许多材料证实,当环境污染物处在稳定状态时,长期生活在此环境中的人群或动物体内的污染物浓度几乎处于平衡状态。 为了探讨非职业性接触人群中血铅的正常水平,研究其影响血铅浓度的因素等。我们于1985年对南宁市中学教师血铅水平进行了研究。 一、材料与方法 1.确定供血者:本文采用不分层双阶整 Many materials confirm that when the environmental pollutants are in a steady state, the concentrations of pollutants in the population or animals that have lived in the environment for a long time are almost in balance. In order to explore the non-occupational exposure to the normal level of blood lead, to study the factors that affect the blood lead concentration. We studied the blood lead levels of secondary school teachers in Nanning in 1985. First, materials and methods 1. To determine the blood donor: This article uses non-hierarchical double order