Skip to main content
ARS Home » Research » Publications at this Location » Publication #324204
Title: Parent and conjugated estrogens and progestagens in surface water of the Santa Ana River: Determination, occurrence, and risk assessment

Author
item MA, LI - University Of California
item Yates, Scott
item ASHWORTH, DANIEL - University Of California

Submitted to: Environmental Toxicology and Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2016
Publication Date: 4/6/2016
Citation: Ma, L., Yates, S.R., Ashworth, D. 2016. Parent and conjugated estrogens and progestagens in surface water of the Santa Ana River: Determination, occurrence, and risk assessment. Environmental Toxicology and Chemistry. 35(11):2657-2664. doi: 10.1002/etc.3447.

Interpretive Summary: Concern has been raised over steroid hormones in recent years due to their endocrine disrupting effects on aquatic organisms. The adverse effects include intersexuality, masculinization, and reproductive and behavioral problems. Steroidal hormones are naturally produced in mammalian bodies or synthesized by drug companies and are used to treat humans and livestock. A significant portion of the hormones is excreted via urine and feces, mainly in the form of biologically inactive conjugates and partially as the active precursors or metabolites, causing the potential for environmental contamination. The Santa Ana River plays a paramount role in supporting the local biodiversity and freshwater supply in a large urban area of Southern California. The flow of the river begins in the San Bernardino Mountains and extends to the Prado Basin and Santa Ana Canyon, passing through an urban area with a large concentration of cattle operations. Concerns arises from the contamination of this river by estrogenic disrupting compounds (hormones, etc.) released from both urban and agricultural runoff. However, it is not known whether the hormones occur at concentrations sufficient to pose a threat to the aquatic organisms in the river. It is also unclear whether the major sources are municipal wastewater or animal feeding operations. To address this, a liquid chromatography-mass spectrometry (LC/MS) method was developed to investigate the spatial occurrence of selected hormones and their conjugates, to determine the contribution of major sources to the total hormone burden, and assess the potential risks posed to aquatic organisms. Such results are essential for pollution control and risk assessment in the river and its surrounding area. This information is important in developing strategies for protecting valuable water ways and would be of interest to researchers, regulators, water supply utilities, and the public.

Technical Abstract: This study presents a sensitive analytical method using high performance liquid chromatography tandem mass spectrometry for the simultaneous monitoring of five estrogen conjugates, six estrogens and two progestagens in surface water of the Santa Ana River. Samples at ten representative sites along the Santa Ana River and its major estuary were investigated to provide a snapshot of the occurrence and spatial distribution of steroid hormones and estrogen conjugates. With the exception of the synthetic hormones 17 alpha-ethynylestradiol and mestranol, other compounds were detected at least twice, with the ubiquitous estrone (E1) and 17beta-estradiol-3-sulfate (E2-3S) as the dominant compounds quantified (0.24–6.37 ng/L and 0.49–9.25 ng/L, respectively). Sites near dairy farms exhibited high levels of conjugates while those close to a sewage treatment plant (STP) effluent outlet displayed relatively high concentrations of E1. Principle component analysis coupled with multiple linear regression revealed dairy farms and the STP as the two significant contamination sources, accounting for 69.9 and 31.1% of the total hormone burden, respectively. Risk assessment results suggested E1 and 17beta-estradiol (E2) as the two hormones with the largest risk to aquatic organisms, and which combined, contributed >90% of the total estrogenicity. Most of the sites investigated showed that E1 and E2 posed a medium risk (0.1 < risk quotient <1), while each induced high risk (risk quotient > 1) at sites impacted by the STP and dairy farms. These results suggest that river health would benefit from effective treatment of waste produced by the STP and dairy farms prior to discharge.