« Previous AbstractCommon promoter elements in odorant and vomeronasal receptor genes    Next AbstractThe Ecological Significance of Aphid Cornicles and Their Secretions »

Environ Sci Technol

Title:		Home is Where the Pipeline Ends: Characterization of Volatile Organic Compounds Present in Natural Gas at the Point of the Residential End User
Author(s):		Michanowicz DR; Dayalu A; Nordgaard CL; Buonocore JJ; Fairchild MW; Ackley R; Schiff JE; Liu A; Phillips NG; Schulman A; Magavi Z; Spengler JD;
Address:		"Harvard T.H. Chan School of Public Health, C-CHANGE, Boston, Massachusetts 02215 United States. PSE Healthy Energy, Oakland, California 94612, United States. Atmospheric and Environmental Research (AER), Lexington, Massachusetts 02421, United States. Home Energy Efficiency Team (HEET), Cambridge, Massachusetts 02139, United States. Gas Safety Inc., Southborough, Massachusetts 01772, United States. Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02215, United States. Boston University, Boston, Massachusetts 02215, United States"
Journal Title:		Environ Sci Technol
Year:		2022
Volume:		20220628
Issue:		14
Page Number:		10258 - 10268
DOI:		10.1021/acs.est.1c08298
ISSN/ISBN:		1520-5851 (Electronic) 0013-936X (Print) 0013-936X (Linking)
Abstract:		"The presence of volatile organic compounds (VOCs) in unprocessed natural gas (NG) is well documented; however, the degree to which VOCs are present in NG at the point of end use is largely uncharacterized. We collected 234 whole NG samples across 69 unique residential locations across the Greater Boston metropolitan area, Massachusetts. NG samples were measured for methane (CH(4)), ethane (C(2)H(6)), and nonmethane VOC (NMVOC) content (including tentatively identified compounds) using commercially available USEPA analytical methods. Results revealed 296 unique NMVOC constituents in end use NG, of which 21 (or approximately 7%) were designated as hazardous air pollutants. Benzene (bootstrapped mean = 164 ppbv; SD = 16; 95% CI: 134-196) was detected in 95% of samples along with hexane (98% detection), toluene (94%), heptane (94%), and cyclohexane (89%), contributing to a mean total concentration of NMVOCs in distribution-grade NG of 6.0 ppmv (95% CI: 5.5-6.6). While total VOCs exhibited significant spatial variability, over twice as much temporal variability was observed, with a wintertime NG benzene concentration nearly eight-fold greater than summertime. By using previous NG leakage data, we estimated that 120-356 kg/yr of annual NG benzene emissions throughout Greater Boston are not currently accounted for in emissions inventories, along with an unaccounted-for indoor portion. NG-odorant content (tert-butyl mercaptan and isopropyl mercaptan) was used to estimate that a mean NG-CH(4) concentration of 21.3 ppmv (95% CI: 16.7-25.9) could persist undetected in ambient air given known odor detection thresholds. This implies that indoor NG leakage may be an underappreciated source of both CH(4) and associated VOCs"
Keywords:		*Air Pollutants/analysis Benzene Environmental Monitoring/methods Natural Gas *Volatile Organic Compounds Btex cooking fossil fuels hazard identification hazardous air pollutants natural gas leak odorants;
Notes:		"MedlineMichanowicz, Drew R Dayalu, Archana Nordgaard, Curtis L Buonocore, Jonathan J Fairchild, Molly W Ackley, Robert Schiff, Jessica E Liu, Abbie Phillips, Nathan G Schulman, Audrey Magavi, Zeyneb Spengler, John D eng Research Support, Non-U.S. Gov't 2022/06/29 Environ Sci Technol. 2022 Jul 19; 56(14):10258-10268. doi: 10.1021/acs.est.1c08298. Epub 2022 Jun 28"