Occurrence and implications of estrogens and xenoestrogens in sewage effluents and receiving waters from South East Queensland

We report a survey on the occurrence of estrogens (estrone, E1; 17β-estradiol, E2; 17α-ethynylestradiol, EE2) and xenoestrogens (bisphenol-A, BPA; 4-t-octylphenol, 4-t-OP; 4-nonylphenols, 4-NP; and nonylphenol mono- and di-ethoxylates, NPE1 and NPE2) in effluents from five wastewater treatment plants and their receiving waters in South East Queensland. The total xenoestrogen concentrations in effluent ranged between 2446 ng/L and 6579 ng/L, with 4-NP and NPE1-2 having much higher concentration levels than BPA and 4-t-OP. The estrogen levels in effluent varied from 9.12 to 32.22 ng/L for E1, from 1.37 ng/L to 6.35 ng/L for E2 and from 0.11 ng/L to 1.20 ng/L for EE2. No significant differences (p < 0.05) in the concentrations of the selected estrogenic compounds were found for the effluents from the five sewage treatment plants. The estrogens and xenoestrogens were also found in the receiving waters at relatively lower concentration levels due to dilution of effluents in the rivers. Based on the chemical analysis data and relative potency of the compound from in vitro and in vivo bioassays from the literature, the calculated in vitro EEQ values (estrogen equivalents) in the receiving river waters downstream of the effluent discharge points ranged from 1.32 to 11.79 ng/L, while the in vivo EEQ values (vitellogenin response in rainbow trout) ranged from 2.48 to 21.18 ng/L. The three estrogens accounted for the majority of the EEQ in the water samples. This study indicates that the rivers of South East Queensland are at potential risk.     

Analysis of environmental endocrine disrupting chemicals using the E-screen method and stir bar sorptive extraction in wastewater treatment plant effluents

Endocrine disrupting chemicals (EDCs) have become a major issue in the field of environmental science due to their ability to interfere with the endocrine system. Recent studies show that surface water is contaminated with EDCs, many released from wastewater treatment plants (WWTP). This pilot study used biological (E-screen assay) and chemical (stir bar sorptive extraction-GC-MS) analyses to quantify estrogenic activity in effluent water samples from a municipal WWTP and in water samples of the recipient river, upstream and downstream of the plant.The E-screen assay was performed on samples after solid phase extraction (SPE) to determine total estrogenic activity; the presence of estrogenic substances can be evaluated by measuring the 17-β-estradiol equivalency quantity (EEQ). Untreated samples were also assayed with an acute toxicity test (Vibrio fischeri) to study the correlation between toxicity and estrogenic disruption activity.Mean EEQs were 4.7 ng/L (± 2.7 ng/L) upstream and 4.4 ng/L (± 3.7 ng/L) downstream of the plant, and 11.1 ng/L (± 11.7 ng/L) in the effluent. In general the WWTP effluent had little impact on estrogenicity nor on the concentration of EDCs in the river water. The samples upstream and downstream of the plant were non-toxic or weakly toxic (0 < TU < 0.9) while the effluent was weakly toxic or toxic (0.4 < TU < 7.6). Toxicity and estrogenic activity were not correlated.At most sites, industrial mimics, such as the alkylphenols and phthalates, were present in higher concentrations than natural hormones. Although the concentrations of the detected xenoestrogens were generally higher than those of the steroids, they accounted for only a small fraction of the EEQ because of their low estrogenic potency. The EEQs resulting from the E-screen assay and those calculated from the results of chemical analyses using estradiol equivalency factors were comparable for all samples and closely correlated.     

The use of modelling to predict levels of estrogens in a river catchment: How does modelled data compare with chemical analysis and in vitro yeast assay results?

Effluent discharges at Rodbourne sewage treatment works (STWs) were assessed using chemical and in vitro biological analysis as well as modelling predictions. Results showed that Rodbourne STW discharged less estrone (E1) than expected, but similar 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2) to those predicted by a widely cited effluent prediction model. The Exposure Analysis Modelling System (EXAMS) model was set up using measured effluent concentrations as its starting point to predict estrogen concentrations along a 10 km length of the receiving water of the River Ray. The model adequately simulated estrogen concentrations along the river when compared to July 2007 measured data. The model predicted combined estrogen equivalents in reasonable agreement with estrogenicity as measured by passive sampler (POCIS) extracts using the yeast estrogen screen. Using gauged mean flow values for 2007 the model indicated that the most important determinand for estrogen exposure in the Ray was not season, but proximity to the Rodbourne effluent. Thus, fish in the first 3 km downstream of Rodbourne were typically exposed to two or even three times more estrogens than those living 7-10 km further downstream. The modelling indicated that, assuming the effluent estrogen concentrations measured in February 2008 were typical, throughout the year the whole length of the Ray downstream of Rodbourne would be estrogenic, i.e. exceeding the 1 ng/L E2 equivalent threshold for endocrine disruption.     

Comparing steroid estrogen, and nonylphenol content across a range of European sewage plants with different treatment and management practices

The effluent of 17 sewage treatment works (STW) across Norway, Sweden, Finland, The Netherlands, Belgium, Germany, France and Switzerland was studied for the presence of estradiol (E2), estrone (E1), ethinylestradiol (EE2) and nonylphenol (NP). Treatment processes included primary and chemical treatment only, submerged aerated filter, oxidation ditch, activated sludge (AS) and combined trickling filter with activated sludge. The effluent strength ranged between 87 and 846 L/PE (population equivalent), the total hydraulic retention time (HRT) ranged between 4 and 120 h, sludge retention time (SRT) between 3 and 30 d, and water temperature ranged from 12 to 21 °C. The highest estrogen values were detected in the effluent of the STW which only used primary treatment (13 ng/L E2 and 35 ng/L E1) and on one occasion in one of the STW using the AS system (6.5 ng/L E2, 50.5 ng/L E1, but on three other occasions the concentrations in this STW were at least a factor of 6 lower). For the 16 STW employing secondary treatment E2 was only detected in the effluent of six works during the study period (average 0.7-5.7 ng/L). E1 was detected in the effluent of 13 of the same STW. The median value for E1 for the 16 STW with secondary treatment was 3.0 ng/L. EE2 was only detected in two STW (1.1, <0.8-2.8 ng/L). NP could be detected in the effluent of all 14 STW where this measurement was attempted, with a median of 0.31 μg/L and values ranging from 0.05 to 1.31 μg/L. A comparison of removal performance for E1 was carried out following prediction of the probable influent concentration. A weak but significant (α<5%) correlation between E1 removal and HRT or SRT was observed.     

Removal of dissolved estrogen in sewage effluents by β-cyclodextrin polymer

Substances with estrogenic activity are found in effluents of municipal sewage plants and dairy farms. These effluents have the potential to induce feminization in male fish. In this study, cyclodextrin polymers (CDPs) that are insoluble in both polar and non-polar solvents were selected for the removal of dissolved estrogens in the effluent of a municipal sewage plant. The removal capacity of CDPs was high in the order of β-CDP ≥ γ-CDP ? α-CDP. The mechanism for adsorption of estrogens to β-CDP was not only due to a host-guest interaction as molecular recognition by β-cyclodextrin (β-CD), but also due to adsorption by the polymer matrix. β-CDP of 0.2% (w/v) removed 17β-estradiol (E2) of about 70% from 10⁻¹¹ mol/L, and more than 90% from ≥ 10⁻¹⁰ mol/L. The removal ratios of E2 in the presence of cholesterols, which are contained at higher concentrations than estrogens in sewage effluents and are adsorptive competitor for β-CDP, were about 85% at a cholesterol/E2 molar ratio of 100 and > 90% at molar ratios of 0.1, 1, and 10. The effluent from a municipal sewage plant had estrogenic activity corresponding to 5.5 × 10⁻¹¹ molE2/L by yeast two-hybrid assay. The estrogens in the effluent were also removed > 90% by the β-CDP treatment. Therefore, β-CDP is able to remove dissolved estrogens over a wide range of concentrations in the presence of various contaminants such as wastewaters.     

Destruction of estrogenic activity in water using UV advanced oxidation

The transformation of the steroidal Endocrine Disrupting Compounds (EDCs), 17-beta-estradiol (E2) and 17-alpha-ethinyl estradiol (EE2) by direct UV photolysis and UV/H(2)O(2) advanced oxidation was studied from the perspective of the removal of estrogenic activity associated with the compounds. First, experiments were performed to link the oxidation of E2 and EE2 with subsequent reduction in estrogenic activity. No statistically significant difference between removal rates was observed, implying that the oxidation products of E2 and EE2 are not as estrogenic (measured by the Yeast Estrogen Screen (YES)) as the parent compounds. Utilizing the YES, 90% removal of estrogenic activity of E2 and EE2 at environmentally relevant concentrations ( approximately 3 microg L(-1)) was achieved using a combination of 5 mg L(-1) H(2)O(2) and a UV fluence of less than 350 mJ cm(-2). Thus, these compounds, when considered at environmentally relevant levels, are significantly degraded at much lower UV fluences than previously thought. A steady state OH radical model was used to predict oxidation of EE2 in laboratory and natural waters.     

Importance of monsoon rainfall in mass fluxes of filtered and unfiltered mercury in Gwangyang Bay, Korea

We investigated the effects of the East Asian Summer Monsoon (EASM), which brings approximately half of Korea's annual rainfall in July, on the concentration and particle-water partitioning, and sources of Hg in coastal waters. Surface seawater samples were collected from eight sites in Gwangyang Bay, Korea, during the monsoon (July, 2009) and non-monsoon dry (April and November, 2009) seasons and the concentrations of suspended particulate matter, chlorophyll-a, and unfiltered and filtered Hg were determined. We found significant (p < 0.05) increases in filtered Hg in the monsoon season (1.8 ± 0.019 pM) compared to the dry season (0.62 ± 0.047 pM). In contrast, the Hg concentrations associated with particles showed no significant differences (p > 0.05) between the monsoon (459 ± 141 pmol g^− 1) and the dry season (346 ± 30 pmol g^− 1), which resulted in decreased particle-water partition coefficients of Hg in the monsoon season compared to the values in the dry season: 5.7 ± 0.1 in April, 5.3 ± 0.1 in July, and 5.8 ± 0.1 in November. The annual Hg input to Gwangyang Bay was estimated at 64 ± 6.6 mol yr^− 1 and 27 ± 1.9 mol yr^− 1 for unfiltered and filtered Hg, respectively. The Hg discharged from rivers was a major source of Hg in Gwangyang Bay: the river input contributed 83 ± 13% of total input of unfiltered and 73 ± 6.0% of filtered Hg. On a monthly basis, unfiltered Hg input was 17 ± 11 mol month^− 1 in the monsoon season and 3.2 ± 0.70 mol month^− 1 in the dry season, while filtered Hg input was 7.1 ± 4.1 mol month^− 1 in the monsoon and 1.3 ± 0.26 mol month^− 1 in the dry. Consequently, the EASM resulted in an unfiltered Hg input 5.3 times greater than the mean dry month input and a filtered Hg input 5.5 times greater than the mean dry month input, which is mainly attributable to enhanced river water discharge during the monsoon season.     

Steroid hormones in biosolids and poultry litter: a comparison of potential environmental inputs

Steroid hormones can act as potent endocrine disruptors when released into the environment. The main sources of these chemicals are thought to be wastewater treatment plant discharges and waste from animal feeding operations. While these compounds have frequently been found in wastewater effluents, few studies have investigated biosolids or manure, which are routinely land applied, as potential sources. This study assessed the potential environmental contribution of steroid hormones from biosolids and chicken litter. Hormone concentrations in samples of limed biosolids collected at a waste treatment plant over a four year period ranged from < 2.5 to 21.7 ng/g dry weight for estrone (E1) and < 2.5 to 470 ng/g dry weight for progesterone. Chicken litter from 12 mid-Atlantic farms had averages of 41.4 ng/g dry weight E1, 63.4 ng/g dry weight progesterone, and 19.2 ng/g dry weight E1-sulfate (E1-S). Other analytes studied were 17β-estradiol (E2), estriol (E3), 17α-ethinylestradiol (EE2), testosterone, E2-3-sulfate (E2-3-S), and E2-17-sulfate (E2-17-3).     

Occurrence of androgens and progestogens in wastewater treatment plants and receiving river waters: Comparison to estrogens

Research has shown that exposure to androgens and progestogens can cause undesirable biological responses in the environment. To date, however, no detailed or direct study of their presence in wastewater treatment plants has been conducted. In this study, nine androgens, nine progestogens, and five estrogens were analyzed in influent and final effluent wastewaters in seven wastewater treatment plants (WWTPs) of Beijing, China. Over a period of three weeks, the average total hormone concentrations in influent wastewaters were 3562 (Wujiacun WWTP)-5400 ng/L (Fangzhuang WWTP). Androgens contributed 96% of the total hormone concentrations in all WWTP influents, with natural androgen (androsterone: 2977 ± 739 ng/L; epiandrosterone: 640 ± 263 ng/L; and androstenedione: 270 ± 132 ng/L) being the predominant compounds. The concentrations of synthetic progestogens (megestrol acetate: 41 ± 25 ng/L; norethindrone: 6.5 ± 3.3 ng/L; and medroxyprogesterone acetate: 6.0 ± 3.2 ng/L) were comparable to natural ones (progesterone: 66 ± 36 ng/L; 17α,20β-dihydroxy-4-progegnen-3-one: 4.9 ± 1.2 ng/L; 21α-hydroxyprogesterone: 8.5 ± 3.0 ng/L; and 17α-hydroxyprogesterone: 1.5 ± 0.95 ng/L), probably due to the wide and relatively large usage of synthetic progestogens in medical therapy. In WWTP effluents, androgens were still the dominant class accounting for 60% of total hormone concentrations, followed by progestogens (24%), and estrogens (16%). Androstenedione and testosterone were the main androgens detected in all effluents. High removal efficiency (91-100%) was found for androgens and progestogens compared with estrogens (67-80%), with biodegradation the major removal route in WWTPs. Different profiles of progestogens in the receiving rivers and WWTP effluents were observed, which could be explained by the discharge of a mixture of treated and untreated wastewater into the receiving rivers.     

Fate simulation and risk assessment of endocrine disrupting chemicals in a reservoir receiving recycled wastewater

A fugacity based model was applied to simulate the distribution of three endocrine disrupting chemicals (EDCs), namely estrone (E1), 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) in a reservoir receiving recycled wastewater in Australia. At typical conditions, the majority of estrogens were removed by degradation in the water compartment. A sensitivity analysis found that the simulated concentrations of E1, E2 and EE2 were equally sensitive to the parameters of temperature (T), reservoir water volume (V) and equivalent biomass concentration (EBC), but E1 was more sensitive to estrogen concentration in the recycled water (C_e) and recycling rate (F_r). In contrast, all three estrogens were not sensitive to reservoir water releasing rate (F_d). Furthermore, a probabilistic health risk assessment showed that the simulated concentrations were below fish exposure threshold value (ETV) and human public health standard (PHS). Human equivalent dose of EDCs from fish consumption was about 10 times higher than that from drinking water consumption. The highest risk quotient among the three estrogens was found for EE2 with less than 9.5 × 10⁻², implying negligible health risks.     

Invertebrate mercury bioaccumulation in permanent, seasonal, and flooded rice wetlands within California's Central Valley

We examined methylmercury (MeHg) bioavailability in four of the most predominant wetland habitats in California's Central Valley agricultural region during the spring and summer: white rice, wild rice, permanent wetlands, and shallowly-flooded fallow fields. We sampled MeHg and total mercury (THg) concentrations in two aquatic macroinvertebrate taxa at the inlets, centers, and outlets of four replicated wetland habitats (8 wetlands total) during two time periods bounding the rice growing season and corresponding to flood-up and pre-harvest (96 total samples). In general, THg concentrations (mean ± standard error) in Notonectidae (Notonecta, back swimmers; 1.18 ± 0.08 µg g^− 1 dry weight [dw]) were higher than in Corixidae (Corisella, water boatmen; 0.89 ± 0.06 µg g^− 1 dw, MeHg: 0.74 ± 0.05 µg g^− 1 dw). MeHg concentrations were correlated with THg concentrations in Corixidae (R² = 0.80) and 88% of THg was in the MeHg form. Wetland habitat type had an important influence on THg concentrations in aquatic invertebrates, but this effect depended on the sampling time period and taxa. In particular, THg concentrations in Notonectidae, but not Corixidae, were higher in permanent wetlands than in white rice, wild rice, or shallowly-flooded fallow fields. THg concentrations in Notonectidae were higher at the end of the rice growing season than near the time of flood-up, whereas THg concentrations in Corixidae did not differ between time periods. The effect of wetland habitat type was more prevalent near the end of the rice growing season, when Notonectidae THg concentrations were highest in permanent wetlands. Additionally, invertebrate THg concentrations were higher at water outlets than at inlets of wetlands. Our results indicate that although invertebrate THg concentrations increased from the time of flood-up to draw-down of wetlands, temporarily flooded habitats such as white rice, wild rice, and shallowly-flooded fallow fields did not have higher THg or MeHg concentrations in invertebrates than permanent wetlands.     

Selected personal care products and endocrine disruptors in biosolids: an Australia-wide survey

Personal care products (PCPs) and endocrine disrupting compounds (EDCs) are groups of organic contaminants that have been detected in biosolids around the world. There is a shortage of data on these types on compounds in Australian biosolids, making it difficult to gain an understanding of their potential risks in the environment following land application. In this study, 14 biosolids samples were collected from 13 Australian wastewater treatment plants (WWTPs) to determine concentrations of eight compounds that are PCPs and/or EDCs: 4-t-octylphenol (4tOP), 4-nonylphenol (4NP), triclosan (TCS), bisphenol A (BPA), estrone (E1), 17β-estradiol (E2), estriol (E3) and 17α-ethinylestradiol (EE2). Concentration data were evaluated to determine if there were any differences between samples that had undergone anaerobic or aerobic treatment. The concentration data were also compared to other Australian and international data. Only 4tOP, 4NP, TCS, and BPA were detected in all samples and E1 was detected in four of the 14 samples. Their concentrations ranged from 0.05 to 3.08 mg/kg, 0.35 to 513 mg/kg, < 0.01 to 11.2 mg/kg, < 0.01 to 1.47 mg/kg and < 45 to 370 μg/kg, respectively. The samples that were obtained from WWTPs that used predominantly anaerobic treatment showed significantly higher concentrations of the compounds than those obtained from WWTPs that used aerobic treatment. Overall, 4NP, TCS and BPA concentrations in Australian biosolids were lower than global averages (by 42%, 12% and 62%, respectively) and 4tOP concentrations were higher (by 25%), however, of these differences only that for BPA was statistically significant. The European Union limit value for NP in biosolids is 50 mg/kg, which 4 of the 14 samples in this study exceeded.     

Contribution of known endocrine disrupting substances to the estrogenic activity in Tama River water samples from Japan using instrumental analysis and in vitro reporter gene assay

To quantitatively characterize the substances contributing to estrogenic activity in river water, in vitro bioassay using MVLN cells and instrumental analysis using liquid chromatograph–mass spectrometer (LC/MS) or liquid chromatograph–tandem mass spectrometer (LC/MS/MS) were applied to river water extracts taken from various locations in the Tama River, Japan. Tama River water samples were extracted using solid phase extraction and the crude extracts were fractionated by high-performance liquid chromatography (HPLC) into 10 fractions. The sixth fraction contained nonylphenol (NP) and octylphenol (OP) at concentrations in the range of 51.6–147 and 6.9–81.9 ng/L, respectively (concentrations corresponding to the original sample volumes). No estrogenic activity, expressed as 17β-estradiol equivalents (E2-EQ_B), however, was observed in this fraction (<0.6 ng-E2eq/L). Instrumentally determined estrogenic activity (E2-EQ_C), which is the concentrations of NP and OP multiplied by their corresponding relative potency, was below the detection limit of the MVLN cell bioassay. Estrogenic activities were detected only in HPLC fraction nos. 7, 8 and 9. Estrone (E1), estradiol (E2) and bisphenol A (BPA) were detected in these fractions. Estriol (E3) and ethynylestradiol (EE2) were not detected (<0.2 ng/L) in these fractions. The calculated E2-EQ_C for BPA was below the detection limit of bioassay. The E2-EQ_C for E1 and E2 were on the same order as the estrogenic activity determined by the bioassay (E2-EQ_B). The ratios of E2-EQ_C and E2-EQ_B for E1 and E2 in the three factions collectively (nos. 7–9) were 0.49–0.97 and 0.29–1.12, respectively. Above results indicated that the major causal substances to the estrogenic activity in the Tama River were E1 and E2.     

Short-term exposure to the environmentally relevant estrogenic mycotoxin zearalenone impairs reproduction in fish

Zearalenone (ZON) is one of the worldwide most common mycotoxins and exhibits estrogenic activity in the range of natural steroid estrogens such as 17β-estradiol (E2). The occurrence of ZON has been reported in drainage water, soil, wastewater effluents and rivers, but its ecotoxicological effects on fish have hardly been investigated.In this study the estrogenic potency of the ZON was compared to E2 in a recombinant yeast estrogen screen (rYES) and the effects of waterborne ZON exposure on reproduction, physiology and morphology of zebrafish (Danio rerio) were investigated in a 42-day reproduction experiment. E2 as well as ZON evoked a sigmoid concentration-response curve in the rYES with a mean EC₅₀ of 2 and 500 μg/L, respectively, resulting in an E2:ZON EC₅₀ ratio of 1:250. Exposure to ZON for 21 days reduced relative spawning frequency at 1000 and 3200 ng/L to 38.9 and 37.6%, respectively, and relative fecundity at 100, 320, 1000 and 3200 ng/L to 74.2, 41.7, 43.8 and 16.7%, respectively, in relation to the 21-day pre-exposure period. A 4.4 and 8.1 fold induction of plasma vitellogenin (VTG) was observed in male zebrafish at 1000 and 3200 ng/L ZON, respectively. Exposure to ZON did not affect fertility, hatch, embryo survival and gonad morphology of zebrafish.The results of this study demonstrate that although ZON possesses a moderate estrogenic potency in vitro, it exhibits a comparably strong effect on induction of VTG and reproduction in vivo. This indicates that ZON might contribute to the overall estrogenic activity in the environment and could therefore pose a risk for wild fish in their natural habitat.     

Urinary excretion rates of natural estrogens and androgens from humans, and their occurrence and fate in the environment: A review

Endocrine disrupting compounds (EDCs) are pollutants with estrogenic or androgenic activities at very low concentrations and are emerging as a major concern for water quality. For sewage of municipal wastewater treatment plants in cities, one of the most important sources of EDCs are natural estrogens and natural androgens (NEAs) excreted from humans. Therefore, estrogenic/androgenic potencies or relative binding affinity of the NEAs were first outlined from different sources, and data of urinary excretion rates of NEAs were summarized. To evaluate their estrogenic activities, their excretion rates of estrogen equivalent (EEQ) or testosterone (T) equivalent (TEQ) were also calculated. Based on our summary, the total excretion rates of EEQ by estrone (E1), 17β-estradiol (E2), and estriol (E3) only accounted for 66-82% of the total excretion rate of EEQ among four different groups, and the other corresponding natural estrogens contributed 18-34%, which meant that some of the other natural estrogens may also exist in wastewater with high estrogenic activities. Based on the contribution ratio of individual androgens to the total excretion rate of TEQ, five out of 12 natural androgens, T, dihydrotestosterone (DHT), androsterone (AD), 5β-androstanediol (β-ADL), and androstenediol (ANL) were evaluated as the priority natural androgens, which may exist in wastewater with high androgenic activities. Published data on occurrence and fate of the NEAs including natural estrogen conjugates in the environment were also summarized here.     

Degradation of estrone in aqueous solution by photo-Fenton system

Photodegradation of estrone (E1) in aqueous solutions by UV-VIS/Fe(III)/H2O2 system (photo-Fenton system) was preliminarily investigated under a 250-W metal halide lamp (lambda > or = 313 nm). The influences such as initial pH value, initial concentration of Fe(III), H2O2 and E1 on degradation efficiency of E1 were discussed in detail. The results indicated that E1 could be decomposed efficiently in UV-VIS/Fe(III)/H2O2 system. After 160-min irradiation, the photodegradation efficiency of 18.5 micromol L(-1) E1 reached 98.4% in the solution containing 20.8 micromol L(-1) Fe(III), and 1664 micromol L(-1) H2O2 at initial pH value 3.0. The degradation efficiencies of E1 were dependent on initial pH value, Fe (III) concentration and H2O2 concentration. The degradation of four estrogens estrone (E1), estradiol (E2), 17alpha-ethynylestradiol (EE2) and diethylstibestrol (DES) in UV-VIS/Fe(III)/H2O2 system were also conducted. Under the conditions of pH 3.0, the E1 apparent kinetics equation -dC(E1)/dt=0.00093[H2O2]0.47[Fe(III)]0.63[E1]0.24 (r=0.9935, n=11) was obtained. The E1 mineralization efficiency was lower than degradation efficiency under the same conditions, which implied the mineralization occurred probably only at aromatic ring. There are several intermediate products produced during the course of E1 degradation. The comparison of the degradation efficiencies of E1, E2, EE2 and DES degradation in UV-VIS/Fe(III)/H2O2 system were also conducted, and the relative degradability among different estrogens were followed the sequence: DES>E2>EE2>E1.     

Identification of estrogen-like effects and biologically active compounds in river water using bioassays and chemical analysis

The Nackdong River is the longest river in South Korea and passes through major cities that have several industrial complexes, including chemical, electric, and petrochemical complexes, and municipal characteristics such as apartment complexes. Along the river, the Gumi region has an electric industrial complex and an apartment complex that may be possible point sources of xenoestrogens such as phenolic compounds. To identify the causative chemicals for estrogenic activity in the river water of this region, bioassay-directed chemical analysis was performed. All samples from six sampling sites (an upstream point: S1; hot spot points: S2-1, S2-2, and S2-3; and downstream points: S3, and S4) showed estrogenic activity in the E-screen assay, with bio-EEQs (17β-E₂-equivalent quantities) ranging from 25.35-677.15 pg/L. Samples from S2-2, the sampling point downstream of the junction of stream water, and domestic and industrial wastewater, contained the highest estrogenic activity. Since the bio-EEQ of the organic acid fraction (F2) of the S2-2 sample had the highest activity (823.25 pg-EEQ/L) and F2 may contain phenolic compounds, GC-MS analyses for phenolic xenoestrogens were conducted with the organic acid fractions of the river water samples. Six estrogenic phenolic chemicals, 4-NP, BPA, 4-t-OP, 4-t-BP, 4-n-OP, and 4-n-HTP, were detected, with the highest concentrations (I-EEQ) found in S2-2 (231.80 pg/L). Among these phenolic chemicals, 4-NP was the most potent estrogen (bio-EEF; 8.12 × 10^− 5) and acted as a full agonist. Furthermore, 4-NP was present at levels (2.0 µg/L in S2-2) that can induce VTG induction in fish (>1 µg/L). In addition, we confirmed that river water (S2-2) significantly increased serum VTG levels in crucian carp (Carassius auratus) in a fish exposure experiment under laboratory conditions. Therefore, phenolic xenoestrogens, especially 4-NP, may be the main causative compounds responsible for the estrogenic effect on the Nackdong River.     

Characteristics of carbonaceous aerosols in ambient PM10 and PM2.5 particles in Dar es Salaam, Tanzania

Ambient daytime and nighttime PM₁₀ and PM_2.5 samples were collected in parallel at a kerbside in Dar es Salaam in August and September 2005 (dry season) and in April and May 2006 (wet season). All samples were analyzed for the particulate matter mass, for organic, elemental, and total carbon (OC, EC, and TC), and for water-soluble OC (WSOC). The average PM₁₀ and PM_2.5 mass concentrations and associated standard deviations were 76 ± 32 µg/m³ and 26 ± 7 µg/m³ for the 2005 dry season and 52 ± 27 µg/m³ and 19 ± 10 µg/m³ for the 2006 wet season campaign. On average, TC accounted for 29% of the PM₁₀ mass and 49% of the PM_2.5 mass for the 2005 dry season campaign and the corresponding values for the 2006 wet season campaign were 35% and 59%. There was little difference between the two campaigns for the WSOC/OC ratios with the PM_2.5 fraction having higher ratios than the PM₁₀ fraction during each campaign. Also for EC/TC higher ratios were noted in PM_2.5 than in PM₁₀, but the ratios were substantially larger in the 2006 wet season than in the 2005 dry season. The large EC/TC ratios (means 0.22-0.38) reflect the substantial impact from traffic at Dar es Salaam, as was also apparent from the clear diurnal variation in OC levels, with higher values during the day. A simple source apportionment approach was used to apportion the OC to traffic and charcoal burning. On average, 70% of the PM₁₀ OC was attributed to traffic and 30% to charcoal burning in both campaigns. A definite explanation for the substantially larger EC/TC ratios in the 2006 campaign as compared to the 2005 campaign is not available.     

Biodegradation of endocrine disrupting compounds in harbour seawater and sediments

The biodegradation of three endocrine disrupting compounds was examined using samples of seawater and sediment collected from Halifax Harbour, Nova Scotia, Canada, an urbanized harbour impacted by over two centuries of anthropogenic contamination. Flask experiments, where the samples were mixed to form a slurry were used to monitor the aerobic biodegradation of the synthetic plasticizer bisphenol A (BPA), the natural hormone 17β-estradiol (E2), and the pharmaceutical and contraceptive ethinylestradiol (EE2). Degradation rates followed the order E2 > EE2 > BPA with half-lives of up to 1, 5 and 14 days in seawater, respectively. A rapid initial degradation rate for all three compounds with no apparent lag phase indicated the ability of the microbial community to readily catabolise the chemicals. The formation of unidentified non-persistent intermediate metabolites was observed during the E2 degradation experiments. These degradation rates are more rapid and complete than reported in previous studies, indicating the adaptation of native microbial communities to these contaminants.     

Removal of estrogenic activities of 17beta-estradiol and ethinylestradiol by ligninolytic enzymes from white rot fungi

We investigated whether manganese peroxidase (MnP) and the laccase-mediator system with 1-hydroxybenzotriazole (HBT) as mediator can remove the estrogenic activities of the steroidal hormones 17beta-estradiol (E(2)) and ethinylestradiol (EE(2)). Using the yeast two-hybrid assay system, we confirmed that the estrogenic activities of E(2) and EE(2) are much higher than those of bisphenol A and nonylphenol. Greater than 80% of the estrogenic activities of E(2) and EE(2) were removed following 1-h treatment with MnP or the laccase-HBT system; extending the treatment time to 8h removed the remaining estrogenic activity of both steroidal hormones. HPLC analysis demonstrated that E(2) and EE(2) had disappeared almost completely in the reaction mixture after a 1-h treatment. These results strongly suggest that these ligninolytic enzymes are effective in removing the estrogenic activities of E(2) and EE(2).