Pyroclastic clouds/dust

Matters in the Air

Pyroclastic clouds occur when large amounts of dense particulate material is suspended suddenly in air or volcanic gasses and concentrated in a defined area.






The suspension will then act as a separate, denser fluid that remains distinct as it moves through the less dense medium. This cloud can travel at great speed.

General description of pyroclastic clouds

http://en.wikipedia.org/wiki/Pyroclastic_flow

Article on the much finer particulates found later
Prof. Cahill on nano-particles

Environmental Health Perspectives (EHP)
A monthly journal of peer-reviewed research and news on the impact of the environment on human health.
Characterization of the Dust/Smoke Aerosol
http://www.ehponline.org/members/2002/110p703-714lioy/lioy-full.html

Jenny Orkin:
[World Trade Center Environmental Organization]
Photographs, articles & links.



400 00 lbs lead,
200 000 lbs asbestos, with glass, plaster, wood, carpet, fibreglass, plastic & 750 000 tons of concrete



Plus - Americium-241 (made by nuclear reactors, a decay product of plutonium-241 from thousands of smoke detectors)

Mostly pulverized or shredded into particulate mostly less than 100 microns in diameter moving fast in the confinement of tall buildings. Above, finer dust and smoke drifts across Manhattan: [More]

Wide range of photographs posted at 911research
http://911research.wtc7.net/wtc/evidence/photos/dust.html#north