Development of a Continuous Monitoring System for PM10 and Components of PM2.5EPA Grant Number: R825305
Title: Development of a Continuous Monitoring System for PM10 and Components of PM2.5
Investigators: Lippmann, Morton
Institution: New York University Medical Center
EPA Project Officer: Hiscock, Michael
Project Period: October 1, 1996 through September 30, 1999
Project Amount: $436,262
RFA: Analytical and Monitoring Methods (1996) RFA Text | Recipients Lists
Research Category: Environmental Statistics , Air Quality and Air Toxics , Water , Land and Waste Management , Air , Ecological Indicators/Assessment/Restoration
Description:The objective of this research project is to develop continuous monitors for the concentrations of PM10, PM2.5, semivolatiles (organic compounds and NH4NO3), particle bound water, and other PM10 constituents that are considered to be likely causal factors for excess mortality and morbidity in U.S. communities. While PM10 (particulate matter < 10 ?m in aerodynamic diameter) is the index pollutant for the National Ambient Air Quality Standard (NAAQS) for PM. There is evidence for still closer epidemiological associations with indices of fine particles, such as fine particles with aerodynamic diameters < 2.5 ?m (PM2.5) and sulfate ion (SO4=). Furthermore, some experimental exposure-response studies suggest that the hydrogen ion (H+) and ultrafine (PM0.1) concentrations may be important risk factors. There is also good evidence for measurement artifacts in current methods used to measure ambient PM10 and PM2.5, including negative artifacts because of losses of sampled semivolatile components (ammonium nitrate and some organics) and positive artifacts due to particle-bound water.
The continuous monitoring system to be developed and validated in this research will aerodynamically sort PM10 into three size-fractions: 1) coarse mode (PM10-PM2.5); 2) accumulation mode (PM2.5-PM0.15); and 3) ultrafine mode (PM0.15). The mass concentration of each mode will be measured using either the new method of Koutrakis (linear relation between accumulated mass and pressure drop on polycarbonate pore filters), or by change in b-attenuation on a sampling filter. For the accumulation mode aerosol (PM2.5-PM0.15), which contains nearly all of the semivolatiles and particle-bound water by mass, system components will continuously monitor aerosol sulfate (by flame photometry), aerosol ammonium and aerosol nitrate (by chemiluminescence), aerosol organics (by thermal-optical), and particle-bound water (by electrolytic hygrometer after vacuum evaporation of sampled particles). The concentration of H+ will also be determined (by ion balance using the data on NO3-, NH4+, and SO4=).
Some of the monitoring system components include a flame-photometric detector (FPD), a dual channel chemiluminescent detector (CLD), PM10 inlets, 2.5 ?m virtual impactors, and miscellaneous pressure gauges, and electronic components. Other commercially available components will include a flame-ionization detector (FID), a He-Ne laser, the components needed to assemble the mass monitors, and miscellaneous solenoid valves, pumps and blowers, flowmeters, and hardware. For other essential components, we will design, fabricate, and evaluate new prototype equipment based on established principles. This category includes the 0.15 ?m virtual impactor, the type mass monitor for PM0.15, and the system to measure particle-bound water. The entire system, after development, component validation, and calibration will undergo field trials at: 1) our laboratory in midtown Manhattan; and 2) our laboratory in Tuxedo, NY, a relatively clean air site 50 miles NNW of Manhattan. Based on our laboratory and field experience, we will specify the design criteria for second generation continuous monitors for research and routine monitoring applications.