5th percentiles: 48,060 and 79,394 for males and females, respectively). Aflatoxin M1 level in milk (95th percentiles) did not exceed the European Union's maximum permissible limits (50 ng l-1) under all scenarios. Temperatures during the plant growth period (correlation coefficient +0.78), whole milk consumption (+0.29), tillage practice (+0.25), beta coefficient (+0.18), and initial inoculation (-0.17) were found to be the most sensitive parameters to the model output. These findings help to inform farmers and policymakers to adopt mitigation strategies against CC and be climate ready. Future work may include further model development for exposure assessment of multiple mycotoxins in milk, potentially from animal feed materials produced in various geographical regions.