Caustic dust health hazard report, Feb 2002

NYC 9/11 Public Portal Document

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Most of the samples taken by USGS' team had a pH of 9.5 to 10.5, about the same alkalinity as ammonia. Two samples that were taken inside a high-rise apartment and in a gymnasium across from the wreckage of the World Trade Center had a pH of 11.8 to 12.1 - equivalent to what would be found in liquid drain cleaner.

The degree of acidity or alkalinity in a material is expressed as a pH measurement. Neutral pH - like water - is 7 on a 15-point scale. Lower than 7, to 0, is an indication of acid. Higher than 7, to 14, the top of the scale, is alkaline. Levels near either end of the pH scale can harm the health of people and animals.

Bruce Lippy, Loewenherz's counterpart with the operating engineers union, is responsible for the 300 workers running heavy equipment at ground zero.

"Part of the dilemma we faced was not knowing precisely what was in the dust" Lippy said. 'We knew it was caustic but had no information on exactly how caustic it was. I was trying to get people to wear the respirators, but if I knew how high the pH levels were, I could have been more persuasive in convincing the workers of the dangers."

Only a handful of the 100 or so workers sorting wreckage and loading trucks on the site over three days last week were seen wearing respirators or protective masks.

Scientists rush to Manhattan

Like the rest of the world, the USGS team watched the storm of dust roll across Manhattan after the terrorist attack on Sept 11. With its world-class laboratories and sensors that can detect minerals on a distant planet, the Denver-based team was already making arrangements to get NASA's infrared sensors and aircraft over ground zero as the EPA and the U.S. Public Health Service requested its help.

Responding to requests from the White House science office, the NASA team flew over Manhattan four times between Sept. 16 and Sept. 23, while USGS scientists collected samples of the dust from 35 locations below.

Back in Denver, more than two dozen scientists using the world's most sophisticated analytical equipment ran the samples through extensive testing.

The Geological Survey's test results were posted Sept. 27 on a Web site restricted to government agencies.

The uses findings were "evaluated by our technical experts and found to be consistent with the findings of EPA's Office of Research and Development," said Bonnie Bellow, the agency's spokeswoman in New York.

'The USGS data was also discussed by an interagency group of scientists, epidemiologists and health officials," Bellow said.

But neither the EPA headquarters nor its New York office would comment on what came out of these discussions or which EPA results they were "consistent' with.

The USGS data on pH levels were not released by the EPA, nor apparently were the environmental agency's own test results on the dust

"It is extremely distressing to learn that the EPA knew how caustic samples of the dust were and didn't publicize the information immediately, or make sure that OSHA publicized it," said Joel Shufro, executive director of the New York Committee for Occupational Safety and Health.

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