Citation:

Vallero, D A. CURRENT AND EMERGING TECHNIQUES FOR CHARACTERIZING TROPOSPHERIC AEROSOLS. Presented at Mechanics in the Environment Seminar, Durham, NC, September 1, 2004.

Impact/Purpose:

1) Develop methods of ecological exposure (e.g. rapid , sensitive analytical screening methods for a select list of antibiotics widely used in agriculture primarily in CAFOs (confined animal feeding operations).

2) Do Measurements & Provide data for multicompartment models of fate and transport.

3) Study biomagnification of specific chemicals and toxic metals.

4) Study specific pharmaceuticals:

*Determine the routes of entry and the impact of environmental factors such as rainfall on the movement and survivorability of selected antimicrobials in the environment.

*Determine if the entry of agriculture based antibiotics into the environment contributes to resistance in bacterial populations.

*Determine the contribution from municipal waste water treatment plants to antibiotic loading in the environment.

5) Develop methods for the analysis of alkylphenol ethoxylates and derivatives.

Description:

Particulate matter generally includes dust, smoke, soot, or aerosol particles. Environmental research addresses the origin, size, chemical composition, and the formation mechanics of aerosols. In the troposphere, fine aerosols (e.g. with diameters < 2.5 um) remain suspended until aggregation, agglomeration or flocculation to form larger particles, leading to sedimentation and deposition. Aerosols are often hygroscopic nuclei that attract water vapor and form droplets. The finer suspended particles are human health hazards, since once breathed into the lungs, they are trapped and remain there to cause a number of respiratory problems. The ability to measure and to characterize aerosols has been evolving, so that numerous methods are presently available. However, several challenges remain; including improved gravimetric for very small particles (< 1 um) and optical techniques for small particles (< 2.5 um), real-time and on-line measurements of chemical composition (e.g. single particle mass spectrometry), and means for enhanced precision and accuracy (e.g. decreased losses in sampling apparatus, including pressure drops, particle bounce, and chemical reactions on filters, as well as remote and portable measurement and analytical capabilities).

Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

Record Details: