Selenium Hazards in the Salton Sea Environment— Summary of Current Knowledge to Inform Future Wetland Management

U.S. Geological Survey (USGS) | July 20th, 2023

Quaternary marine and continental shales in the western United States are sources of selenium that can be loaded into the aquatic environment through mining, agricultural

Quaternary marine and continental shales in the western United States are sources of selenium that can be loaded into the aquatic environment through mining, agricultural, and energy production processes. The mobilization of selenium from shales through agricultural irrigation has been recognized since the 1930s; however, discovery of deformities in birds and other wildlife using agricultural habitats during the 1980s spurred studies to determine the extent and effects of the contamination. Through these early studies, researchers determined that biota in the Salton Sea drainage basin was at risk from legacy selenium contamination in the Colorado River watershed.

Selenium in White Sturgeon from North San Francisco Bay: The 2015-2017 Sturgeon Derby Study

San Francisco Estuary Institute (SFEI) | October 1st, 2019

This report presents the findings from a study evaluating selenium concentrations in white sturgeon (Acipenser transmontanus) tissues collected during the 2015-2017 Sturg

This report presents the findings from a study evaluating selenium concentrations in white sturgeon (Acipenser transmontanus) tissues collected during the 2015-2017 Sturgeon Derby events in North San Francisco Bay. The goal of this study was to investigate the distribution of selenium among sturgeon tissues to inform the toxicological and regulatory interpretation of selenium measured in non-lethally collected tissues, including muscle plugs and fin rays. This technical report provides documentation of the study and presents its major findings. 

Shrinking lakes, air pollution, and human health: Evidence from California's Salton Sea

Science of the Total Environment (Elsevier) | January 7th, 2020

Due to increased water withdrawals and ongoing climate change, many inland lakes around the world are shrinking and dry lake beds can be significant sources of particulat

Due to increased water withdrawals and ongoing climate change, many inland lakes around the world are shrinking and dry lake beds can be significant sources of particulate matter air pollution. Using a natural experiment provided by the shrinking Salton Sea in California, this paper shows that each one-foot drop in lake elevation is associated with a 0.28 μg/m3 (2.6%) increase in PM2.5 concentrations. IV model results then show that Salton Sea-induced changes in PM2.5 over 1998–2014 led to increases in respiratory mortality of 1.4/yr.–15.6/yr. in the counties surrounding the lake, generating $13.2–$147.3 million in annual health costs.

Sources of high-chloride water and managed aquifer recharge in an alluvial aquifer in California, USA

Hydrogeology Journal (Springer) | July 3rd, 2015

Temporal variability in irrigated land and climate influences on salinity loading across the Upper Colorado River Basin, 1986-2017

Environmental Research Letters (IOP) | January 19th, 2024

The disappearing Salton Sea: A critical reflection on the emerging environmental threat of disappearing saline lakes and potential impacts on children's health

Science of the Total Environment (Elsevier) | February 6th, 2019

Changing weather patterns, droughts and competing water demands are dramatically altering the landscape and creating conditions conducive to the production of wind-blown

Changing weather patterns, droughts and competing water demands are dramatically altering the landscape and creating conditions conducive to the production of wind-blown dust and dust storms. In California, such factors are leading to the rapid shrinking of the Salton Sea, a 345 mile2 land-locked “sea” situated near the southeastern rural border region known as the Imperial Valley. The region is anticipated to experience a dramatic increase in wind-blown dust and existing studies suggest a significant impact on the health and quality of life for nearby residents of this predominantly low-income, Mexican-American community. The discussion calls attention to the public health dimensions of the Salton Sea crisis. We know little about the possible long-term health effects of exposure to mobilized lakebed sediments or the numerous toxic contaminants that may become respirable on entrained particles. We draw on existing epidemiological literature of other known sources of wind-blown dust, such as desert dust storms, and related health effects to begin to understand the potential public health impact of wind-blown dust exposure. The increased production of wind-blown dust and environmental exposures to such non-combustion related sources of particulate matter are a growing health threat, due in part to drought coupled with increasing pressures on limited water resources. Recent population-based studies have linked dust storms with cardiovascular mortality, asthma hospitalization and decrease in pulmonary function in both adults and children. A growing number of studies provide evidence of the acute health effects of wind-blown dust exposures among children, which with repeated insults have the potential to influence respiratory health over time. The shrinking of the Salton Sea illustrates a public health and environmental justice crisis that requires action and attention to protect the health and well-being of local communities.

The Effect of a Receding Saline Lake (The Salton Sea) on Airborne Particulate Matter Composition

American Chemical Society (ACS) | July 12th, 2017

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 influenc

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.

Water quality for agriculture

Food and Agriculture Organization of the United Nations (FAO) | July 15th, 1985

Watershed-scale Evaluation of Agricultural BMP Effectiveness in Protecting Critical Coastal Habitats: Final Report on the Status of Three Central California Estuaries

Central Coast Regional Water Quality Control Board (CCRWQCB) | April 30th, 2010

Along California's Central Coast, the Pajaro, Salinas, and Santa Maria Rivers drain to coastal estuaries that provide essential habitat for early life stages of commercia

Along California's Central Coast, the Pajaro, Salinas, and Santa Maria Rivers drain to coastal estuaries that provide essential habitat for early life stages of commercially and recreationally important marine fish species, threatened anadromous fish species, migratory birds, and other wildlife. These are the largest watersheds on the central coast and each contains year-round, intensively cultivated agricultural land that supports a $3.5 billion/year industry producing most of the nation's lettuce, artichokes, and crucifer crops. Runoff from irrigated agriculture constitutes a significant portion of river flow during most of the year, and a number of studies have documented pesticide occurrence and biological impacts in these watersheds. Evidence of pesticide impacts has encouraged diverse stakeholders to begin implementing farm management practices (MPs) to reduce pesticide concentrations and toxicity in agricultural runoff. This project is designed to complement ongoing evaluations of individual MPs with measurements of pesticide concentrations throughout the estuarine environments, including the water column, sediments, and in resident biota. Biological effects were measured at the organism and community levels. Chemical analyses emphasized pesticide impacts because previous research in these watersheds has indicated these are the primary chemicals of concern impacting beneficial uses. A broad suite of pesticides were measured, including legacy organochlorines, widely-used organophosphates, increasingly-used pyrethroids, herbicides and fungicides. Sampling in the three estuaries was conducted from January 2008 until October 2009. A total of fifteen sampling events were conducted in each estuary, and these were divided between eleven irrigation season events and four storm events. Storm and irrigation monitoring included water toxicity and chemistry analyses for pesticides. Samples were collected at multiple stations in the estuaries and in key tributaries flowing to the estuaries. In addition, sediment toxicity was assessed at eight estuary stations and the tributary stations during three irrigation season sampling events. Benthic community characterizations were also conducted in May and October 2008. All sediment samples were analyzed for pesticides, as well as grain size and total organic carbon. Pesticide analyses in resident fish and sand crab tissues were conducted once in each estuary. The goal of this project was to establish a baseline of estuary conditions with respect to pesticide impacts as MPs are beginning to be implemented.

Willingness to Pay to Protect Wetlands and Reduce Wildlife Contamination from Agricultural Drainage

Springer | December 2nd, 1991

This chapter presents the results of a survey of the general population in California regarding their willingness to pay for alternative programs to protect and expand we

This chapter presents the results of a survey of the general population in California regarding their willingness to pay for alternative programs to protect and expand wetlands as well as reduce wildlife contamination in the San Joaquin Valley (Valley). The results of 803 completed interviews from 1,573 successfully contacted households indicate that Californians would pay $154 each year in higher taxes to purchase water to prevent a decrease in wetland acreage from 85,000 acres to 27,000 acres. This value rose to $254 to provide foran increase in wetland acreage to 125,000 acres with an associated 40 percent increase of bird populations. California households would pay $313 each year in additional taxes to implement agricultural drainage programs that would reduce waterbirds exposure to contamination from 70 percent to 20 percent exposure. The water management implication of these results is that Californians value clean water supplies for refuges at over $3 billion a year.