Date of Degree
MS (Master of Science)
Thomas M. Peters
First Committee Member
Nicole M Grosland
Second Committee Member
T. Renee Anthony
A Dylos DC1100 was evaluated to: 1. Establish relationship between low-cost DC1100 and higher-cost pDR 1200; 2. Develop a method to convert DC1100 particle number into mass concentration to compare with respirable and inhalable mass references.
A Dylos DC1100 was deployed in a swine CAFO, along with a pDR-1200 and filter set to collect respirable and inhalable particles. Deployment was conducted from December 2013 through February 2014 in 24 hour intervals. The pDR-1200 and respirable mass concentration was used to convert the DC1100 particle count to mass concentration. Two methods of conversion were used, physical property method (Method 1) and regression method (Method 2).
Direct measurements from the DC1100 and pDR-1200 had a coefficient of determination (R2) of 0.85. DC1100 particle number were converted to mass concentration using Method 1 and Method 2, the coefficient of determination (R2) was 0.72 and 0.73, respectively compared to pDR-1200. The slope of the best-fit line was 1.01 for Method 1 and 0.70 for Method 2. When the DC1100 daily averages were compared to respirable mass, the physical property method had an R2 of 0.64 and a slope of 1.10. Regression method had an R2 of 0.62 and a slope of 0.80. Both methods underestimated inhalable mass concentrations with slopes < 0.13.
The Dylos DC1100 can be used to estimate respirable mass concentrations within a CAFO. Using expensive dust monitors to correct the number of particles into a mass concentration is needed to establish a correction factor for the DC1100. Using these methods, correction factors can be determine for many occupational environment, with the physical property method being preferred over the regression method.
A low-cost dust monitor (Dylos DC1100, $200) was tested to determine if it can be a suitable replacement for dust sampling in a swine concentrated animal feeding operation (CAFO). The DC1100 was sampled in the swine CAFO during the winter along with a higher-cost sensor ($5,800) and filters to collect the dust. Two methods for converting DC1100 information into mass concentrations were developed. Statistical tests were run on the comparison of devices using both methods for converting the DC1100. The first method was a good estimation of mass concentrations, while the second method underestimated mass concentrations when comparing to both the higher-cost sensor and the filters. The DC1100 and higher-cost sensor responded to changes in dust concentrations similarly, both in scale of the response and response time. It was concluded that using the DC1100 low-cost dust monitor could be used in a swine CAFO.
publicabstract, Aerosol, CAFO, Dylos, Low-Cost, Occupational Exposure, Swine
ix, 143 pages
Includes bibliographical references (pages 141-143).
Copyright 2015 Samuel M. Jones
Jones, Samuel M.. "Evaluation of a low-cost aerosol sensor to assess occupational exposures." MS (Master of Science) thesis, University of Iowa, 2015.