A report released last week by the EPA's Inspector General found that the White House instructed EPA officials to reassure New Yorkers that air in the vicinity of Ground Zero was safe to breathe after the calamitous Sept. 11 attacks on the World Trade Center, even though EPA did not collect samples of pulverized concrete and glass particulate until ten to 15 days after the attack, and the results were not known until early October.

EPA initially monitored levels of asbestos, lead, PCBs, dioxins, various heavy metals and assorted chemicals specified in the Clean Air Act in downtown Manhattan and in Brooklyn, but not both large and fine particulates of ground concrete and glass that most concern physicians and researchers.

In tests conducted in May 2002, EPA scientists exposed mice to dust from Ground Zero. The mice developed respiratory ailments similar to those reported in people who lived and worked near Ground Zero. Thousands of New Yorkers have developed sensitivities that sometimes lead to shortness of breath, say public health officials.

The EPA report said the White House edited EPA press releases to add reassuring statements and delete cautionary statements.

White House officials countered the report's findings, saying decisions were made for reasons of national security.

Air quality has returned to normal in Manhattan and Brooklyn and poses no threat to public health, according to health officials.