World Trade Center Aerosol Health Hazard

Left: Looking out the 2nd-floor windows of the offices of ESA at 26th & Capitol in Sacramento.

It's been a number of years since I went to dinner meetings of the Mother Lode Chapter of the Air and Waste Management Association, but Wednesday's dinner promised to be special: UC Davis' Dr. Thomas A. Cahill was going to give a talk: "Health Impacts Of World Trade Center Aerosol: Past, Present, and Predicted."


Dr. Thomas A. Cahill.

Dr. Cahill is California's leading authority on the aerosol component of California's air pollution. For the last three decades he has been in the thick of almost every controversial aspect of air pollution control on the West Coast. He has access to the world's best equipment and has the ear of the world's leading authorities on these questions.

Nevertheless, I have a kind of love-hate relationship with some of Dr. Cahill's work. A couple of years ago I had to study, in detail, a report produced by his group regarding air pollution in the Ports area of Los Angeles/Long Beach, and I was struck by the report's sloppiness. Data didn't support conclusions. To me, it looked like the report was written in haste, and I wondered whether other reports from his group had the same weakness.

But when you are the among the world's leading authorities, time is scarce, and the opportunities are many.

Tonight's talk was on a subject of great interest. I had not followed the troubles regarding health impacts from the smoldering World Trade Center, and wondered what that was all about.

Met a few people I hadn't seen in a while, including Austin Kerr.









Apparently the initial cloud of dust from the World Trade Center, while very dense, was fairly-coarse in nature. Apart from the very large amounts of dust (mostly powdered gypsum derived from dry wall present throughout the buildings), the dust posed no particular health hazard.

The trouble started when the heaps of burning, collapsed buildings started smoldering. The fires didn't go out till mid-December, 2001.

First, a fine concrete aerosol was released from the smoldering heaps. This fine aerosol could penetrate deep into the lungs, and was very caustic in nature (pH ~ 12) and produced WTC 'dry cough'. Much was worse, however, was an ultrafine sulfuric acid mist (of uncertain origin, but probably deriving from sulfur released from the cooking gypsum deep in the piles), which paralyzed the cilia lining the walls of the lungs' airways, and lead to scarring, and even deeper penetration of the concrete dust. This terrible one-two punch made the World Trade Center site, as well as anywhere in southern Manhattan where the plumes could reach, VERY HAZARDOUS for the purposes of breathing: far worse than any urban aerosol, anywhere. But the danger was not appreciated at first, and thousands of workers were being sent on-site with little, or no breathing protection.

Several days after 9/11, the Bush Administration (specifically the Office of Inspector General) deemed that health issues at the World Trade Center site were regulatory in nature. That meant no special monitoring was to be allowed and that EPA and other government scientists would not be permitted to make measurements there. Being associated with UC Davis, Dr. Cahill had greater freedom-of-action and better equipment than his colleagues located more-closely; say, at Columbia University. Dr. Cahill and colleagues were able to quickly start making measurements, and start sounding the alarm. On their own money and time, brave government scientists began their own guerilla air quality monitoring too, and became alarmed as well. But since the matter was now of special interest to the Bush Administration, which was eager to project an image of normalcy in NYC after 9/11, and thus deprive Al Qaeda of a propaganda victory, these efforts to raise an alarm met active opposition from our own government. And meanwhile, thousands of WTC workers were being led to debilitating and early deaths.

I asked why litigation and legislation was required to support ailing WTC workers when all such matters were supposed to be addressed by Ken Feinberg and his special fund. Cahill answered that Feinberg's efforts were to be directed to the families and estates of the dead; Congress had not foreseen this workplace hazard, and no particular support was available for the WTC workers. It's ironic how hard we make life for the ailing, and how well we treat the dead!

Dr. Cahill emphasized the importance of living in California, where there are lots of NGOs (Non-Government Organizations) present to keep an eye on Big Government. When Big Government is the only game around (like in many states, and many nations) alarms don't get sounded in time.

I am curious how this matter would have looked to the people in the Bush Administration. Dr. Cahill cast the story as a sort of David-vs.-Goliath struggle, but, as they say, every story has two sides, and I'm sure Goliath has his own interpretation.

Here is a delightful article in the April, 2007 issue of Esquire Magazine regarding Dr. Cahill and his WTC efforts. A taste:

With this device, he has produced some of the most respected studies on the air quality after September 11, including an explosive 2003 report that concluded the smoldering debris pile acted like a chemical "incinerator." With this finding, Cahill confuted the EPA's early dismissal of the plume as an "irritant" and its ultimate conclusion about the air in lower Manhattan: "It is not a problem for the general population."

"Someone told me my report ended up on Bush's desk," says Cahill. "Supposedly, he had a cow."