Risk assessment of heavy metals contamination in pork

Pork is an important part of the daily diet of the Chinese population, and its safety has attracted the attention of the government and consumers. This study aims to assess the degree of heavy metal pollution of pork in the Chinese market, and to study the preventive measures against the main factors of heavy metal pollution in the supply chain, so as to reduce the health risks associated with eating this type of meat. 126 previously published levels of heavy metals in Chinese pork were collected from www.cnki.net. The pollution index of lead, arsenic, cadmium and mercury in pork as calculated by using the single pollution index method was found to be less than 0.7, and the pollution level of each single heavy metal in pork was deemed to be at the safe level. Then the risk of heavy metals in pork for different consumer age groups was assessed by using the Target Hazard Quotient (THQ) and Incremental life cancer risk (ILCR). These criteria are based on the weights and dietary habits of Chinese residents. The results showed that the contribution rate of lead in pork to Total THQ (TTHQ) was 42.2%, which was higher than for any other heavy metals. At the same time, it can be concluded that the ILCR of arsenic in [2,4] age groups exceeded the maximum acceptable limit (1 × 10−4). Finally, the fault tree method was combined with the pork supply chain to comprehensively analyze the causes of heavy metal pollution in pork. The results show that the structural importance coefficient of strengthening government supervision and improving China's food safety standard system is 1, which is the key to prevent the occurrence of heavy metal hazards in pork in China. Furthermore, the lead pollution incidents which occurred in pork obtained from the Nanjing Farmers Market were used as example cases in order to show the feasibility of using the fault tree methodology. This study provides a scientific and advanced theoretical guidance for further strengthening the ability of pork safety risk assessment and to assess the risks associated with pork consumption.