Abstract
The composition of ambient particulate matter (PM) and its sources were investigated at the Salton Sea, a shrinking saline lake in California. To investigate the influence of playa exposure on PM composition, PM samples were collected during two seasons and at two sites around the Salton Sea. To characterize source composition, soil samples were collected from local playa and desert surfaces. PM and soil samples were analyzed for 15 elements using mass spectrometry and X-ray diffraction. The contribution of sources to PM mass and composition was investigated using Al-referenced enrichment factors (EFs) and source factors resolved from positive matrix factorization (PMF). Playa soils were found to be significantly enriched in Ca, Na, and Se relative to desert soils. PMF analysis resolved the PM10 data with four source factors, identified as Playa-like, Desert-like, Ca-rich, and Se. Playa-like and desert-like sources were estimated to contribute to a daily average of 8.9% and 45% of PM10 mass, respectively. Additionally, playa sources were estimated to contribute to 38-68% of PM10 Na. PM10 Se concentrations showed strong seasonal variations, suggesting a seasonal cycle of Se volatilization and recondensation. These results support the importance of playas as a source of PM mass and a controlling factor of PM composition.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 8283-8292 |
| Number of pages | 10 |
| Journal | Environmental Science and Technology |
| Volume | 51 |
| Issue number | 15 |
| DOIs | |
| State | Published - Aug 1 2017 |
| Externally published | Yes |
Bibliographical note
Funding Information:We acknowledge the assistance of the Imperial Irrigation District staff who were crucial for logistical support and implementation of this project, as well as Andrew Robinson and Steve Bates (UCR, Department of Earth Sciences) who provided technical expertise regarding sample digestion techniques and ICP-MS analysis. This material is based upon work supported by UCR Regents' Faculty Development Award, USDA National Institute of Food and Agriculture, Hatch project Accession No. 233133, UCR Provost Research Fellowship, and the U.S. Geological Survey under Grant/ Cooperative Agreement Nos. G11AP20121 and G16AP00041. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Geological Survey. Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.
Publisher Copyright:
© 2017 American Chemical Society.