Effect of workplace CO2 exposure limit levels on innate immune response to hog barn dust exposure

Details

• Personal Author:
  Bailey KL ; DeVasure JM ; Romberger DJ ; Schneberger D ; Wyatt TA
• Description:
  Introduction: Exposure to concentrated animal feed operation (CAFO) barn dusts has been shown to induce strong pro-inflammatory conditions in the lung, mediated by innate immune responses to organic dust. It has also been established that hypercapnia can induce changes in innate immunity in humans as well as animals. Given that elevated CO2 is a common feature of poorly ventilated barns, particularly in more northern climates, we examined the effect of both dust and CO2 on inflammation in the lungs of mice. Methods: Mice were instilled once nasally with 12.5% settled hog barn dust extracts and subsequently held at either ambient CO2 (400ppm) or at the OSHA/NIOSH TWA exposure limit (5000ppm) for 6 hr. Lung lavage and tissue were tested for several known pro-inflammatory cytokines (IL-6, KC) and immune surfactants (SP-A, SP-D). Arrays for chemokines (protein) and TLR pathway participants (mRNA) were also used to identify other targets of potential interest. Results: Significant elevations in IL-6 and KC at 5000 ppm CO2 in barn dust-exposed animals were observed. Interestingly, mRNA for SP-A and D were both significantly decreased with exposure to barn dust. While no cellular changes were apparent, chemokine array data revealed significant CO2-mediated differences in response to dust. In particular MIP-1g was dramatically increased in lungs by dust, with the effect being even more pronounced in combination with CO2. Conclusions: We conclude that hypercapnia can play a role in lung inflammation in poorly ventilated barn facilities, even at the OSHA-approved 8-hr exposure levels. We further show that MIP-1g is greatly increased in response to barn dust exposure, and further still to barn dust plus CO2, requiring future examination of the function and significance of this chemokine on lung inflammation in organic dust exposures. [Description provided by NIOSH]
• Subjects:
  Agriculture Carbon Dioxide Dust Immune System Laboratories Occupational Health Safety
• Keywords:
  Agricultural Workers Animal Husbandry Workers Carbon Dioxide Exposure Assessment Immune Reaction Laboratory Animals Organic Dusts
• ISSN:
  1073-449X
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Abstract or Summary
• Place as Subject:
  Nebraska ; OSHA Region 7
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  191
• NIOSHTIC Number:
  nn:20048546
• Citation:
  Am J Respir Crit Care Med 2015 May; 191(Abstract Issue):A1720
• Contact Point Address:
  D. Schneberger, University of Nebraska Medical Center, Omaha, NE
• Email:
  d.schneberger@unmc.edu
• CAS Registry Number:
  Carbon dioxide (CAS RN 124-38-9)
• Federal Fiscal Year:
  2015
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Performing Organization:
  University of Nebraska Medical Center - Omaha
• Peer Reviewed:
  False
• Start Date:
  20110901
• Source Full Name:
  American Journal of Respiratory and Critical Care Medicine
• Supplement:
  Abstract Issue
• End Date:
  20270831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:02ecdd86ef18657c829da65931242903808938acbb6daa46bdb20ddac65cac4c7043e4297c3c6f4370d73237a5f35d86026799e7061961f885678b32878e228d
• Download URL:
  https://stacks.cdc.gov/view/cdc/203278/cdc_203278_DS1.pdf
• File Type:
  [PDF - 17.39 KB ]