25年来 ,在公共卫生部门的努力下铅暴露有了显著的下降。现在美国血铅水平平均值已降至 70年代测定水平的 2 0 %以下 ,但居住在大城市中心的一小部分人群仍处于高血铅水平的高危状态。本次研究资料表明 ,居住在洛山矶中南部 (该地区是加利福尼亚州最贫困地区之一 )的移民孕妇 ( Over the past 25 years, there has been a significant drop in lead exposure with the efforts of the public health sector. Now that the average blood lead level in the United States has dropped below 20% of the level measured in the 1970s, a small proportion of people living in metropolitan centers are still at high blood lead levels. The research data show that immigrant pregnant women living in central and southern Los Angeles (one of the poorest areas in California)