Climate change and aflatoxins, the support of predictive models in emerging risk management.

The impact of climate change on food and feed safety has been identified as an emerging issue - due also to possible changing patterns of mycotoxin contamination in cereals such as wheat, maize and rice. In particular, aflatoxins (AFs) - which frequently occur in tropical and sub-tropical areas - are increasing the concern that they cause in Europe. Aspergillus flavus and A. parasiticus, the main AF producers, are xerophilic fungi. With climate change and the expected increasing temperature and decreasing rain, these fungi may find conditions that are more suitable for their development. Therefore, the aim of the current study was to estimate the impact of climate change on AF contamination in cereal crops to assess the potential effect and to draw maps of the predicted AF contamination on a regional basis. The AFLA-maize model, linked to crop phenology data, was used as predictive tool. The model was originally developed for maize crop and feed with hourly data; it was adapted to use daily data as input, because only this time scale is available for climate change scenarios data. Furthermore, the model was linked to wheat and rice phenology to enlarge its application to these cereal types. For this purpose, the outputs of the HadCM3 General Circulation Model (GCM) were downscaled for current climate (1975 –2005) and two future scenarios (present, +2°C and +5°C above pre-industrial levels) as simulated by the HadCM3 A2 scenario. This procedure was based on the use of the LARS WG weather generator that allowed including changes in mean climate as well as in climate variability as derived from a GCM in future climate simulations and produce 100 years of synthetic daily weather data for each scenarios (present, +2°C, +5°C) for each 50 × 50 km grid point. The risk of AF contamination was predicted in each of the three climate change scenarios using AFLA-maize model, predicted crop flowering and harvest dates, and meteorological data. Results on climate, crop phenology and AF risks were used for statistical analysis and mapping. Predictions showed a reduction in season length and an advance in flowering and harvest dates for all the crops considered; this could allow an enlargement of the crop growing areas towards the north of EU, mainly for maize and rice, because earlier ripening would then be possible in these areas. In the +2°C scenario, increased AF contamination is expected in the areas where maize is currently grown whereas in the +5°C scenario, contamination in maize was predicted to be lower, but risk areas are expected to be wider and enlarged towards northern EU countries. The predictions confirmed that maize is the cereal crop of concern and that both human and animal could be exposed to a high AF risk, especially in some EU regions. Wheat was predicted to for a negligible AF risk and rice was not expected to undergo any risk . The risk maps produced could be used as a communication tool to reinforce prevention of AF risks by identifying priority locations for intervention. Work supported by European Food Safety Authority (EFSA) EFSA-Q-2009-00812