George Thurston New York University School of Medicine P30ES00260
Background: In the aftermath of the World Trade Center attack and collapse, thousands of people were exposed to high concentrations of gaseous and particulate matter air pollution. This pollution resulted from the release into the atmosphere of millions of tons of pulverized and incinerated building materials, furniture, equipment, and unburned jet fuel. Many residents and emergency responders reported a persistent "World Trade Center cough" despite the pronouncements of safety by a variety of government agencies. This team provides a possible explanation for this disparity.
Advance: One property of the dust that is probably most responsible for its irritancy is its caustic nature. The pH of the bulk of the dust was greater than 10, which is irritating to the mucous membranes found in the nose and throat. The pH decreased as the size of the particles decrease to around neutral pH at 2.5 microns and smaller. The caustic large dust particles caused temporary nose, throat, and upper airway symptoms; however, they were effectively caught by the body's defenses. Conversely the fine dust that did reach the lungs was lower in concentration and much less caustic. Therefore, although severe acute symptoms were reported, the overall dust exposures probably will not have cumulative health implications for the general population in lower Manhattan.
Implication: The important public health lesson to be learned from this disaster is that government agencies should make wider assessments of exposure to different sizes of particles before making pronouncements as to the safety of situations. Although in this situation the agencies were apparently correct regarding the long-term safety of the exposures, premature assurances in light of a large number of people with a persistent cough may have tended to undermine rather than increase public confidence.
Citation: Chen LC, Thurston G. World Trade Center cough. Lancet. 2002 Dec;360 Suppl:s37-8.