Distribution of H+ and Trace Metals in Ultrafine Ambient AerosolEPA Grant Number: R824791
Title: Distribution of H+ and Trace Metals in Ultrafine Ambient Aerosol
Institution: New York University
Current Institution: New York University Medical Center
EPA Project Officer: Chung, Serena
Project Period: October 1, 1995 through September 30, 1998
Project Amount: $589,560
RFA: Air Pollutants (1995) Recipients Lists
Research Category: Air Quality and Air Toxics , Air
Description:There is a growing body of epidemiological data indicating consistent and coherent associations between ambient particulate matter (PM) and excess mortality and morbidity. Recent epidemiological evidence strongly suggests that ambient particle associated acidity is more closely correlated with total mortality than indices of total particulate mass. In addition, evidence is accumulating to support the hypothesis that the number of ultrafine acid particles, rather than ambient mass, is an important determining factor affecting lung injury.
Over 90% of all airborne particles are generally found in nuclei less than 50 nm in diameter. However, no data are currently available on the number concentration of acidic ambient ultrafine particles largely because there are no suitable methods for measuring this important quantity. We propose to develop a method to measure the number concentration of ambient acidic particles with d less than 50 nm. Ultra-thin metal film acidic particle detectors will be developed and calibrated. They will form the basis for a field sampling system (FSS) for nuclei mode particles and a personal acid aerosol monitor (PAAM) for ultrafine (d<100 nm) ambient acid particles. The personal monitor will be small and lightweight designed to be worn by an individual. The FSS will be designed to simultaneously sample ambient acid nuclei for evaluation of the metal content since metals can provide catalytic surfaces for reactive substances, both in air and in the lung. They also can serve as tracers to help identify sources.
Using an optimized prototype of a field-ready version, we will measure the distribution of H+ and trace metals in the nuclei mode of the ambient aerosol in various representative samples of the relatively clean regional background air in Tuxedo, NY, including air masses originating in three major upwind regions in the midwest, southeast, and eastern Canada.