Abstract
As a staple food for people worldwide, processed grain products, including rice, wheat flour, etc., have been the major source of the toxic element cadmium for human exposure. Indeed, cadmium contamination in processed grain products directly affects food security and human health, especially in countries with a grain-based diet like China. By analyzing the cadmium levels in processed grain products across 20 provinces and cities in China during the period 2023-2024, we have developed an improved k-means++ algorithm that determines the optimal clustering number through a voting scheme. This algorithm has enabled us to establish a risk classification model, which provides an objective and rapid assessment of risk levels based on data-driven analysis. The results of the risk classification reveal that the risk levels of cadmium contamination in processed grain products can be classified into five levels, with high-risk products accounting for only 2.81% of the total. As for different types of processed grain products, the risk levels of rice and other processed grain products are higher than that of wheat. In addition, the risk levels of southern provinces/cities in China are higher than those of northern provinces/cities.