2006 - 2008

Activity-specific workplace exposures of poultry barn workers

Principal Investigator: A. (Sentil) Senthilselvan, University of Alberta
Co-investigator: Irene Wenger, Nicola Cherry, John Feddes, Jerry Beach, University of Alberta
Status: Completed


There are relatively few data available on the exposure of poultry workers to environmental contaminants. The purpose of this study was to log the amount of time poultry workers spend on various activities on farm and to measure their exposure to environmental contaminants (respirable dust, ammonia, CO2). Exposures were compared between layer and broiler operations throughout production cycles at different times of the year.

Research Progress

During a previous study, poultry workers completed questionnaires designed to determine the amount of time they spent on various farm activities. Workers were also fitted with Personal Environmental Sampling Backpacks to measure contaminant (dust, ammonia, relative humidity, carbon dioxide) exposure during these activities. In all, there were 17 layer operations and 16 broiler operations visited. Broiler farm visits occurred at different times of the year and layer visits occurred at various stages of the flocks’ production cycles. Data from point exposures were linked to activity diaries to estimate total exposures for the workers. Dust (less than 10µm) levels overall were higher in broiler barns than in layer barns. There was no season difference in dust levels in the broiler barns, but they were higher in the layer barns during the winter than the summer. Relative humidity (RH) was generally higher in broiler barns than layer. There was no season difference in RH in the broiler barns, but it was higher in the layer barns in the summer than in the winter. Carbon dioxide levels were higher in the broiler barns vs. layers, and were higher in the winter vs. summer for both types of operations. There was no season difference in temperature in the layer barns while the broiler barns were warmer in summer than in the winter. As the broilers aged, dust levels increased, but there were no changes in ammonia, CO2 or RH. There were no layer flock age effects on any of the contaminants measured. All stated objectives were met. In addition to the measurements outlined above, the project was intended to suggest measures to protect poultry workers from potential environmental health hazards. Surprisingly, the study suggests that ammonia exposures did not exceed the 25ppm Time Weighted Average Threshold Limit Value (the TLV of a chemical substance is a level to which it is believed a worker can be exposed day after day for a working lifetime without adverse health effects, according to the American Conference of Governmental Industrial Hygienists (ACGIH)). The authors did point out, however, that the sampling equipment used has a time lag and may have underestimated ammonia levels since the workers were in the barns for relatively short periods of time. Similar to ammonia, measured CO2 levels did not exceed the 5,000ppm TWA TLV. The authors do recommend that poultry workers use N95 or comparable respirators while working in their barns to mitigate adverse effects of respirable dust.


$33,726 (CPRC $11,242, NSERC/AAFC $22,484)


Kirychuk SP, Dosman JA, Reynolds SJ, Willson P, Senthilselvan A, Feddes JJ, Classen HL, Guenter W. Total dust and endotoxin in poultry operations: comparison between cage and floor housing and respiratory effects in workers. J Occup Environ Med. 2006 Jul;48(7):741-8. Wenger, I.I., Ouellette, C.A., Feddes, J.J.R., and Hrudey, S.E. 2005. The Design and Use of the Personal Environmental Sampling Backpack (PESB II) for Activity-Specific Exposure Monitoring of Career Pig Barn Workers. Journal of Agricultural Safety and Health. 11(3):315-324

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