The Fate, Transformation and Persistence of Natural and Synthetic Estrogens in Surface Waters Impacted by Dairy Manure Application and Effluent Irrigation

Open Access
- Author:
- Mina, Odette
- Graduate Program:
- Agricultural and Biological Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 24, 2016
- Committee Members:
- Heather E. Gall, Dissertation Advisor/Co-Advisor
Heather E. Gall, Committee Chair/Co-Chair
Herschel A. Elliott, Committee Member
John E. Watson, Committee Member
Richard C. Ciocci, Outside Member - Keywords:
- fate
transport
estrogens
degradation
anaerobic
surface runoff
vernal pool
effluent irrigation
dairy manure application
concentration-discharge and load-discharge relationships
comparison of phosphorus and dissolved organic carbon and estrogens exported loads in surface runoff from agricultural fields - Abstract:
- The presence of emerging contaminants (ECs) in the environment has become a great concern in recent years. Many ECs are known to be endocrine disrupting compounds (EDCs) and they include natural estrogens and synthetic estrogens, which have been detected in surface waters worldwide. Effluent discharged to downstream water bodies from wastewater treatment plants, and surface runoff from manure-amended fields, are two important pathways of estrogens into the environment. In order to manage these wastes in a sustainable manner, more research is needed to understand the impacts of land application activities on water quality and contaminant fate and transport. While the land application of animal manure provides many benefits, concerns exist regarding the subsequent transport of estrogens and the potential impacts on aquatic ecosystems. The effects of two methods of dairy manure application, surface broadcast and shallow disk injection, on the fate and transport of natural estrogens in surface runoff were examined. Ten natural surface runoff events were sampled over a 9-mo. period following fall manure application, in October of 2014, to 12 large field plots in Central Pennsylvania, USA. Study results show that the range of estrogen concentrations observed in surface runoff from the broadcast plots was several orders of magnitude higher ( > 5000 ng L-1) than the concentrations in runoff from the shallow disk injection plots ( < 10 ng L-1). Additionally, the transport dynamics differed, with the majority of the estrogen loads from the surface broadcast plots occurring during the first rainfall event after application, whereas the majority of the loads from the shallow disk injection plots occurred more than six months later during a hail storm event. Total estrogen loads were, on average, two orders of magnitude lower for shallow disk injection compared to surface broadcast. Independent of the method of manure application, 17-estradiol and its metabolite estrone were preserved in the field for as long as nine months following application. Overall, injection of manure shows promise in reducing the potential for off-site losses of estrogens from manure-amended soils. The effects of surface broadcast and shallow disk injection on nutrient export dynamics were also investigated and compared to estrogen dynamics. Various methods of data analysis were employed to investigate the role played by hydrologic and biogeochemical variability on the export of estrogens, identifying similarities and differences to the export of total dissolved phosphorus (TDP) and dissolved organic carbon (DOC). Our data analysis revealed that hydrologic variability was the dominant driver of TDP and DOC transport for both application types, whereas for estrogen transport concentration variability played a more important role with a more pronounced effect for the surface broadcast relative to the shallow disk injection application. More than 90% of the exported loads were transported during the first event for the surface broadcast plots, whereas the shallow disk injection plots did not generate runoff during that event, and nearly 65% of the estrogen loads were transported during a hail event at the end of April 2015, more than six months after manure applications. The presence of natural and synthetic estrogens in treated wastewater used for irrigation of agricultural fields poses a potential risk to surface water ecosystems. While several recent studies have investigated the occurrence, fate, and transport of estrogens in the environment, the vast majority of these studies have focused on the fate of estrogens in streams and rivers. However, no studies have been conducted to assess the occurrence, persistence, and fate of estrogens in impacted sensitive aquatic ecosystems such as vernal pools. This is of particular importance because vernal pools serve as critical breeding habitat for amphibians, which are known to be sensitive to the presence of endocrine disrupting compounds. A spray irrigation system was implemented over 50 years ago at The Pennsylvania State University’s (Penn State) “Living Filter” as an alternative to discharging treated wastewater to a high quality trout stream. This system introduces all of Penn State’s treated wastewater onto approximately 250 hectares of agricultural and forested land at a rate of ~ 5 cm ha-1 week-1. More than a dozen small, temporary surface bodies (pools) are impacted by this wastewater irrigation, with some pools adjacent to irrigation laterals receiving direct inputs of the treated wastewater. The goal of this study was to assess the impact of these weekly irrigation activities on the transformation, persistence, and fate of estrogens (17α-estradiol, 17β-estradiol, estrone, estriol, and 17α-ethinylestradiol) in three vernal pools (VPs) during an eight-week field study. The spring 2015 study period coincided with wood frog breeding and metamorphosis. Irrigation wastewater was collected weekly and water samples near the sediment-water interface in each VP were collected daily. Real-time monitoring stations continuously recorded the temperature, pH, oxidation-reduction (ORP) potential, dissolved oxygen (DO), electrical conductivity (EC), and water level at each VP. Nearly 100% of the VP daily samples (n = 137) collected contained estrogens, and the concentrations were several times higher compared to the wastewater irrigation water. Estrone was the most frequently detected estrogen and 17α-estradiol was detected in almost 52% of the daily samples. Additionally, the data suggest transformation of estrone back to 17α-estradiol due to reduced oxygen/anaerobic conditions in the VPs. This unique field study suggests that more research is needed to quantify the potential impact of estrogenic activity on amphibians, particularly during their critical metamorphosis period. The work completed for this dissertation improves the current knowledge of the fate and transport of natural and synthetic estrogens under environmentally relevant conditions. The studies improved the current understanding of the transformation, persistence, and overall fate of natural and synthetic estrogens in surface runoff from agricultural fields treated with dairy manure, and in alternating aerobic, reduced oxygen, and anaerobic conditions of VP habitats.