| Title: | Volatile organic compound emissions from dairy cows and their waste as measured by proton-transfer-reaction mass spectrometry |
| Author(s): | Shaw SL; Mitloehner FM; Jackson W; Depeters EJ; Fadel JG; Robinson PH; Holzinger R; Goldstein AH; |
| Address: | "Department of Environmental Science, Policy, and Management, University of California, Berkeley, Hilgard Hall, Berkeley, California 94720, USA. slshaw@alum.mit.edu" |
| ISSN/ISBN: | 0013-936X (Print) 0013-936X (Linking) |
| Abstract: | "California dairies house approximately 1.8 million lactating and 1.5 million dry cows and heifers. State air regulatory agencies view these dairies as a major air pollutant source, but emissions data are sparse, particularly for volatile organic compounds (VOCs). The objective of this work was to determine VOC emissions from lactating and dry dairy cows and their waste using an environmental chamber. Carbon dioxide and methane were measured to provide context for the VOCs. VOCs were measured by proton-transfer-reaction mass spectrometry (PTR-MS). The compounds with highest fluxes when cows plus waste were present were methanol, acetone + propanal, dimethylsulfide, and m/z 109 (likely 4-methyl-phenol). The compounds with highest fluxes from fresh waste (urine and feces) were methanol, m/z 109, and m/z 60 (likely trimethylamine). Ethanol fluxes are reported qualitatively, and several VOCs that were likely emitted (formaldehyde, methylamine, dimethylamine) were not detectable by PTR-MS. The sum of reactive VOC fluxes measured when cows were present was a factor of 6-10 less than estimates historically used for regulatory purposes. In addition, ozone formation potentials of the dominant VOCs were -10% those of typical combustion or biogenic VOCs. Thus dairy cattle have a comparatively small impact on ozone formation per VOC mass emitted" |
| Keywords: | Air Pollutants/*analysis Animals Carbon Dioxide/analysis *Cattle Environmental Monitoring Female *Lactation Manure/analysis Mass Spectrometry/methods Organic Chemicals/*analysis Ozone/*chemistry Pregnancy Protons Volatilization; |
| Notes: | "MedlineShaw, Stephanie L Mitloehner, Frank M Jackson, Wendi Depeters, Edward J Fadel, James G Robinson, Peter H Holzinger, Rupert Goldstein, Allen H eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2007/06/28 Environ Sci Technol. 2007 Feb 15; 41(4):1310-6. doi: 10.1021/es061475e" |
