Air Today . . . Gone Tomorrow Article|
Characterization of the
Dust/Smoke Aerosol that Settled East of the World Trade Center (WTC) in Lower Manhattan
after the Collapse of the WTC 1 September 2001
Perspectives, July 2002
The explosion and collapse of the World Trade Center (WTC) was a catastrophic event that
produced an aerosol plume impacting many workers, residents, and commuters during the
first few days after 11 September 2001. Three bulk samples of the total settled dust and
smoke were collected at weather-protected locations east of the WTC on 16 and 17 September
2001; these samples are representative of the generated material that settled immediately
after the explosion and fire and the concurrent collapse of the two structures.
We analyzed each sample, not
differentiated by particle size, for inorganic and organic composition. In the inorganic
analyses, we identified metals, radionuclides, ionic species, asbestos, and inorganic
species. In the organic analyses, we identified polycyclic aromatic hydrocarbons (PAHs),
polychlorinated biphenyls, polychlorinated dibenzodioxins, polychlorinated dibenzofurans,
pesticides, phthalate esters, brominated diphenyl ethers, and other hydrocarbons. Each
sample had a basic pH. Asbestos levels ranged from 0.8% to 3.0% of the mass, the PAHs were
> 0.1% of the mass, and lead ranged from 101 to 625 µg/g.
The content and distribution of material
was indicative of a complex mixture of building debris and combustion products in the
resulting plume. These three samples were composed primarily of construction materials,
soot, paint (leaded and unleaded), and glass fibers (mineral wool and fiberglass). Levels
of hydrocarbons indicated unburned or partially burned jet fuel, plastic, cellulose, and
other materials that were ignited by the fire. In morphologic analyses we found that a
majority of the mass was fibrous and composed of many types of fibers (e.g., mineral wool,
fiberglass, asbestos, wood, paper, and cotton).
The particles were separated into size
classifications by gravimetric and aerodynamic methods. Material < 2.5 µm in
aerodynamic diameter was 0.88-1.98% of the total mass. The largest mass concentrations
were > 53 µm in diameter.
The results obtained from these samples
can be used to understand the contact and types of exposures to this unprecedented complex
mixture experienced by the surviving residents, commuters, and rescue workers directly
affected by the plume from 11 to 12 September and the evaluations of any acute or
long-term health effects from resuspendable dust and smoke to the residents, commuters,
and local workers, as well as from the materials released after 11 September until the
fires were extinguished.
Further, these results support the need to
have the interior of residences, buildings, and their respective HVAC systems
professionally cleaned to reduce long-term residential risks before rehabitation.
FAIR USE NOTICE
This article contains copyrighted material, the use of which has not always been
specifically authorized by the copyright owner. I am making such material
available in my efforts to advance understanding of democracy, economic,
environmental, human rights, political, scientific, and social justice issues,
among others. I believe this constitutes a 'fair use' of any such copyrighted
material as provided for in section 107 of the US Copyright Law. In accordance
with Title 17 U.S.C. Section
107, the material in this article is distributed without profit for research
and educational purposes.
Take me back to learn more