Evaluation of pH, Microbial Contamination, and Aflatoxin M1 Levels in Raw Milk: A Health Risk Assessment

Abstract

Background: This research aimed to assess pH, microbial load, and aflatoxin (AF) M₁ levels in milk from cattle dairy farms and milk distribution and collection centers in Ilam province. Methods: In this study, a total of 84 raw milk samples from Ilam province, collected between April and June, were analyzed for total bacterial count (TBC), pH, and AFM₁ using high-performance liquid chromatography. Daily AFM₁ intake was calculated to assess health risks based on milk consumption, using different risk assessment indices. Results: The highest microbial load was found in farms Location 5 (7.84 log CFU/ml) and the lowest average microbial load was recorded in farms Location 4 (5.92 log CFU/ml), while collection centers showed an average microbial count of 5.48 log CFU/ml, also linked to Location 4. AFM₁ was found in 84 samples: 65 had levels below 20 ng/g, 17 ranged from 20 to 90 ng/g, and 2 exceeded 150 ng/g, surpassing safety standards. The analysis indicates that young children consuming milk may face health risks from AFM₁, notably liver cancer. The increased incidence of elevated liver cancer risk (LCR) and associated hazard index (HI) values in children under the age of seven necessitate the implementation of more stringent regulations regarding AFM₁ contamination in dairy products, specifically targeting this demographic. Conclusion: Although the risk of liver cancer declines with age, it is imperative to maintain vigilant monitoring of cumulative exposure to AFM₁. This is particularly important for older adults, who may represent a vulnerable population with heightened susceptibility to AFM₁-related health complications. Ensuring rigorous surveillance and enforcement of safety standards for aflatoxins levels in milk products is essential for protecting these at-risk groups from potential adverse health outcomes.