Concurrence, packaging effects, and risks of short- and medium-chain chlorinated paraffins in commercial dairy products

Short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) are persistent organic pollutants that have potential adverse effects on the environment and human health. Animal-derived foodstuffs are generally considered the primary source of chlorinated paraffins (CPs) for human exposure. However, information on the levels of CPs in different categories of dairy products is lacking. Here, we present a comprehensive study on SCCPs and MCCPs in butter, cheese, milk tablets, modified milk, modified milk powder, sterilized milk, whole milk powder, and yogurt of cow milk origin sold in China. Lower CP concentrations were observed in high-moisture dairy products (e.g., sterilized milk, yogurt, and modified milk) compared with the other categories. CP concentrations in cheese were the lowest among the three categories of imported dairy products (butter, cheese, and modified milk powder). CPs in imported modified milk powder and cheese were higher than in the corresponding domestic products. Trace levels of CPs may migrate from packaging materials under prolonged storage conditions, although actual dietary contributions from packaging migration are minimal. Risk assessment indicated that the health threat posed by exposure to CPs through dairy product intake was low for the general population in China.