The effect of particle size on sorption of estrogens, androgens and progestagens in aquatic sediment

Transport of prednisolone, cortisone, and triamcinolone acetonide in agricultural soils: Sorption isotherms, transport dynamics, and field-scale simulation

The occurrence of glucocorticoids (GCs) in agricultural soils has raised concerns due to their high polarity, widespread biological effects in vertebrates, and their potential to disrupt vital processes such as glucose metabolism and immune function. This study investigated the sorption and transport dynamics of three GCs, namely cortisone (COR), prednisolone (PNL), and triamcinolone acetonide (TCA) in five soil-water systems (S1-S5 systems). The sorption data of the GCs were fitted to a linear sorption model (R2 = 0.95-0.99), with organic carbon (OC) normalized sorption coefficients ranging from 2.26 ± 0.02 to 3.36 ± 0.02. The sorption magnitudes (Kd) of the GCs exhibited a nearly linear correlation with their corresponding octanol-water partition coefficients (logKow) in the S1-S3 systems. However, some deviations from linearity were observed in the S4 and S5 systems. Furthermore, a strong correlation was observed between the Kd values of the GCs and the OC% of the soils. These data indicated that specific and hydrophobic partitioning interactions governed the sorption of GCs onto soils. The transport data of the GCs were fitted to a two-site nonequilibrium model using the CXTFIT program (R2 = 0.82-0.98). The retardation factor (R) for each GC exhibited a positive correlation with the OC% and clay contents of soils. Additionally, the relationships between the logR values and logKow values of the GCs deviated slightly from linear correlation in most columns. These results indicated that specific interactions in the columns were more pronounced compared to the batch systems. An initial field-scale simulation demonstrated that frequent precipitation can facilitate the dilution and vertical transport of the GCs through soil profiles. The transport potential of the GCs was affected by the properties and soils and GCs. Overall, these findings provide valuable insights into the transport potential and associated environmental risks of GCs in soil-water systems.

An effective tool for tracking steroids and their metabolites at the watershed level: Combining fugacity modeling and a chemical indicator

Steroids have attracted concern worldwide because of their potential carcinogenicity and severe adverse effects on aquatic organisms. However, the contamination status of various steroids, particularly their metabolites, at the watershed level remains unknown. This was the first study to employ field investigations to elucidate the spatiotemporal patterns, riverine fluxes, and mass inventories, and conduct a risk assessment of 22 steroids and their metabolites. This study also developed an effective tool for predicting the target steroids and their metabolites in a typical watershed based on the fugacity model combined with a chemical indicator. Thirteen steroids in the river water and seven steroids in sediments were identified with total concentrations of 1.0-76 ng/L and <LOQ-121 ng/g, respectively. In water, the levels of steroids were higher in the dry season, but the opposite trend was observed in sediments. Approximately 89 kg/a flux of steroids were transported from the river to the estuary. Mass inventories indicated that sediments acted as crucial sinks for steroids. Steroids in rivers might pose low to medium risks to aquatic organisms. Importantly, the fugacity model combined with a chemical indicator effectively simulated the steroid monitoring results within an order of magnitude at the watershed level, and various key sensitivity parameter settings provided reliable steroid concentration predictions under different circumstances. Our results should benefit environmental management and pollution control of steroids and their metabolites at the watershed level.

Free and conjugated forms of metabolites are indispensable components of steroids: The first evidence from an estuarine food web

Steroids have attracted particular attention as environmental contaminants because of their severe endocrine-disrupting effects. Previous studies have predominantly focused on parent steroids; however, the levels and proportions of the free and conjugated forms of their metabolites remain largely unclear, especially in food webs. Here, we first characterized the free and conjugated forms of parent steroids and their metabolites in 26 species in an estuarine food web. The steroids were dominated by their metabolites in water samples, whereas parent compounds were predominant in sediment samples. The total mean steroid concentrations in the biota samples that underwent non-enzymatic hydrolysis decreased in the following order: crabs (27 ng/g) > fish (5.9 ng/g) > snails (3.4 ng/g) > shrimps and sea cucumbers (1.2 ng/g); and those in the biota samples that underwent enzymatic hydrolysis decreased in the following order: crabs (57 ng/g) > snails (9.2 ng/g) > fish (7.9 ng/g) > shrimps and sea cucumbers (3.5 ng/g). The proportion of metabolites in the enzymatic hydrolysis biota samples was higher (38-79%) than that (2.9-65%) in non-enzymatic ones, indicating that the free and conjugated forms of metabolites in aquatic organisms were not negligible. Most synthetic steroids were either bioaccumulative or highly bioaccumulative. Importantly, in the invertebrate food web, 17α-methyltestosterone was biomagnified, while 17β-boldenone underwent trophic dilution. Although the estuarine water had a median ecological risk level, the health risks via aquatic product consumption were very low. This study provides novel insights into the composition and trophic transfer of steroids in an estuarine food web for the first time and highlights that free and conjugated metabolites should receive more attention, particularly in biota samples.

Sorption and desorption of epiandrosterone and cortisol on sewage sludge: Comparison to aquatic sediment

Steroids have aroused global concern due to their potent endocrine-disrupting effects. Androgens and glucocorticoids are the most abundant species in sewage; however, our understanding of their fate and risks from the source to environmental sinks remains elusive. This study compared the sorption-desorption characteristics of epiandrosterone (EADR) and cortisol (CRL) in sewage sludge and aquatic sediment, and the surface and molecular interactions were tentatively investigated through infrared spectroscopy and the fluorescence excitation-emission matrix. The results showed that the sorption capacities of EADR and CRL in the sludge were 4015 L/kg and 81.17 L/kg, respectively, which are much larger than those in the sediment (EADR: 78.77 L/kg, CRL: 6.39 L/kg); 0.02%-1.2% of EADR and 0.2%-14.5% of CRL could be desorbed from sludge, while the desorption ratios were even lower in the sediment. The high organic content in the sludge might contribute to the larger sorption capacities, while the weak interaction between steroids and organic matter could lead to larger desorption potential. The sediment contained more mineral content and featured a larger specific surface area, which could be responsible for the greater desorption hysteresis for EADR and CRL. These results will help to better understand the potential risk of sewage sludge-associated steroids and their distribution in sediment-water systems.

Insight into different adsorption behaviors of two fluoroquinolone antibiotics by sediment aggregation fractions

Sediment, consisting of different aggregation fractions, is a hotspot site for transport and transformation of various pollutants including antibiotics. However, the fate of different antibiotics in aquatic sediments mediated by sediment aggregation fraction adsorption and the mechanism behinds are still unclear. In this study, we investigated the adsorption behavior of two fluoroquinolone antibiotics (ciprofloxacin and ofloxacin) on four aggregation fractions separated from the sediment of Taihu Lake, a typical lake contaminated by antibiotics in China. The results showed that the adsorption of ciprofloxacin and ofloxacin fitted the Freundlich model, irrespective of sediment aggregation size. The adsorption of ciprofloxacin and ofloxacin was depended on the size of sediment aggregation fractions, and the macroaggregation (> 200 μm) exhibited the strongest capacity, followed by large microaggregation (63-200 μm), medium microaggregation (20-63 μm), and small and primary microaggregation (< 20 μm). This fraction size-dependent effects of sediment aggregations on antibiotic adsorption might be closely related to the differences in their specific surface areas, organic matter contents, and surface functional groups. The adsorption of ciprofloxacin and ofloxacin by sediment aggregation fractions was characterized by a combination of chemical and physical adsorptions, with the former being the dominant process. Compared with ofloxacin, ciprofloxacin could be more rapidly and easily absorbed by four sediment aggregation fractions, and more readily complexed with carboxyl groups on macroaggregation surface. The adsorption of two antibiotics by extracellular polymeric substance showed that tryptophan and tyrosine protein-like, humic-like substance on the surface of sediment could bind to both antibiotics through a complexation reaction. The π-π electron donor-acceptor interaction and hydrogen bonds were responsible for the antibiotic adsorption by sediment aggregation.

The response of steroid estrogens bioavailability to various sorption mechanisms by soil organic matter extracted with sequential alkaline-extraction method from an agriculture soil

The long-term groundwater contamination risks posed by steroidal estrogens (SEs) in animal-manured agricultural soils are closely associated with the soil organic matter (SOM) content and composition. In this study, the bioavailability of estrone (E1) and 17β-estradiol (17β-E2) under different sorption mechanism in humic acids (HA1 and HA2) and humin (HM) extracted with sequential alkaline-extraction technique (SAET) were examined. These SOMs extracted by SAET showed various properties and sorption characteristics for SEs. The alkyl carbon and condensed SOM increased during SAET, but aromatic carbon decreased and the same trend for polarity. Quick sorption was the major SEs sorption mechanism on HA1 and HA2, which contributed more than 69%; whilst slow sorption rate was about 50% in soil and HM. The logK_oc values were proportional to the TOC of SOM according to Freundlich fitting, and the sorption capacity of sorbent for E1 and 17β-E2 was related to the logK_ow values, indicating that the main mechanism controlling the SEs sorption was hydrophobic interaction. The larger micropore volume of HM and soil was more conducive to the micropore filling of SEs. Meanwhile, the specific sorption of SEs on condensed domain of SOM was the main reason for the strong desorption hysteresis and slow sorption in HM and soil. The SEs degradation rate was positively correlated with the contribution rate of quick adsorption and negatively correlated with the contribution rate of slow adsorption, indicating that the bioavailability of SEs sorbed by hydrophobic interaction was higher than that of micropore filling or specific sorption, which was also the reason for the low bioavailability of SEs in HM and soil. This work confirms the regulation of on-site SOM compositions and their properties on SEs sorption and bioavailability. Characterization of these details is crucial for the improved prediction of long-term risks to groundwater.

Coupled steroid and phosphorus leaching from cattle slurry at lysimeter scale

Water quality degradation can be caused by excessive agricultural nutrient transfers from fertilised soils exposed to wet weather. Mitigation measures within the EU Nitrates Directive aim to reduce this pressure by including 'closed' fertiliser spreading periods during wet months. For organic fertilisers such as slurry and manure, this closed period requires sufficient on-farm winter storage and good weather conditions to relieve storage at the end of the period. Therefore, robust scientific evidence is needed to support the measure. Incidental nutrient transfers of recently applied organic fertilisers in wet weather can also be complicated by synchronous transfers from residual soil stores and tracing is required for risk assessments. The combination of nutrient monitoring and biomarker analyses may aid this and one such biomarker suite is faecal steroids. Accordingly, this study investigated the persistence of steroids and their association with phosphorus during leaching episodes. The focus was on the coupled behaviour of steroids and total phosphorus (TP) concentrations in sub-surface hydrological pathways. Cattle slurry was applied to monolith lysimeters either side of a closed period and concentrations of both steroids and TP were monitored in the leachate. The study showed no significant effect of the treatment (average p = 0.17), though tracer concentrations did significantly change over time (average p = 0.001). While the steroidal concentration ratio was validated for herbivorous faecal pollution in the leachate, there was a weak positive correlation between the steroids and TP. Further investigation at more natural scales (hillslope/catchment) is required to confirm tracer behaviours/correlations and to compliment this sub-surface pathway study.

Contamination and ecological risks of steroid metabolites require more attention in the environment: Evidence from the fishing ports

Due to strong endocrine disrupting effects, steroids in the environment have attracted substantial attention, with studies mostly focusing on the parent steroids. Here, we conducted the first investigation on the contamination profiles, possible sources, mass inventories, and ecological risks of 27 steroids and their metabolites in 15 typical fishing ports in Southeast China. Twelve steroids were detectable in the sediment samples with the total mean concentrations of 4.6-35 ng/g. High proportions of steroid metabolites were measured in the sediments and five metabolites were newly observed. Untreated municipal sewage and aquaculture wastes constitute the possible steroid sources in the studied fishing ports. The total inventories of steroids in fishing ports ranged from 2.1-16 mg/m², with their metabolites being important contributors. The ecological risk analysis indicated high risks across all sampling sites mainly due to the contributions of parent steroids. Furthermore, our results found that progesterone is an acceptable chemical indicator for various steroids in sediments. This study provides the first evidence of steroid metabolites in the marine environment, calling for more studies in environmental behavior and ecotoxicology of steroid metabolites.

Extensive rain events have a more substantial impact than advanced effluent treatment on the endocrine-disrupting activity in an effluent-dominated small river

Wastewater treatment plants (WWTPs) remain an important primary source of emission for endocrine-disrupting compounds in the environment. As an advanced wastewater treatment process, ozonation is known to reduce endocrine-disrupting activity. However, it remains unclear to which extend improved wastewater treatment may reduce the endocrine-disrupting activity in the receiving water body. The present study investigated possible factors for the endocrine-disrupting activity in a small receiving water body, the Wurm River (North-Rhine Westphalia, Germany), up- and downstream of a local WWTP. The cell-based reporter gene CALUX® assay was applied to identify the endocrine-disrupting activity in the water, sediment, and suspended particulate matter. The water phase and the effluent sampling were primarily driven by applying the full-scale effluent ozonation (sampling campaigns in June 2017 and March 2019). In contrast, the sediment sampling aimed to compare the particle-bound endocrine-disrupting activity during dry (June 2017) and rainy summer (June 2018) seasons. The water phase showed low to moderate estrogenic/antiandrogenic activity. Advanced effluent treatment by ozonation led to a complete reduction of the endocrine-disrupting activity according to the limit of detection of the CALUX® assays. The suspended particulate matter originated from the water phase of the second sampling campaign revealed antiandrogenic activity only. Sediments at the sampling sites along the local WWTP revealed higher estrogenic and antiandrogenic activity after extensive rain events and were not affected by the ozonated effluent. Fluctuation patterns of the endocrine-disrupting activity in sediments were in line with fluctuated concentrations of polycyclic aromatic hydrocarbons. Rainwater overflow basin release was suggested as a vector for particle-bound and dissolved endocrine-disrupting activity in the receiving water body. The present study underlined the necessity for monitoring both water and sediment phases to achieve reliable profiling of the endocrine-disrupting activity. The receptor-mediated CALUX® assays were proven to be suitable for investigating the endocrine-disrupting activity distribution in different river compartments and WWTP effluents.

Monitoring estrogen and androgen residues from livestock farms in Phayao Lake, Thailand

The aim of the present study was to investigate steroid hormone residues from livestock farms and assess their risks to the surface water of Phayao Lake. These steroid hormones are endocrine-disrupting compounds (EDCs), which can be found in natural and synthetic forms. This research focused on examining the residues of seven steroid hormones (five estrogens and two androgens-estrone (E1), 17α-estradiol (αE2), 17β-estradiol (βE2), estriol (E3), 17α-ethinyl estradiol (EE2), testosterone (T), and 17α-methyltestosterone (MT)) from four types of livestock farms around Phayao Lake, Thailand. The samples collected from the livestock farms included feces, soil, and wastewater and were extracted by the solid phase extraction (SPE) technique and analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). The risks from the residual steroid hormones were also characterized by estradiol equivalents (EEQs), testosterone equivalents (TEQs), and risk quotients (RQs). The results indicated that most hormone contamination from the farms' livestock was due to the estrogen hormones E1 (1.38-97.10 ng/g), βE2 (10.08-1366 ng/g), and EE2 (1.50-99.92 ng/g), which originate from the natural excretion and admixture of steroids in feedstock or medicines. Steroid hormones were not detected in the wastewater from cleaning processes on farms with wastewater treatment plants, whereas farms without wastewater treatment plants showed high values of estrogen hormone contamination, with EEQs of 128.8-472.9 ng/L and RQs of 208.3-294.3. However, the analysis of steroid hormone residues in Phayao Lake demonstrated that the residues did not severely affect aquatic organisms (with RQs of 0.002-144.5), and no estrogen or androgen residues were observed in the water treatment plant or tap water.

Investigation of chlorinated phenols sorption mechanisms on different layers of the Danube alluvial sediment

The characteristics of the Danube river alluvial sediment are of great importance in assessing the risk for transport of pollutants to drinking water sources. Characterization of the sediment column layers has shown that the alluvial sediment, sampled near the city of Novi Sad, is a mesoporous sandy material with certain differences in the properties of individual layers. In order to investigate the sorption mechanisms of four chlorinated phenols (CPs) on the alluvial deposit, static sorption experiments were performed at pH 4, 7 and 10. The results of sorption experiments, confirmed by principal components analysis sugest different mechanisms govern the sorption process at different pH conditions. This can be attributed to the molecular characteristics of CPs, geosorbent properties and to variations in the surface charge of the sorbent at different pH conditions.

Adsorption of phenol and bisphenol A on river sediments: Effects of particle size, humic acid, pH and temperature

Phenolic Endocrine Disrupting Chemicals (EDCs) have drawn more and more interest due to their prevalence and persistence in aquatic environment. To study the adsorption of various phenolic EDCs on river sediments under natural conditions, we first sought to analyze the distribution characteristics of phenol and bisphenol A (BPA) in sediment from the Bahe River. The static adsorption experiments contained either single- or dual-contaminant of phenol and/or BPA in the system; they were conducted to characterize the adsorption of these two pollutants in the surface sediments and the main factors affecting the adsorption processes of the dual-contaminant system, including particle size, humic acid (HA) concentration, pH, and temperature. Results showed that in certain seasons, there was a significant correlation between the levels of phenol and BPA in Bahe sediments. When comparing the adsorption behaviors of phenol and BPA on sediments in single- and dual-contaminant systems, we found that the phenol adsorption behavior varied, while that of BPA remained consistent across the different systems. Moreover, different effects were observed with regards to a single factor and the interaction of multiple factors on the adsorption of pollutants. Of the four single factors, only HA concentration had a significant effect on the phenol adsorption in sediment. When considering the interaction of multiple factors, the interaction between HA concentration and temperature significantly promoted the adsorption of phenol. The influence of factors on the adsorption of BPA was in the following order: particle size > HA concentration > pH > temperature. Particle size significantly inhibited BPA adsorption in the sediment, while the interaction between particle size and pH increased BPA adsorption.

Adsorption of naturals hormones estrone, 17β-estradiol, and estriol by rice husk: monocomponent and multicomponent kinetics and equilibrium

In the present study, the use of the rice husk biomass as an alternative biosorbent for treating the estrone, 17 β-estradiol, and estriol hormones in monocomponent and multicomponent systems was investigated. The high-performance liquid chromatography technique (HPLC-UV) was applied in order to quantify the hormones, validating this method according to ANVISA and INMETRO. The biosorbent presented functional groups typical of cellulose, hemicellulose, lignin, and proteins, with an amorphous, fibrous, and porous surface. The best performance was obtained with a neutral pH and at room temperature (25[Formula: see text]C). The equilibrium times in batch systems were 60  min for the estrone, and 120 min for 17 βestradiol and estriol. The monocomponent kinetics of adsorption of estrone and estriol were adequately described by the pseudo-first-order model, whereas for the 17 β estradiol both pseudo-first-order and pseudo-second-order models well described the experimental data. For the multicomponent system, the kinetics of adsorption was appropriately represented by the pseudo-first-order model, demonstrating that the number of active sites was the limiting factor of the process. The monocomponent adsorption isotherms were adequately fitted by the Langmuir model, reaching adsorption capacities of 2.698, 1.649, and 0.979 mg g^-1 for the estrone, 17 βestradiol, and estriol hormones, respectively. The ternary isotherm models did not represent the experimental data, indicating that there was no competition among the hormones. The reactions presented favourable and spontaneous characteristics. The rice husk biomass showed a great potential as an adsorbent when treating effluents contaminated with hormones.

Sorption, transport, and transformation of natural and synthetic progestins in soil-water systems

Natural and synthetic progestins are emerging endocrine disruptors that can be transported from livestock farms and agricultural fields to receiving waters via surface runoff. The transformation of progestins during transport is expected to affect the efficiencies of runoff management systems. Therefore, this study explored the sorption, transport, and transformation of progesterone, norethisterone acetate, medroxyprogesterone acetate, cyproterone acetate, dydrogesterone, and norethisterone in agricultural soil-water systems. The sorption coefficients and retardation factors (R) were positively correlated with the progestin hydrophobicities, indicating that hydrophobic interactions dominated the sorption and transport processes. During transport, dydrogesterone and progesterone were transformed into 9-10 products. The breakthrough curves of the parents and products exhibited periodical patterns over extended times. Specifically, the R values of the parents and products were positively correlated with chromatographic retention times (hydrophobicities) when the products were generated before transport. In contrast, a negative correlation (R² = 0.75-0.88) was observed when products were successively generated during transport, indicating that the transformation kinetics changed the retardation of these solutes in the columns. These observations also demonstrated that the transport potential estimates based on traditional metrics of steroid hydrophobicity are not always accurate and that runoff management measures are less effective for metastable progestins.

The hitchhiker's guide to core samples: Key issues and lessons learned

Core samples may be used as valuable geochronometers for storing historical pollution footprints of organic pollutants. A number of studies have used core samples to evaluate temporal depositions, loading inventories, and effectiveness of environmental mitigation measures. However, in order to get a reliable estimation, certain prerequisites must be satisfied to rule out various confounding factors such as biomixing and melting. This review aims to understand when core samples can or cannot be used as natural archives for organic pollutants. First, we systematically review existing studies of organic pollutants in soil, sediment and ice cores and possible factors that may influence post-depositional fate of chemicals. Then, building on field evidence, model simulation and laboratory leaching tests findings, we discuss issues of post-depositional downward movement in detail. To assist future core sample studies, we summarize lessons learned on study design in the context of sampling design, data analysis, and data reporting. In particular, the combination of a careful study design and appropriate numerical model(s) will help to elevate core samples as a more reliable tool for retrospective understanding of chemical pollution. This review is an initial step toward a better and more accurate use of core samples, and further interdisciplinary cooperation is needed to develop standardized protocols, guidelines and tools.

Occurrence, sorption, and transformation of free and conjugated natural steroid estrogens in the environment

Natural steroid estrogens (NSEs), including free estrogens (FEs) and conjugated estrogens (CEs), are of emerging concern globally among public and scientific community due to their recognized adverse effects on human and wildlife endocrine systems in recent years. In this review, the properties, occurrence, sorption process, and transformation pathways of NSEs are clarified in the environment. The work comprehensively summarizes the occurrence of both free and conjugated estrogens in different natural and built environments (e.g., river, WWTPs, CAFOs, soil, and sediment). The sorption process of NSEs can be impacted by organic compounds, colloids, composition of clay minerals, specific surface area (SSA), cation exchange capacity (CEC), and pH value. The degradation and transformation of free and conjugated estrogens in the environment primarily involves oxidation, reduction, deconjugation, and esterification reactions. Elaboration about the major, subordinate, and minor transformation pathways of both biotic and abiotic processes among NSEs is highlighted. The moiety types and binding sites also would affect deconjugation degree and preferential transformation pathways of CEs. Notably, some intermediate products of NSEs still remain estrogenic potency during transformation process; the elimination of total estrogenic activity needs to be addressed in further studies. The in-depth researches regarding the behavior of both free and conjugated estrogens are further required to tackle their contamination problem in the ecosystem. Graphical abstract ᅟ.

Watershed scale patterns in steroid hormones composition and content characters at a typical eutrophic lake in southeastern China

Natural steroid hormones in the aquatic environment have attracted increasing attention because of their strong endocrine disrupting potency. Seven steroid hormones (estrone, 17α-estradiol, 17β-estradiol, estriol, testosterone, androstenedione, and progesterone) were analyzed from surface water and sediment sampled from Chaohu Lake, its upstream rivers (the Hangbu River, Nanfei River, Shiwuli River, and Pai River), drainage from the adjacent farmland, and treated and untreated municipal sewage. Concentrations of the seven target steroid hormones ranged from below the detection limit (ND) to 69.5 ng L^-1 in the water of Chaohu Lake and the upstream rivers. Three steroids-estrone, estriol, and 17α-estradiol-were found in relatively high residual concentrations in the water, with maximum concentrations of 69.5 ng L^-1, 51.5 ng L^-1, and 23.3 ng L^-1, respectively. All of the target steroid hormones except estriol were detected in the sediment in concentrations of ND-16344 ng kg^-1. The dominant steroid hormone in the sediment of Chaohu Lake and the upstream rivers was 17α-estradiol. In the Shiwuli River and the Pai River, the dominant steroid hormones (estrone and estriol) were the same as those in the untreated municipal sewage. This confirmed the deduction that untreated municipal sewage was the major source of steroid hormone residues in these two rivers. The main steroid hormone in the water of the Hangbu River and Chaohu Lake was 17α-estradiol, the same as that in the farmland drainage. In addition, 17α-estradiol was verified as the major factor in the contribution of farmland drainage to the pollution in these rivers. The water in the Nanfei River had high concentrations of estriol and 17α-estradiol. This indicates that both untreated municipal sewage and farmland drainage were the major sources. The discharge of steroid hormones from the four rivers to Chaohu Lake was approximately 75.1 kg year^-1, with the highest contributor being 17α-estradiol (24 kg year^-1). Therefore, based on the results of this study, the farmland drainage should be controlled to reduce the steroid hormone pollution in Chaohu Lake.

Effect of particle size on adsorption of norfloxacin and tetracycline onto suspended particulate matter in lake

Aquatic systems are important sinks of antibiotics; however, their final destination has not been completely elucidated. Therefore, we investigated the adsorption behaviors of suspended particulate matter (SPM) in lakes to support the analysis of the migration and transformation of antibiotics in lacustrine environments. SPM was collected from Meiliang Bay (ML) and Gonghu Bay (GH) in Lake Taihu, China, which was sieved into four particle sizes of >300, 150-300, 63-150, and <63 μm for subsequent antibiotic adsorption experiments. All particles exhibited rapid and substantial adsorption of tetracycline and norfloxacin. Most size fractions fit a Langmuir model, indicative of monomolecular adsorption, except the <63-μm fraction, which fit a Freundlich model. Particle size had a substantial influence on antibiotic adsorption; the 63-150-μm fraction had the greatest adsorption capacity, while the >300-μm fraction had the lowest capacity. The influence of particle size on adsorption was mainly related to SPM physicochemical properties, such as cation exchange capacity, surface area, and organic matter content, rather than types of functional groups. Considering the mass ratios, the <63-μm fraction had the greatest contribution to adsorption. Antibiotics adsorbed onto the SPM from ML and GH exhibited different behaviors. The ML SPM settled more readily into sediment, and larger, denser particles were more resistant to resuspension. Conversely, the GH SPM was more likely to be found in the water column, and larger, less-dense particles remained in the water column. These results help improve our understanding of the interactions between SPM and antibiotics in aquatic systems.

Sediment pollution in an urban water supply lake in southern Brazil

Urbanization and anthropogenic activities create many environmental issues in urban water supply reservoirs, especially in metropolitan regions. Thus, this study was carried out aiming to evaluate the variance in the physical-chemical characteristics of bottom sediment along the Lake Guaíba, Brazil. Lake Guaíba is a freshwater lake situated in a metropolitan region in southern Brazil, being the main water supply to the region. Surface sediment was evaluated to pH, electrical conductivity, particle-size, total organic carbon and nitrogen, metals and inorganic elements (Fe, Al, Ca, Ba, Sr, Co, Tl, Zn, Cu, Cr, Ni, Pb, Cd, and Hg), and organic compounds. The sediments in the Lake Guaíba show a wide range in the physical-chemical characteristics. Metals Zn, Cu, Cr, and Ni appear in higher concentrations near to the margin of southern Porto Alegre, where there was also more clay plus silt. Sediments of Lake Guaíba have physical-chemical variability by the settle tendency and water flow from the riverine to lacustrine areas. The sediment in Lake Guaíba had a median of: Zn, 132; Cu, 78; Cr, 42; Ni, 28; Pb, 33; Cd, 0.3; and Hg, 0.07 μg/g. Bed sediments of Lake Guaíba are polluted with Zn, Cu, Cr, and Ni, major in the east margin (near to Porto Alegre). The potential toxic metals and organic compounds found in Lake Guaíba are commonly reported in urban regions around the world. Those elements and compounds derive from many anthropic activities, as industries, sewage, and vehicles. With diffuse sources in the region, the pollution control in Lake Guaíba is very complex.

Distribution of Anticancer Drugs in River Waters and Sediments of the Yodo River Basin, Japan

This article reviews the pollution status of anticancer drugs present in the Yodo River basin located in the Kansai district of Japan, covering both the soluble and insoluble (adsorbed on the river sediments and suspended solids) levels. Procedures ranging from sampling in the field and instrumental analytical methods to the data processing for mass balance estimation of the target basin are also described. All anticancer drugs concerned with this article were detected in sewage and river waters, where the presence of bicalutamide (BLT) was identified at considerably high concentrations (maximum 254 ng/L in the main stream, 151 ng/L in tributaries, and 1032 ng/L in sewage treatment plant (STP) effluents). In addition, sorption distribution coefficient (logKd) values showed a tendency to become higher in the silty sediments at Suita Bridge than in the sandy sediments at Hirakata Bridge; these trends were supported by the results of the laboratory-scale sorption experiment. STPs were concluded to be the main sources of the anticancer drug load in the river, and a mass flux evaluation revealed that the effect of attenuation in the river environment was small. The effectiveness of ozonation in the sewage treatment process for removal of these anticancer drugs was further confirmed. The present article should be of value for facilitating the environmental risk assessment of a wide range of drugs in a broader geographical area.

Seasonal variations of steroid hormones released by wastewater treatment plants to river water and sediments: Distribution between particulate and dissolved phases

Extensive environmental monitoring was conducted in an urban river impacted by multiple combined sewer overflows (CSOs) and wastewater treatment plant (WWTP) discharge points. Temporal and spatial distributions of dissolved and particulate steroids (progesterone (Prog), testosterone (Testo), medroxyprogesterone (MDRXY-Prog), levonorgestrel (Levo), norethindrone (Nore), estrone (E1), estradiol (E2), estriol (E3), and 17α-ethinylestradiol (EE2)) were investigated in sewage, WWTP effluents, receiving river water and sediments, and in drinking water plant (DWP) intakes. Steroids were detected in both dissolved and particulate phases with mean concentrations from 21ngL^-1 to 389ngL^-1 in raw sewage and from 10ngL^-1 to 296ngL^-1 in treated wastewater. The particle-associated steroids represented 0-82% of their total concentration as some steroids like E1 and E3 were detected only in the dissolved phase while MDRXY-Prog (81%), Nore (71%), and EE2 (>75%) were primarily detected in the particulate phase. Particle-associated steroids were detected in spring samples from river water with mean concentrations ranging from 5.4ngL^-1 to 35.7ngL^-1 compare to 3ngL^-1 to 6.8ngL^-1 in summer samples. Levels of particle-associated Testo, Nore, E2 and Levo in DWP intakes (406.2-13,149.1ngg^-1) were similar to those found in raw sewage (336.6-7628.8ngg^-1), indicating their persistence in the suspended phase from discharge points. Total steroids measured in sediments were in the range of 7-1213ngg^-1, 5-25ngg^-1, and 22-226ngg^-1 in autumn, spring, and summer, respectively. Our findings confirm the presence and seasonal variation of a mixture of particle-associated steroids in drinking water sources. The presence of high concentrations of a mixture of particle-associated steroids in DWP intakes highlight the need for highly effective particle-removal processes to eliminate these recalcitrant compounds during drinking water production. Finally, the detected concentrations raise concerns about their potential environmental effects.

Study on the removal of hormones from domestic wastewaters with lab-scale constructed wetlands with different substrates and flow directions

Eight wastewater samples from a university campus were analysed between May and July of 2014 to determine the concentration of 14 natural and synthetic steroid hormones. An on-line solid-phase extraction combined with ultra-high performance liquid chromatography coupled with mass spectrometry (on-line SPE-UHPLC-MS/MS) was used as extraction, pre-concentration and detection method. In the samples studied, three oestrogens (17β-estradiol, estrone and estriol), two androgens (boldenone and testosterone), three progestogens (norgestrel, progesterone and norethisterone) and one glucocorticoid (prednisone) were detected. The removal of hormones was studied in primary and secondary constructed wetland mesocosms. The porous media of the primary constructed wetlands were palm tree mulch. These reactors were used to study the effect of water flow, i.e. horizontal (HF1) vs vertical (VF1). The latter was more efficient in the removal of 17β-estradiol (HF1: 30%, VF1: 50%), estrone (HF1: 63%, VF1: 85%), estriol (100% both), testosterone (HF1: 45%, VF1: 73%), boldenone (HF1:-77%, VF1: 100%) and progesterone (HF1: 84%, VF1: 99%). The effluent of HF1 was used as influent of three secondary constructed wetland mesocosms: two double-stage vertical flow constructed wetlands, one with gravel (VF2gravel) and one with palm mulch (VF2mulch), and a mineral-based, horizontal flow constructed wetland (HFmineral). VF2mulch was the most efficient of the secondary reactors, since it achieved the complete removal of the hormones studied with the exception of 17ß-estradiol. The significantly better removal of BOD and ammonia attained by VF2mulch suggests that the better aeration of mulch favoured the more efficient removal of hormones.

Occurrence, distribution, and sources of emerging organic contaminants in tropical coastal sediments of anthropogenically impacted Klang River estuary, Malaysia

This baseline assessment reports on the occurrence, distribution, and sources of emerging organic contaminants (EOCs) in tropical coastal sediments of anthropogenically impacted Klang River estuary, Malaysia. Bisphenol A was the highest concentration detected at 16.84 ng g^-1 dry weight, followed by diclofenac (13.88 ng g^-1 dry weight) and E1 (12.47 ng g^-1 dry weight). Five compounds, namely, amoxicillin, progesterone, diazinon, bisphenol A, and E1, were found in all sampling stations assessed, and other compounds such as primidone, diclofenac, testosterone, E2, and EE2 were ubiquitously present in sediment samples, with percentage of detection range from 89.04% to 98.38%. Organic carbon content and pH were the important factors controlling the fate of targeted compounds in the tropical estuarine sediment. On the basis of the literature from other studies, the sources of EOCs are thought to be from wastewater treatment plants, domestic/medical waste discharge, livestock activities, industrial waste discharge, and agricultural activities.

Response and recovery of fathead minnows (Pimephales promelas) following early life exposure to water and sediment found within agricultural runoff from the Elkhorn River, Nebraska, USA

Agricultural runoff is a non-point source of chemical contaminants that are seasonally detected in surface water and sediments. Agrichemicals found within seasonal runoff can elicit endocrine disrupting effects in organisms as adults, juveniles and larvae. The objectives of this study were (1) to determine if exposure to water, sediment or the water-sediment combination collected from an agricultural runoff event was responsible for changes in endocrine-responsive gene expression and development in fathead minnow larvae, and (2) whether such early life exposure leads to adverse effects as adults. Larvae were exposed during the first month post-hatch to water and sediment collected from the Elkhorn River and then allowed to depurate in filtered water until reaching sexual maturity, exemplifying a best-case recovery scenario. Gas chromatography mass spectrometry (GC/MS) analysis of the water and sediment samples detected 12 pesticides including atrazine, acetochlor, metolachlor and dimethenamid. In minnow larvae, exposure to river water upregulated androgen receptor gene expression whereas exposure to the sediment downregulated estrogen receptor α expression. Adult males previously exposed to both water and sediment were feminized through the induction of an ovipositor structure whereas no impacts were observed in other reproductive or sex characteristic endpoints for either sex based on exposure history. Results from this study indicate that both water and sediments found in agricultural runoff elicit responses from minnow larvae, and larvae can recover following early life exposure under a best-case scenario.

Steroid bioaccumulation profiles in typical freshwater aquaculture environments of South China and their human health risks via fish consumption

More attention was previously paid to adverse effects of steroids on aquatic organisms and their ecological risks to the aquatic environment. So far, little information has been reported on the bioaccumulative characteristics of different classes of steroids in cultured fish tissues. The present study for the first time provided a comprehensive analysis of the occurrence, bioaccumulation, and global consumers' health risks via fish consumption of androgens, glucocorticoids and progestanges in typical freshwater cultured farms in South China. The numbers and total concentrations of steroids detected in the tissues of five common species of the cultured fish were in the order of plasma > bile > liver > muscle and plasma > bile, muscle > liver, respectively. The field bioaccumulation factors for the detected synthetic steroids ranged from 450 to 97,000 in bile, 450 to 65,000 in plasma, 2900 to 16,000 in liver, and 42 to 2600 in muscle of fish, respectively. This data suggests that steroids are bioaccumulative in fish tissues. Mostly important, 4-androstene-3,17-dione (AED) and cortisone (CRN) were found to be reliable chemical indicators to predict the levels of steroids in plasma and muscle of the inter-species cultured fish, respectively. Furthermore, the maximum hazard quotients (HQs) of testosterone and progesterone were 5.8 × 10^-4 and 9.9 × 10^-5, suggesting that human health risks were negligible via ingestion of the steroids-contaminated fish.

Distribution of six anticancer drugs and a variety of other pharmaceuticals, and their sorption onto sediments, in an urban Japanese river

The distributions of 31 pharmaceuticals grouped into nine therapeutic classes, including six anticancer drugs, were investigated in the waters and sediments of an urban river in Japan. The coefficients of sorption (logK _d) to the river sediments were also determined from the results of a field survey and laboratory-scale experiment. Three anticancer drugs-bicalutamide, doxifluridine, and tamoxifen-were detected in the river sediments at maximum concentrations of 391, 392, and 250 ng/kg, respectively. In addition, the transformation products of psychotropic carbamazepine (2-hydroxy carbamazepine, acridine, and acridone) were detected in the range of 108 ng/kg (2-hydroxy carbamazepine) to 2365 ng/kg (acridine), and the phytoestrogen glycitein was detected in the range of N.D. to 821 ng/kg. The logK _d values of the targeted pharmaceuticals in river sediments in the field survey ranged from 0.5 (theophylline) to 3.3 (azithromycin). These results were in accord with those of the laboratory-scale sorption experiment. To the best of our knowledge, this is the first report of the detection of the anticancer drugs bicalutamide and tamoxifen, the transformation products of carbamazepine (2-hydroxy carbamazepine, acridine, and acridone), and the phytoestrogen genistein in river sediments.

Sediment and salinity effects on the bioaccumulation of sulfamethoxazole in zebrafish (Danio rerio)

The dynamic distribution of a widely used antibiotic sulfamethoxazole between water, sediment and aquatic organisms (zebrafish) was studied in microcosms. Sulfamethoxazole concentrations in water were gradually reduced, while in sediment and zebrafish gradually increased, suggesting active adsorption and bioaccumulation processes occurring. The presence of sediment particles and their interactions with water reduced the bioaccumulation of sulfamethoxazole in zebrafish by 13-28%. The sediment of smaller particle size with more organic carbon content and higher surface area, adsorbed sulfamethoxazole more extensively and decreased its bioaccumulation most significantly. The effect became more severe with increasing salinity in water due to the salting out of sulfamethoxazole, resulting in 24-33% reduction in bioaccumulation. At equilibrium, the distribution of sulfamethoxazole in different phases was quantified, with most sulfamethoxazole being associated with water (97.3%), followed by sedimentary phase (2.7%) and finally zebrafish (0.05%). The findings provided important data for further research into antibiotics fate and bio-uptake in aquatic organisms, and subsequent ecotoxicity.

Effect of rainfall timing and tillage on the transport of steroid hormones in runoff from manure amended row crop fields

Runoff generated from livestock manure amended row crop fields is one of the major pathways of hormone transport to the aquatic environment. The study determined the effects of manure handling, tillage methods, and rainfall timing on the occurrence and transport of steroid hormones in runoff from the row crop field. Stockpiled and composted manure from hormone treated and untreated animals were applied to test plots and subjected to two rainfall simulation events 30days apart. During the two rainfall simulation events, detection of any steroid hormone or metabolites was identified in 8-86% of runoff samples from any tillage and manure treatment. The most commonly detected hormones were 17β-estradiol, estrone, estriol, testosterone, and α-zearalenol at concentrations ranging up to 100-200ngL^-1. Considering the maximum detected concentrations in runoff, no more than 10% of the applied hormone can be transported through the dissolved phase of runoff. Results from the study indicate that hormones can persist in soils receiving livestock manure over an extended period of time and the dissolved phase of hormone in runoff is not the preferred pathway of transport from the manure applied fields irrespective of tillage treatments and timing of rainfall.

Fate of new three anti-influenza drugs and one prodrug in the water environment

We evaluated the environmental fate of new three anti-influenza drugs, favipiravir (FAV), peramivir (PER), and laninamivir (LAN), and an active prodrug of LAN, laninamivir octanoate (LANO), in comparison with four conventional drugs, oseltamivir (OS), oseltamivir carboxylate (OC), amantadine (AMN), and zanamivir (ZAN) by photodegradation, biodegradation, and sorption to river sediments. In addition, we conducted 9-month survey of urban rivers in the Yodo River basin from 2015 to 2016 (including the influenza season) to investigate the current status of occurrence of these drugs in the river environment. The results clearly showed that FAV and LAN rapidly disappeared through photodegradation (half-lives 1 and 8 h, respectively), followed by LANO which gradually disappeared through biodegradation (half-life, 2 days). The remained PER and conventional drugs were, however, persistent and transported from upstream to downstream sites. Rates of their sorption to river sediments were negligibly small. Detected levels remained were in the range from N.D. to 89 ng/L for the river waters and from N.D. to 906 ng/L in sewage effluent. However, all of the remained drugs were effectively removed by ozonation after chlorination at a sewage treatment plant. These findings suggest the importance of introducing ozonation for reduction of pollution loads in rivers, helping to keep river environments safe. To the best of our knowledge, this is the first evaluation of the removal effects of natural sunlight, biodegradation, and sorption to river sediments on FAV, PER, LAN, LANO, and a conventional drug, AMN.

Stereoselective Degradation of Estradiol and Trenbolone Isomers in Alluvial Sediment

Stereoisomers of estradiol (E2) or trenbolone (TB) can occur together in the environment receiving human or livestock wastes. However, the effect of their co-occurrence on persistence has not been well elucidated. A sandy and a silt loam sediment were used to establish microcosms with α- and β-isomers of E2 or TB spiked individually and together. Sediments were sampled periodically and analyzed for E2 and TB isomers and their transformation products using derivatization gas chromatography-mass spectrometry. Results showed that stereoselective degradation was significant for E2 in both sediments and TB in the sandy sediment with β-isomers decaying more rapidly than α-isomers. In the sandy sediment containing limited natural organic carbon and nutrients, co-occurrence of both isomers of either E2 or TB decreased the dissipation rates. In the silt loam sediment with abundant organic matter and nutrients, the decay rates of both isomers were not changed in the presence of the other isomer. Estrone (E1) and trendione (TD) were detected as primary metabolites of E2 and TB isomers, respectively. The formation and decay profiles of E1 were similar in both sediments with 92-100% of E2 transformed to E1. The TD profiles were different across sediments with ∼100% of TB transformed to TD except in the sandy sediment where 51-60% of 17α-TB was converted to TD. These results indicate that the transformation processes of steroid hormone are stereoselective in sediment and co-occurrence of stereoisomers can prolong steroid persistence and thus pose greater environmental risk.

Impact of sediment particle size on biotransformation of 17β-estradiol and 17β-trenbolone

Soil/sediment particle size has been reported to influence the sorption and bioavailability of steroid hormones in the environment. However, the impact of particle size on biotransformation has not been well elucidated. The present study investigated the dissipation of 17β-estradiol and 17β-trenbolone and the formation and degradation of the subsequent transformation products in different size fractions of a sandy and a silt loam sediment. The results showed that the decay of 17β-estradiol and 17β-trenbolone associated with fine particles followed a biphasic pattern with more rapid decay in the initial phase followed by a second phase with slower decay of the residues compared to their decay rates in the sand fraction. Estrone and trendione were detected as a primary biotransformation product for 17β-estradiol and 17β-trenbolone, respectively. The parent-to-product conversion ratios and the degradation rates of estrone and trendione varied among different size fractions, but no consistent correlation was observed between decay rates and sediment particle size. Estrone and trendione decayed in the whole sediments at rates not statistically different from those associated with the fine fractions. These results indicate that fine particles may play an important role in influencing the persistence of and the potential risk posed by steroid hormones in the aquatic systems.

Bioavailability and Fate of Sediment-Associated Progesterone in Aquatic Systems

The environmental fate and bioavailability of progesterone, a steroid hormone known to cause endocrine-disrupting effects in aquatic organisms, is of growing concern due to its occurrence in the environment in water and sediment influenced by wastewater treatment plant and paper mill effluents, as well as livestock production. The objective of this study was to evaluate the fate of progesterone in two natural sediments and the corresponding alteration of gene expression in three steroid-responsive genes; vitellogenin, androgen receptor and estrogen receptor alpha. When exposed to progesterone-spiked sand, fathead minnows (Pimephales promelas) exhibited significant reductions in the expression of vitellogenin and androgen receptor expression. In contrast, fish exposed to progesterone associated with the silty loam sediment did not show a biological response at 7 days and only realized a significant reduction in vitellogenin. In both sediments, progesterone degradation resulted in the production of androgens including androsteinedione, testosterone, and androstadienedione, as well as the antiestrogen, testolactone. Differences in compound fate resulted in organism exposure to different suites of metabolites either in water or associated with the sediment. Results from this study suggest that environmental progestagens will lead to defeminization at environmentally relevant concentrations, and that exposure is influenced by sediment properties.