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Occupational exposure to respirable particles released during environmental recycling of class b biosolids

Kevin G. Robinson, PhD, MSPH1, Carolyn H. Robinson, PhD, MPH, RN2, Moshiur Rahman1, and F. Ann Draughon, PhD3. (1) Civil & Environmental Engineering, University of Tennessee, 219A Perkins Hall, Knoxville, TN 37996, 865-974-0722, kgr@utk.edu, (2) College of Nursing, University of Tennessee, 1200 Volunteer Blvd., Knoxville, TN 37996, (3) Food Safety Center, University of Tennessee, Food Safety and Processing Building, Knoxville, TN 37996

Because airborne particles originating from Class B biosolids can potentially transmit enteric microorganisms and their irritants, there is growing concern within occupational and agricultural settings regarding potential direct exposure to these agents. This study is addressing occupational/agricultural exposure by quantifying airborne release of respirable particles containing pathogens and endotoxins during Class B biosolids processing and farmland application. Initial experiments were conducted at a local biosolids treatment facility. Breathing zone samples were collected, using Button samplers with appropriate filters, at two major processing locations and a background site. Results show that all three sites had similar, low level, endotoxin and fecal coliform concentrations signifying little contamination. The mass of material collected over the 90 min sampling period was less than 6 mg (at an air flow rate of 2 L/min) indicating that the moist biosolids generated during processing, coupled with the environmentally quiescent conditions during sampling, were not conducive to particle dispersion. It is anticipated that higher airborne levels of both endotoxin and fecal coliform will be generated at farm sites during mechanical dispersal of biosolids onto the soil. Therefore, samples will be collected during farmland application on a schedule that coincides with environmental conditions which maximize airborne dispersal of particles (such as high wind speed, high temperature and low humidity). The farm site research will focus on critical control points (transfer and spreading) for potential exposure to the target biological agents. At least four farm application sites will be sampled on two different days to quantify particle/bioagent dispersal.

Learning Objectives:

  • At the conclusion of the session, the participant in this session will be able to

    Presenting author's disclosure statement:
    I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.

    Occupational Health & Safety Topics: Poster Session

    The 132nd Annual Meeting (November 6-10, 2004) of APHA