Whitman assured the public that the air was safe before testing was conclusive. In addition, all EPA statements were required to be screened by the White House.

翻译为：惠特曼向公众保证在测试下结论之前空气是安全的。而且，所有的EPA（美国环保署）申明都要求经过白宫的筛选。

注意的词语：screen：动词，筛选/过滤。