## 3 Results and Discussion
### Carcinogenic Risk Assessment of Aflatoxin M1 Exposure  
To enhance the assessment of carcinogenic risk associated with chronic exposure to AFM1 through CM, an MCS involving 10,000 iterations was conducted. The simulation utilized a triangular distribution characterized by the minimum (0.02 \(\upmu\)g/L), mean (1.26 \(\upmu\)g/L), and maximum (7.62 \(\upmu\)g/L) concentrations of AFM1 observed in the CM. The findings indicated that all age demographics exhibited significant values for the CRI, with the highest mean CRI noted in children aged 1-2 years (7.92 \(\times\) 10\({}^{3}\)) and 3-4 years (5.07 \(\times\) 10\({}^{3}\)). The P95 values surpassed the internationally recognized threshold of 1 \(\times\) 10\({}^{4}\) across all age groups, suggesting that a considerable segment of the population may encounter an elevated cancer risk throughout their lifetime due to chronic exposure to AFM1 via CM consumption. The comprehensive results, encompassing mean, P95, and maximum CRI values for each demographic group, are illustrated in Table 2.  
Incorporating probabilistic modeling via MCS enhanced the authenticity of the risk analysis by considering inherent variability and uncertainty in both contaminant exposure \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Age Group** & **Mean** & **P95** & **Max** \\ \hline
1–2 & 7.92 \(\times\) 10\({}^{3}\) & 1.57 \(\times\) 10\({}^{2}\) & 3.17 \(\times\) 10\({}^{2}\) \\ \hline
3–4 & 5.07 \(\times\) 10\({}^{3}\) & 1.02 \(\times\) 10\({}^{2}\) & 2.06 \(\times\) 10\({}^{2}\) \\ \hline
5–9 & 3.56 \(\times\) 10\({}^{3}\) & 7.16 \(\times\) 10\({}^{3}\) & 1.45 \(\times\) 10\({}^{2}\) \\ \hline
10–19 & 2.12 \(\times\) 10\({}^{3}\) & 4.29 \(\times\) 10\({}^{3}\) & 8.68 \(\times\) 10\({}^{3}\) \\ \hline
20–59 & 1.47 \(\times\) 10\({}^{3}\) & 2.97 \(\times\) 10\({}^{3}\) & 6.01 \(\times\) 10\({}^{3}\) \\ \hline \hline \end{tabular} \(>\)60 \(\times\) 1.72 \(\times\) 10\({}^{3}\) 3.46 \(\times\) 10\({}^{3}\) 6.93 \(\times\) 10\({}^{3}\)  
CRI: carcinogenic risk index; P95: percentile 95; Max: maximum value.  
\end{table} 
Table 2: Carcinogenic risk index. Figure 2: Quantification and identification of AFM1 by liquid chromatography in commercial milk. AFM1 \(\upmu\)g/L: micrograms per liter of aflatoxin M1; A–W: cow’s milk; # indicates a statistically higher value compared to samples analyzed; * indicates a statistically lowest value compared to the samples. The red horizontal line indicates the maximum limit set by the Mexican standard NOM-243-SSA1-2010 (0.5 \(\upmu\)g/L). and population attributes. This methodology is consistent with contemporary guidelines from the EFSA (2020) and other global organizations endorsing distribution-based risk assessment models for evaluating carcinogenic mycotoxins [10]. The finding that children under five presented CRI values far exceeding the reference threshold (1 \(\times\) 10\({}^{4}\)) is particularly concerning. Additionally, even adult and elderly groups showed elevated CRI levels, though to a lesser extent, indicating that this issue affects the population more broadly. This analysis employed a CSF of 0.04 ug/kg bw/day, as proposed by [PERSON] (1990) and subsequently reaffirmed by the EFSA (2020) [10; 38]. Given the structural and toxicological similarity of AFM1 to AFB1, this parameter was essential for estimating lifetime cancer risk [3]. The CRI values derived from this study are congruent with earlier research that has evaluated the cancer risks associated with AFM1 [65; 66; 67; 68]. A probabilistic analysis in Hungary estimated chronic exposure to AFM1 in toddlers using a two-dimensional MCS [69]. The results indicated exposure levels of up to 3.79 \(\times\) 10\({}^{3}\) ug/kg bw/day at the 97.5 percentile, accompanied by a hazard index >1, which signifies a non-negligible health risk for this age demographic. Similarly, a study conducted in Monterrey, Mexico, identified AFM1 in 100% of breast CM, with average concentrations measuring 1.70 \(\times\) 10\({}^{2}\) ug/L.