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Recent studies in the Douro River estuary show signs of pollution in the area and of fish endocrine disruption. However, the chemical nature of the local contamination has not been fully investigated nor have studies checking for the simultaneous presence of endocrine-disrupting chemicals (EDCs), either of animal (estrone, E1; estradiol, E2), pharmaceutical (17alpha-ethynylestradiol, EE2), vegetal (daidzein, DAID; genistein, GEN; biochanin A, BIO-A), or industrial (bisphenol A, BPA; 4-octylphenol, 4-OP; 4-nonylphenol, 4-NP) origins. Thus, the main objective of this study was to examine the presence of these EDCs in estuarine water samples collected, in every season of the year, at nine sampling stations along the estuarine gradient. All samples were processed by two-step solid-phase extraction (Oasis HLB followed by silica) prior to high-performance liquid chromatography with diode-array detection (HPLC-DAD) and gas chromatography-mass spectrometry (GC-MS) analyses. The current data showed that E1 and EE2, all phytoestrogens, and BPA were identified and measured in this estuary. In contrast, 4-OP was only detected by GC-MS and E2 and 4-NP were not found. Additionally, E1 (up to 112.9 ng/L) and EE2 (up to 101.9 ng/L) were both measured in biologically hazardous amounts in winter. In the year sampled, the phytoestrogens suggested a possible seasonal pattern of fluctuation. Both DAID (up to 888.4 ng/L) and GEN (183.6 ng/L) were maximal in early summer, whereas BIO-A (up to 191.4 ng/L) reached its highest concentrations in winter. BPA (up to 10.7 microg/L) also attained highest levels in winter. In December 2005, it is hypothesized that E1, EE2, and BPA concentrations were atypically high due to current drought conditions. Almost all assayed EDCs existed in all seasons and, therefore, might have contributed to endocrine disruption of aquatic animals, previously documented by the high rate of ovotestis in fish caught in this estuary.

A gas chromatography with mass spectrometric detection (GC-MS) method was developed and optimized for the determination of 17 endocrine disrupting compounds (EDCs) in coastal water samples. The evaluated EDCs were from different origins and included estrogens, bisphenol A, alkylphenolethoxylates, alkylphenols, phytoestrogens and sitosterol (SITO). The EDCs were extracted from samples using Oasis HLB (Hydrophilic-Lipophilic Balance) cartridges and derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) added with 1% trimethylchlorosilane (TMCS). The validation parameters revealed that this method was highly specific for all assayed compounds (>99%) and the linearity of the calibration curves showed a correlation higher than 0.99. The detection limits were at low ng/L level and the recovery rates were higher than 70%. The performance of the method was checked using coastal water samples taken every 2 months during 2009-2010 from the Douro River estuary and the Porto coastline (Portugal). These data revealed that approximately 98.0% of the analyzed compounds showed levels above their limits of detection (LODs). The measured estrogens (2-20 ng/L) and industrial pollutants (up to 1.1 μg/L) were in biologic hazardous concentrations. Besides, a clear seasonal pattern of fluctuation was established for phytoestrogens and SITO. The physicochemical data, namely the amounts of nitrates, nitrites and phosphorous, confirmed the low water quality of this area.

This paper describes the development and validation of a simple analytical method using solid-phase extraction followed by a high-performance liquid chromatography with diode array detection (HPLC-DAD) analysis. Target compounds included six pharmaceuticals (carbamazepine, diazepam, fluoxetine, propranolol, sulfamethoxazole, and trimethoprim) and the active metabolite of fenofibrate (fenofibric acid). Briefly, this method consisted of the preconcentration of water samples (2 L) on 500 mg Oasis HLB cartridges and HPLC analysis using a RP-(18) analytical column in a gradient mode with a flow rate of 1 mL/min. The validation parameters revealed that this method was highly specific for all assayed compounds (> 99%), and the linearity of the calibration curves always showed a correlation higher than 0.99. The detection limits were in the ng/L level, and recovery rates were > 70% for most of the target compounds. Analysis of samples from polluted areas of the Douro River estuary indicated that propranolol and carbamazepine are present in concentrations ranging from 22.0 to 54.0 ng/L and 21.3 to 32.7 ng/L, respectively. Thus, it is concluded that this method can be successfully applied for screening pharmaceuticals in polluted estuarine areas.

Changes in fish macrophages (Macs) are useful indicators of environmental pressures, but responses due to chemical and nonchemical stresses may be confounded by natural sources of variability. These may include sex and gonadal stage. In this study, we start addressing the following question: is the seasonally dependent ovary stage a factor to consider when using kidney Macs as biomarkers? To tackle this problem, the relative amount of pigmented Macs in kidney (head, trunk, and tail portions) was stereologically estimated in Ohrid trout, and related with the breeding status. The amount of Macs significantly increased from pre vitellogenesis to late vitellogenesis and showed a decreasing trend then after, with lower values noted after spawning in the head (1.9% versus 7.5% versus 2.0%), trunk (1.8% versus 7.5% versus 2.5%), and tail (2.5% versus 6.7% versus 2.9%) kidney. The decrease seen at spawning was significant in head and trunk kidney, and at post spawning it was significant for all kidney portions. The amounts of Macs were positively correlated with the ovary relative weights and plasma estradiol levels. We proved for the first time that fish kidney pigmented Macs can vary in amount during the breeding cycle. Our data, combined with literature, strongly support that the sex-steroid profile and kidney status-seasonal remodeling both influence the Macs pool; likely not only in female trout. So, while increases in Macs may warn of ecosystem problems, we show that using kidney Macs for biomonitoring should also take into account seasonally, particularly that related with ovary maturation.

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