Air Pollutant Source Attribution for Southeast Texas Using 14C/12C Ratios
Abstract
Both ambient air samples for VOC analysis and particulate matter samples were collected in the greater Houston area in an attempt to assess the biogenic contribution to the formation of ground-level ozone and particulate matter through the use of radiocarbon measurements. This effort was just a small portion of the many experiments conducted as a part of the Texas Air Quality Study (TEXAQS) 2000. In particular, this set of samples was collected in the time frame of early August 2000 to mid September 2000, when the TEXAQS program was at its most intensive point, with the intention of utilizing the many other sources of supporting and collaborative data that were created in that time period. Biogenic emissions play a substantial role as a source of particulate matter for two sampling sites in particular. The results from eleven samples, taken from a suburban site (Aldine) in northwest Houston and a rural site (Conroe) approximately thirty miles north of Houston, provide strong evidence of a significant fraction of the particulate matter collected being biogenic in origin. Values reported from Aldine fall into two distinct ranges of 25-37% biogenic or 46-68% biogenic. One sample from Conroe, dated 13 August 2000, has a biogenic fraction of 72%. All eleven samples were taken prior to a forest fire event that occurred during the TEXAQS period. Very little evidence was found for vegetative detritus as a source of organic carbon in any of the samples for which trace metal data are available. Little evidence of cooking emissions is seen in the trace metal analyses for two samples at Aldine (18 and 19 August), and only small contributions from cooking are expected for a 25 August sample.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2001
- Accession Number
- ADA390413
Entities
People
- Kenneth R. Lemire
Organizations
- University of Texas at Austin