Estrogen Transport in Surface Runoff from Agricultural Fields Treated with Two Application Methods of Dairy Manure

Culturable antibiotic-resistant fecal coliform bacteria in soil and surface runoff after liquid dairy manure surface application and subsurface injection

Land application of manure, while beneficial to soil health and plant growth, can lead to an overabundance of nutrients and introduction of emerging contaminants into agricultural fields. Compared with surface application of manure, subsurface injection has been shown to reduce nutrients and antibiotics in surface runoff. However, less is known about the influence of subsurface injection on the transport and persistence of antibiotic-resistant microorganisms. We simulated rainfall to field plots at two sites (one in Virginia and one in Pennsylvania) 1 or 7 d after liquid dairy manure surface and subsurface application (56 Mg ha^-1 ) and monitored the abundance of culturable antibiotic-resistant fecal coliform bacteria (ARFCB) in surface runoff and soils for 45 d. We performed these tests at both sites in spring 2018 and repeated the test at the Virginia site in fall 2019. Manure subsurface injection, compared with surface application, resulted in less ARFCB in surface runoff, and this reduction was greater at Day 1 after application compared with Day 7. The reductions of ARFCB in surface runoff because of manure subsurface injection were 2.5-593 times at the Virginia site in spring 2018 and fall 2019 and 4-5 times at the Pennsylvania site in spring 2018. The ARFCB were only detectable in the 0-to-5-cm soil depth within 14 d of manure surface application but remained detectable in the injection slits of manure subsurface-injected plots even at Day 45. This study demonstrated that subsurface injection can significantly reduce surface runoff of ARFCB from manure-applied fields.

Fate and transport in environmental quality

Changes in pollutant concentrations in environmental media occur both from pollutant transport in water or air and from local processes, such as adsorption, degradation, precipitation, straining, and so on. The terms "fate and transport" and "transport and fate" reflect the coupling of moving with the carrier media and biogeochemical processes describing local transformations or interactions. The Journal of Environmental Quality (JEQ) was one of the first to publish papers on fate and transport (F&T). This paper is a minireview written to commemorate the 50th anniversary of JEQ and show how the research interests, methodology, and public attention have been reflected in fate and transport publications in JEQ during the last 40 years. We report the statistics showing how the representation of different pollutant groups in papers changed with time. Major focus areas have included the effect of solution composition on F&T and concurrent F&T, the role of organic matter, and the relative role of different F&T pathways. The role of temporal and spatial heterogeneity has been studied at different scales. The value of long-term F&T studies and developments in modeling as the F&T research approach was amply demonstrated. Fate and transport studies have been an essential part of conservation measure evaluation and comparison and ecological risk assessment. For 50 years, JEQ has delivered new insights, methods, and applications related to F&T science. The importance of its service to society is recognized, and we look forward to new generations of F&T researchers presenting their contributions in JEQ.

The emergence, trajectory, and impacts of emerging contaminants publications in the Journal of Environmental Quality

As analytical capabilities in the early 2000s began to enable the detection of chemicals in environmental media at increasingly small concentrations, chemicals with the potential to cause adverse human and ecosystem health effects began to be found nearly ubiquitously worldwide. The types of chemicals that were targeted for analysis included natural and synthetic hormones, human and veterinary pharmaceuticals, chemicals in personal care products, novel pesticides, nanoparticles, microplastics, and other chemicals of natural and synthetic origin. The impacts of these chemicals on environmental and human health in many cases remain unknown. Collectively, these chemicals became known as "emerging contaminants" or "contaminants of emerging concern." Much progress has been made toward understanding the sources of these contaminants in the environment, the processes that control their fate and transport once they are released into the environment, and the ability of technology and/or best management practices to mitigate their occurrence. As the Journal of Environmental Quality (JEQ) celebrates its 50th anniversary, we sought to understand how publications in the journal have made impactful contributions in the research area of emerging contaminants. Here, we present the trajectory of publications in JEQ that have shaped knowledge in this field, highlight the importance of these contributions, and conclude with opportunities for JEQ to continue attracting high-quality emerging contaminants research.

Evidence that watershed nutrient management practices effectively reduce estrogens in environmental waters

We evaluate the impacts of different nutrient management strategies on the potential for co-managing estrogens and nutrients in environmental waters of the Potomac watershed of the Chesapeake Bay. These potential co-management approaches represent agricultural and urban runoff, wastewater treatment plant effluent, and combined sewer overflow replacements. Twelve estrogenic compounds and their metabolites were analysed by gas chromatography-mass spectrometry. Estrogenic activity (E₂Eq) was measured by in vitro bioassay. We detected estrone E₁ (0.05-6.97 ng L^-1) and estriol E₃ (below detection-8.13 ng L^-1) and one conjugated estrogen (estrone-3-sulfate E₁-3S; below detection-8.13 ng L^-1). E₁ was widely distributed and positively correlated with E₂Eq, water temperature, and dissolved organic carbon (DOC). Among nonpoint sources, E₂Eq, and concentrations of E₁, soluble reactive phosphorus (SRP) and total dissolved nitrogen (TDN) decreased by 51-61%, 77-82%, 62-64%, 4-16% in restored urban and agricultural streams with best management practices (BMPs) relative to unrestored streams without BMPs. In a wastewater treatment plant (Blue Plains WWTP), >94% of E₁, E₁-3S, E₃, E₂Eq and TDN were removed while SRP increased by 305% during nitrification/denitrification as a part of advanced wastewater treatment. Consequently, E₁ and TDN concentrations in WWTP effluents were comparable or even lower than those observed in the receiving stream or river waters, and the effects of wastewater discharges on downstream E₁ and TDN concentrations were minor. Highest E₂Eq value and concentrations of E1, E3, and TDN were detected in combined sewer overflow (CSO). This study suggests that WWTP upgrades with biological nutrient removal, CSO management, and certain agricultural and urban BMPs for nutrient controls have the potential to remove estrogens from point and nonpoint sources along with other contaminants in streams and rivers.

Assessing surface and subsurface transport of neonicotinoid insecticides from no-till crop fields

Increased use of neonicotinoid-coated crop seeds introduces greater amounts of insecticides into the environment, where they are vulnerable to transport. To understand the transport of neonicotinoids from agricultural fields, we planted maize (Zea mays L.) seeds coated with thiamethoxam in lysimeter plots in central Pennsylvania. Over the next year, we sampled water generated by rainfall and snowmelt and analyzed these samples with mass spectrometry for the neonicotinoids thiamethoxam and clothianidin (metabolite), which originated from the coated seeds. For surface and subsurface transport, thiamethoxam exhibited "first-flush" dynamics, with concentrations highest during the first events following planting and generally decreasing for the remainder of the study. The metabolite clothianidin, however, persisted throughout the study. The mass of thiamethoxam and clothianidin exported during the study period accounted for 1.09% of the mass applied, with more than 90% of the mass transported in subsurface flow and less than 10% in surface runoff. These results suggest that surface runoff, at least for our site, is a relatively small contributor to the overall fate and transport of these insecticides and that the delivery ratio (i.e., mass exported/mass applied) observed for these compounds is similar to those of other trace-level emerging contaminants known to negatively influence aquatic ecosystems.

Spatio-temporal distribution and transformation of 17α- and 17β-estradiol in sterilized soil: A column experiment

The environmental behaviors of steroid estrogens (SEs) associated with land irrigation and application are of critical concern worldwide. Understanding the spatio-temporal distribution and transformation process of these estrogenic compounds in soil is greatly significant. In this study, laboratory soil column experiments were conducted to investigate and explore the migration and abiotic transformation of 17α-estradiol (17α-E2) and 17β-estradiol (17β-E2) over spatial and time scales. Results indicated that the migration tendency of 17α-E2 and 17β-E2 was similar. Discrepancies in transport for different SEs groups might be due to the competitive sorption and isomeric transformation in the binary-solute system. 17α-E2 and 17β-E2 can also undergo the abiotic transformation during soil column transport. The soil with naturally abundant mineral substances (e.g., iron and manganese oxides) indicated that E2 isomers tended to mineral-promoted racemization, oxidation, reduction, and radical coupling reactions. Some possible transformation products (e.g., SE₂₃₉, E2₃₇₈, and SE dimer₄₇₆) were identified and proposed in soil samples. Compared to the single compound tests, the estimated 17β-estradiol equivalency (EEQ) values of E2 mixture were higher during SEs migration process.

Fate of pharmaceuticals in a spray-irrigation system: From wastewater to groundwater

Land application of wastewater effluent is beneficial for recharging groundwater aquifers and avoiding direct pollutant discharges to surface waters. However, the fate of non-regulated organic wastewater pollutants, such as pharmaceuticals and personal care products (PPCPs), in such wastewater reuse systems is understudied. Here, a 14-month study (October 2016 through December 2017) was conducted to evaluate the fate and potential risks of seven commonly used PPCPs in a local wastewater treatment plant (WWTP) and from 13 groundwater monitoring wells at a spray-irrigation site where effluent has been spray-irrigated since the early 1980s. Acetaminophen and trimethoprim were the most frequently detected (93%) PPCPs in WWTP influent, while in the effluent, caffeine and trimethoprim were detected most frequently (70%). Wastewater treatment generally reduced concentrations of acetaminophen and caffeine by >88%; however, some compounds had low removal or were present at higher concentrations in the effluent compared with influent (e.g. naproxen, sulfamethoxazole, trimethoprim and ofloxacin). Seasonal trends were observed, with higher PPCP concentrations in the WWTP influent and effluent in the winter. Risk calculations conducted on the wastewater effluent suggest that the risk posed by PPCPs that persisted in the effluent are medium to high to aquatic organisms. Detection frequencies of PPCPs were lower in groundwater samples compared to the effluent, with sulfamethoxazole (40%) and caffeine (32%) as the most frequently detected compounds. Similarly, average concentrations of PPCPs in groundwater were found to be nearly two orders of magnitude lower than concentrations in the effluent. Minimal seasonal influence was observed for groundwater samples. Human health risk assessments indicate that concentrations in groundwater, which is used as a drinking water source, appear to pose minimal risk.

In Vitro and In Vivo Assessment of Aqueously Extractable Estrogens in Poultry Manure after Pilot-scale Composting

Poultry manure contains free and conjugated forms of the natural estrogens 17β-estradiol and estrone, which can be transported to receiving waters via runoff when land-applied. Previous studies have demonstrated estrogens in runoff from poultry manure-amended fields but have not tracked changes in estrogenicity within this water over time. Microbial conversion of conjugated estrogens (a major portion of water-extractable estrogens) to parent forms may result in temporary increases in estrogenicity in natural water bodies. The present study created 80-L batches of simulated poultry manure runoff, which were investigated over 10 d for estrogenicity by bioluminescent yeast estrogen screen assay and fathead minnow () vitellogenin induction model. The efficacy of different compost conditions (in-vessel aeration ± turning, and piling) on reduction/elimination of aqueously extractable estrogens in poultry manure was also investigated. Results indicate 3- to 10-fold increases in estrogenicity in various poultry manure mixtures during 10-d observations. Estrogenicity returned to low levels in postcompost treatments but remained elevated in the precompost treatment. Aerated compost resulted in >75% reductions in initial, peak, and 10-d mean estrogenicity in aqueous mixtures (0.3, 0.8, and 0.5 ng 17β-estradiol equivalents [EEQ] L, respectively) compared with the precompost mixture (1.4, 4.8, and 2.1 ng EEQ L, respectively). Estrogenicity was significantly higher in the aqueous extract from the piled treatment than the aerated treatment, and 10-d exposure of male fish to the piled treatment resulted in statistically significant vitellogenin induction. Collectively, our results suggest a need to investigate estrogenicity in surface waters for several days after receiving manure-influenced runoff.