On sufficient substantiation for maximum permissible level of zilpaterol in meat products

The Joint FAO/WHO Expert Committee recommends the maximum permissible level of zilpaterol in meat to be fixed at 0.5 µg/kg. This level is substantiated by results of analysis described in several research works. Nevertheless, substantiation provided for this recommended standard requires a detailed discussion. In this study, we aimed to analyze substantiation of FAO/WHO suggestions on the maximum permissible level (MPL) of zilpaterol in meat as per health risks for consumers. Our analysis of research results revealed that the no observed adverse effect level (NOAEL) and the lowest observed adverse effect level (LOAEL) were established allowing for negative effects on various organs and systems in the body. The lowest observed adverse effect level (LOAEL) under acute exposure was taken as a baseline for establishing MPL. This level produces negative effects on the nervous system (developing tremor). However, modifying factors used in MPL development have not been supported with solid argument. We also established that the LOAEL identified for the nervous system under acute exposure was much lower than NOAELs for other organs and systems under chronic exposure. Therefore, the aforementioned research results seem rather controversial. It is necessary to consider another additional factor, which is wide prevalence of cardiovascular diseases among adult population and risk factors that cause their development. Therefore, potential adverse effects on the cardiovascular system are no less important and we should note that they have been reliably detected both in acute and chronic experiments. In this study, we modeled a health risk caused by adverse effects of consuming meat products with residual zilpaterol levels; the risk was modeled in dynamics. The modeling experiment established that an impermissible health risk of adverse health outcomes in the cardiovascular system occurred even under exposure to zilpaterol in levels close to the lowest limit of sensitivity. Consequently, it seems rather premature to accept the maximum permissible level for zilpaterol in meat that is being suggested at present. It is recommended to cut its level down to the lowest limit of detection.