The Contribution of Biomass Combustion to Ambient Fine Particle Concentrations in the United States

EPA Grant Number: R826233
Title: The Contribution of Biomass Combustion to Ambient Fine Particle Concentrations in the United States
Investigators: Cass, Glen
Current Investigators: Cass, Glen , Fine, Philip M. , Seinfeld, John
Institution: California Institute of Technology
EPA Project Officer: Shapiro, Paul
Project Period: February 1, 1998 through January 31, 2001
Project Amount: $532,642
RFA: Ambient Air Quality (1997) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Air


The objective of this study is to quantify the contribution of biomass combustion sources to atmospheric fine particle concentrations throughout most of the United States. Both the spatial and seasonal variation of biomass smoke concentrations will be determined.


This objective can be met through the use of newly developed organic chemical tracer techniques applied to biomass smoke source samples and to atmospheric fine particle samples. A series of field experiments involving source sampling, laboratory organic chemical analysis of source and atmospheric samples combined with air quality model development is proposed. First, those biomass combustion source types that account for approximately 90% of biomass smoke generation will be estimated via construction of a national emission inventory based on existing source activity and emission rate data. Then a source test program will be undertaken in which Caltech's dilution source sampling system will be used to measure the fine particle mass emission rate, particle elemental composition, particulate organic composition and particulate size distribution. Sources types to be tested include the obvious major contributors (fireplace combustion of wood, wood stoves, prescribed burns and forest fires) as well as any of the less obvious biomass sources that are found to be important (cigarette smoke, charcoal production, refuse incineration, agricultural waste disposal, etc.). Organic chemical fingerprints specific to the most important combinations of combustor type and fuel type will be determined by GC/MS analysis of the source samples. Atmospheric fine particle samples representative of a full year of sampling at approximately 80 to 100 sites across the United States will be analyzed by GC/MS to measure the ambient concentrations of biomass tracer compounds (e.g. thermally altered resin acids; syringol and guaiacyl-type compounds; plant waxes, etc.). Then air quality models will be applied that employ those chemical tracers to calculate, based on the source signatures, the contribution of biomass smoke to atmospheric fine organic aerosol and atmospheric fine particle mass concentrations. The spatial and seasonal distribution of the biomass smoke concentrations then will be mapped across the United States based on the air quality modeling results at the many air monitoring stations studied.

Expected Results:

Smoke from biomass combustion is one of the largest yet least well characterized contributors to atmospheric fine particle levels. Biomass combustion sources are believed to contribute 14 to 30% of the fine particle concentrations in cities, account for 16% of the national inventory of fine particle emissions and account for more than half of the non-fugitive dust primary fine particle emissions nationally. But because these emissions often occur from largely unregulated area-wide sources a clear nationwide picture of biomass smoke concentrations in the atmosphere is not presently available. The proposed study will deliver: (1) detailed, accurate, source profiles for biomass combustion sources that describe emission rates, particle composition and particle size, (2) characterization of the atmospheric concentration of biomass organic chemical tracer compounds across the nation, (3) air quality modeling methods for biomass smoke based on organic chemical tracers and (4) a knowledge of the spatial and seasonal distribution of biomass smoke over much of North America. The information to be created by this research is critical to the future development of air quality management plans for attainment of the proposed national ambient air quality standard for fine particles.

Publications and Presentations:

Publications have been submitted on this project: View all 12 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 6 journal articles for this project

Supplemental Keywords:

biomass, combustion, ambient air, particulate, organics, environmental chemistry, engineering measurement methods, entire United States., RFA, Scientific Discipline, Air, particulate matter, Environmental Chemistry, Environmental Monitoring, ambient air quality, particulates, air toxics, chemical characteristics, fine particles, ambient measurement methods, biomass combustion, smoke concentrations, seasonal variation, organic chemical trace techniques, incineration

Progress and Final Reports:

  • 1998 Progress Report
  • 1999
  • Final Report