Semivolatile Organic Acids and Levoglucosan in New York City Air Following September 11, 2001

摘要

Organic acid compounds and levoglucosan, an important molecular marker of burning cellulose, were detected in New York City air samples collected between 9/26/01-10/24/01, 500 m from Ground Zero. The sampling of Ground Zero emissions at our site is commensurate with a southwesterly wind flow. Aerosol phase distributions captured with a High Capacity Integrated Organic Gas and Particle Sampler show many of the organic acids are semivolatile. However, underlying the phase equilibrium for certain acid molecules is a set of factors more complex than vapor pressure alone can explain. At our collection site, quartz filter acid concentrations by class follow predicted seasonal trends and are generally below the annual average and episodic concentrations determined earlier for urban Los Angeles. Here, analysis of distribution patterns of in-series acid homologues is consistent with a pyrogenic burden, the specifics of which are discussed. By evaluating the inorganic bulk chemistry of airborne PM-2.5 emissions from Ground Zero after 9/11/2001 with X-ray fluorescence, tentative assignments to sources of construction materials (flame-retardant, paint, cement, and polymer materials) are construed.