Thesis title: Exposure to Alternaria toxins in Italian population
Mycotoxins are toxic compounds produced through the secondary metabolism of certain toxigenic fungi, mainly belonging to the genera Aspergillus, Penicillium and Fusarium, and can contaminate food through the various stages of production and processing, during cultivation, harvesting, transport, storage, and manufacturing. Molecular structures of mycotoxins vary widely, so their effects on human and animal health also vary widely. Mycotoxins may be classified according to the target organ as hepatotoxins, nephrotoxins, neurotoxins, immunotoxins, or according to their toxicological effects as cancerogen, genotoxic, mutagen, and teratogen. Among the “emerging” mycotoxins, toxins produced by various species of Alternaria are currently the focus of attention for the European Commission. Alternaria is one of the main fungi found on wheat, sorghum, and barley, and can also attack oilseeds such as sunflowers and rapeseed, as well as tomatoes, apples, citrus fruits, olives, and many other fruits and vegetables. Alternaria species produce more than 70 phytotoxins, some of which have been chemically characterized and reported as mycotoxins, known as Alternaria toxins (ATs). Some ATs, such as alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), and altertoxins (ATX) can induce harmful effects in animals, including fetotoxic and teratogenic effects. AOH and AME have been found to be mutagenic and clastogenic in different in vitro systems. Currently, there are no maximum permitted limits for the presence of ATs in food and feed, either at EU or global level. Recently, the European Commission issued Recommendation (EU) 2022/553, which highlights the urgent need to acquire further data on the toxicity and contamination of ATs in food.
This thesis evaluates the exposure of the Italian population to Alternaria toxins considering the contributions of two food matrices of high dietary relevance for the ATs contamination: tomato and hazelnuts. These commodities, consumed both fresh and processed, are particularly susceptible to fungal contamination under certain agronomic and storage conditions. The selection of these matrices is supported by official control data (2022–2024), which revealed positivity rates exceeding 20% for key Alternaria toxins, justifying a quantitative exposure analysis in line with EFSA recommendations.
To assess the estimated dietary intake (EDI) of the Italian population to Alternaria toxins, a deterministic approach was used. This method calculates exposure by combining ATs occurrence data in specific foods with the related consumption data and then dividing them by body weight. The occurrence data comes from the dataset of official national control plans and a series of data on tomato contamination obtained from analyses carried out during the study on samples collected on the market. Dietary intakes of the selected matrices and their derived products was obtained from Italian dietary surveys extracted from the EFSA's comprehensive database on European food consumption. To evaluate the impact on public health, a comparison between the assessed values obtained dietary exposures and the TTC was performed.
The exposure was estimated using conservative assumptions and considering the worst-case scenario for an estimate of high dietary exposure, by using the P95 of the Consumer only.
In accordance with the available occurrence data, three categories of tomato products and hazelnuts were selected. The results obtained show that, about the food matrices analyzed, the Italian population is exposed to Alternaria toxins. In fact, for AOH and AME, EDI P95 values exceed TTC in almost all tomato-based foods and in almost all age groups studied. In addition, the highest EDI values are observed in Infants, who, as is well known, have a significantly lower body weight value compared to adults, and a higher consumption rate per kg of body weight, again compared to adults. As regards TeA, the exposure scenario for tomato-based products is better but for hazelnuts the EDIs values at P95 exceed TTC for all age groups considered. A comparison was also made between the scenario involving the Total population and the scenario involving Consumers only. However, to make this comparison, given the limited availability of occurrence data, the EDI was calculated also by grouping all products into a single category (canned tomatoes). As expected, the EDIs values for Consumers only are always higher than the ones calculated for Total population; however, the scenarios for the tomato-based products are similar due to the fact that the consumption of canned tomatoes is quite widespread and there is therefore no marked difference in the number of consumers and non-consumers among the respondents of the consumption survey. In the case of TeA in hazelnuts, there is a difference between the EDI values calculated for the Total population and Consumers only, reflecting the lower consumption rates of hazelnuts in the Total population. It is important to emphasize that the data analyzed are limited, but the results obtained show that the Italian population is exposed to emerging Alternaria toxins. However, this study is in line with the requirements of Recommendation (EU) 2022/553 and provides useful information that can be incorporated into risk assessment processes. Of course, continuous efforts are needed to improve data availability to produce reliable food risk assessments. In fact, expanding risk characterization with a wider distribution of data allows for a more robust and meaningful risk assessment, improving the representation of the actual variability of exposure within the population.