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February 13, 2002 email interchange between Thurston, USGS, and Jenkins

On 2/13/02 I emailed Dr. Thurston because I was upset over his 2/11/02 Senate testimony claiming the smaller W TC dust particles were not caustic. I expressed disbelief, profferi ng the alternative hypothesis that the larger surface area to mass of the smaller particles could well explain any discrepancy between their lower pH (lower alkalinity) result s. During sample storage prior to testing, moisture in the atmosphere could c ollect on the smaller particles, react and neutralize them. I also emailed my hypothesis to Dr. Geoff Plumlee, the U.S. Geological Service (USGS) scientist responsible for the initial pH testing of WTC dust after the disaster, wherein universally high corrosive pH levels were found.

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He also was concerned about the aging of the smaller WTC particles and their neutralization prior to any opportunity for testing by NYU. Dr. Thurston referred my inquiry to Dr. Lung Chi Chen at NYU, who wa s the scientist actually responsible for the pH tes ting. Dr. Chen did not admit in his email to me that he neutralized the smaller PM2.5 particles by the saline solution "lyophilization" technique. The following are excerpts from this email interchange. This interchange is important in establishing that Dr. Chen was extremely aware of the issue being presented to him both by Dr. Plumlee and myself, namely the selective ne utralization of the smaller particles prior to any opportunity for pH analysis. But he was completely sil ent on the fact that his laboratory had also observed this same phenomena, beca use they had artificially neutralized the smaller particles, but not the larger ones, prior to any pH testing.

_____________________ __________________________ _____________ _____________________ __________________________ _____________ Cate Jenkins 02/13/02 12:08 PM To: thurston@env.med. nyu.edu Subject: Questions on your pH measurements - - - - - - - - - - - - - - - - - - - - - - - - George, I have another question for your that I am sure you can clear up, in the never-ending battle to clarify hearsay: You are quoted as saying at the 2/11 hearing that in your studies you measured the pH of WTC dusts. You fractionated the dust into smaller, respirable-size particulates, and found that the smaller particles did not have a high pH (a high pH meaning alkaline or caustic). Considering the high surface to mass ratio of the small particulates, wouldn’t you be concerned that the high pH would quickly be neutralized by the moisture in the air? The cause of the high pH would be the presence of calcium carbonate without any moisture content (anhydrous calcium carbonate), created by the extremely high temperatures of the fires burning in the collapse of the WTC. My questions would be as follows: 1. How long was it from the time of generation (time the dust was deposited on the ground directly after being in the dust cloud) to the time of analysis? 2. Under what conditions were the samples maintained to preserve their anhydrous state? 3. Were WTC samples subjected to vacuum extraction and storage with a strong dessicant prior to analysis if in fact they were collected almost instantaneously from the time of deposition from any smoke or dust plume? 4. Were any experiments performed where the smallest particles of WTC dusts were re-subjected to temperatures comparable to the fires at the WTC to return them to their alkaline state, which would be more similar to what their pH was at the time they were in the dust cloud and inhaled by firefighters and police officers?

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St. Louis Post-Dispatch (2/9/02) Caustic dust blankets World Trade Center area

http://www.nye nvirolaw.org/PDF /StLouisDispatch-2-9-02 -Caus ticDustBlanketsW TCa rea.pdf