Widespread natural perchlorate in unsaturated zones of the southwest United States
A substantial reservoir (up to 1 kg ha-1) of natural perchlorate is present in diverse unsaturated zones of the arid and semi-arid southwestern United States. The perchlorate co-occurs with meteoric chloride that has accumulated in these soils throughout the Holocene [0 to 10−15 ka (thousand years ago)] and possibly longer periods. Previously, natural perchlorate widely believed to be limited to the Atacama Desert, now appears widespread in steppe-to-desert ecoregions. The perchlorate reservoir becomes sufficiently large to affect groundwater when recharge from irrigation or climate change flushes accumulated salts from the unsaturated zone. This new source may help explain increasing reports of perchlorate in dry region agricultural products and should be considered when evaluating overall source contributions.
Citation Information
Publication Year | 2007 |
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Title | Widespread natural perchlorate in unsaturated zones of the southwest United States |
DOI | 10.1021/es062853i |
Authors | Balaji Rao, Todd A. Anderson, Greta J. Orris, Ken A. Rainwater, Srinath Rajagopalan, Renee M. Sandvig, Bridget R. Scanlon, David A. Stonestrom, Michelle Ann Walvoord, W Andrew Jackson |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Environmental Science & Technology |
Index ID | 70029966 |
Record Source | USGS Publications Warehouse |
USGS Organization | Nevada Water Science Center; Toxic Substances Hydrology Program |