Real-Time Detection of Particulate Chemical Composition near Agricultural Facilities Using Mass Spectrometry.

Agricultural facilities are the source of many types of particles and gases that can exhibit an influence on air quality.  Emissions potentially impacting air quality from agricultural sources have become a concern for various state and federal regulatory agencies. Particle mass concentration influences from agricultural sources can include both primary particles (direct emissions such as dust) and secondary particles (formed from gaseous precursors such as ammonia).

Continuous measurements of particulate size and composition were obtained via an aerosol mass spectrometer at several different producers. A single trailer equipped with an aerosol mass spectrometer for real-time acquisition of particulate chemical composition, including ammonium salts and carbonaceous material. Other instruments utilized for understanding aerosol distributions included a PM_2.5 carbon analyzer, optical particle counters, and an eight-stage cascade impactor. This suite of instrumentation allowed characterization of a wide range of particulate properties.

We find that most of the fine particulates in the area of these facilities are composed of regional background aerosol rather than primary emissions from the facilities. In the coarse mode, larger influences are observed from local primary emissions.