在法制管理中,一个较大的困难是如何使潜在的有毒物质的危险性等于“零”。分析化学已使“零”的概念变得越来越小,但毒理学却无法跟上步伐。毒理学家无法说明膳食中低到几个微克的毒性物质对人类健康有什么样的影响,面对这种情况,FDA将如何对待那些含量仅为ppb级的有毒物质呢? Rulis博士和他在FDA的同事对这些问题,特别针对那些间接添加剂(上万种包装材料的溶出杂质)都进行了深入的研究。他们认为事实上存在一个“政策阈值”,即当溶出杂质低于某一浓度时,其对健康的危害将很 One of the major difficulties in legal management is how to make the risk of potentially toxic substances equal to zero. Analytical chemistry has made the concept of “zero” smaller and smaller, but toxicology can not keep up. Toxicologists can not explain how low to a few micrograms of toxic substances in a meal affect human health. In the face of this situation, how FDA treats toxic substances at levels as ppb? Rulis and his FDA colleagues conducted an in-depth study of these issues, especially those indirect additives (dissolution impurities on thousands of packaging materials). They think there is a “policy threshold” in fact that when the impurities are dissolved below a certain concentration, their health hazards will be very