Clotrimazole is an azole fungicide used as a human pharmaceutical that is known to inhibit cytochrome P450 (CYP) enzymatic activities, including several steroidogenic CYP. In a previous report, we showed that a 7-day exposure to clotrimazole induced the expression of genes related to steroidogenesis in the testes as a compensatory response, involving the activation of the Fsh/Fshr pathway. In this context, the aim of the present study was to assess the effect of an in vivo 21-day chronic exposure to clotrimazole (30–197 μg/L) on zebrafish testis function, i.e., spermatogenesis and androgen release. The experimental design combined (1) gene transcript levels measurements along the brain–pituitary–gonad axis, (2) 11-ketotestosterone (11-KT) quantification in the blood, and (3) histology of the testes, including morphometric analysis. The chronic exposure led to an induction of steroidogenesis-related genes and fshr in the testes as well as fshβ in the pituitary. Moreover, increases of the gonadosomatic index and of the volume proportion of interstitial Leydig cells were observed in clotrimazole-exposed fish. In accordance with these histological observations, the circulating concentration of 11-KT had increased. Morphometric analysis of the testes did not show an effect of clotrimazole on meiotic (spermatocytes) or postmeiotic (spermatids and spermatozoa) stages, but we observed an increase in the number of type A spermatogonia, in agreement with an increase in mRNA levels of piwil1, a specific molecular marker of type A spermatogonia. Our study demonstrated that clotrimazole is able to affect testicular physiology and raised further concern about the impact of clotrimazole on reproduction.

The concentrations, compositional profiles, and possible sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) in water column and surface sediment samples from the lower reaches of the Yangtze River were investigated, and the potential risks posed by these chemicals were evaluated. Concentrations of the 17 2,3,7,8-substituted PCDD/PCDF in the water and sediment samples ranged from 0.45 to 10.0 pg TEQ/L (mean 2.34 pg TEQ/L) and from 0.31 to 51 pg TEQ/g dw (mean 5.25 pg TEQ/g dw), respectively. Water and sediments from the Nanjing-Nantong sections of the Yangtze River were found to have elevated PCDD/PCDF levels, and the PCDD/PCDF TEQ concentrations in 13 sediment samples exceeded the probable effect levels (PEL), above which adverse biological effects are likely. Multivariate statistical analysis indicated that the principal PCDD/PCDF contamination source for the water and sediment was the production and use of pentachlorophenol (PCP) or sodium pentachlorophenate (PCP-Na). PCDD/PCDF concentrations were stable over time near the Yangtze River Estuary but had increased sharply in recent decades in the Nanjing-Nantong section, which will have been related to the growth in industrial activities and other anthropogenic PCDD/PCDF sources. Total organic carbon (TOC) and PCDD/PCDF concentrations correlated significantly (R = 0.474, P < 0.01), suggesting that TOC plays an important role in the transport and re-distribution of PCDD/PCDF in the Yangtze River basin.

The construction and electrodes characteristics of poly(vinylchloride) (PVC)-based polymeric membrane electrode (PME) and coated graphite electrode (CGE), incorporating 1,3-alternate thiacalix[4]crown as ionophore for estimation of Hg(II) ions, are reported here. The best potential response was observed for PME-1 having membrane composition of: ionophore (6.2 mg), PVC (100.0 mg), 2-nitrophenyl octyl ether (2-NPOE; 200.0 mg), and sodium tetraphenyl borate (NaTPB; 2.0 mg); for CGE-1 with the membrane composition: ionophore (3.5 mg), PVC (40.0 mg), 2-NPOE (80.0 mg), and NaTPB (2.0 mg). The electrodes exhibits Nernstian slope of 29.16 mV/decade with PME-1 and 30.39 mV/decade with CGE-1 for Hg(II) ions over wide concentration range, i.e., 1.0 × 10⁻¹ to 5.0 × 10⁻⁶ M with PME-1 and 1.0 × 10⁻¹ to 5.0 × 10⁻⁷ M with CGE-1. Lower detection limits were found to be 9.77 × 10⁻⁶ M for PME-1 and 7.76 × 10⁻⁷ M for CGE-1 with response time varying from 10 to 20 s. Also, these electrodes work within pH range of 2.0–6.0 for PME-1 and 1.5–6.5 for CGE-1. Overall, CGE-1 has been found to be better than PME-1. CGE-1 has been used as indicator electrode for the potentiometric titration of Hg(II) ions with EDTA as well as successfully applied for determination of Hg(II) content in wastewater, insecticide, dental amalgam, and ayurvedic medicines samples with very good performance (0.9974 correlation coefficient in the comparison against volumetric method).

The abandoned Pb-As Baccu Locci mine represents the first and only case of mine site remediation in Sardinia, Italy. Arsenic is the most relevant environmental concern in the Baccu Locci stream watershed, with concentrations in surface waters up to and sometimes over 1 mg/L. The main remediation action consisted in creation of a "storage site", for the collection of contaminated materials from different waste-rock dumps and most of tailings piles occurring along the Baccu Locci stream. This paper reports preliminary results on the level of contamination in the Baccu Locci stream after the completion of remediation measures. Post-remediation stream water chemistry has not substantially changed compared to the pre-remediation situation. In particular, dissolved As maintains an increasing trend along the Baccu Locci stream, with a concentration of about 400 μg/L measured at a distance of 7 km from the storage site. Future monitoring will provide fundamental information on the effectiveness of remediation actions conducted and their applicability to other mine sites in Sardinia. At the stage of mine site characterisation of future remediation plans, it is recommended to pay more attention to the understanding of mineralogical and geochemical processes responsible for pollution. Moreover, mixing of materials with different composition and reactivity in a storage site should require careful consideration and long-term leaching tests.

A total of 112 surface sediment samples covering virtually the entire Bohai Sea were analyzed for polycyclic aromatic hydrocarbons (PAHs), in order to provide the extensive information of recent occurrence levels, distribution, possible sources, and potential biological risk of these compounds in this area. Surface sediment samples were collected from the Bohai Sea using a stainless steel grab sampler. Sixteen PAHs were determined by a Finnigan TRACE DSQ gas chromatography/mass spectrometry. Diagnostic ratios, cluster analysis, and principal component analysis (PCA) with multivariate linear regression (MLR) were performed to identify and quantitatively apportion the major sources of sedimentary PAHs in the Bohai Sea. Concentrations of total PAHs in the Bohai Sea ranged widely from 97.2 to 300.7 ng/g (mean, 175.7 ± 37.3 ng/g). High concentrations of PAHs were found in the vicinity of Luan River Estuary-Qinhuangdao Harbor, Cao River Estuary-Bohai Sea Center, and north of the Yellow River Estuary. The three-ring PAHs were most abundant, accounting for about 37 ± 5 % of total PAHs. The four-ring and five-ring PAHs were the next dominant ones comprising approximately 29 ± 7and 23 ± 3 % of total PAHs, respectively. Concentrations of acenaphthylene, acenaphthene, and dibenz[a,h]anthracene are higher than Canadian interim marine sediment quality guideline values at most of the sites in the study area. Contamination levels of PAHs in the Bohai Sea were low in comparison with other coastal sediments in China and developed countries. The distribution pattern of PAHs and source identification implied that PAH contamination in the Bohai Sea mainly originates from petrogenic and pyrogenic sources. Further PCA/MLR analysis suggested that the contributions of spilled oil products (petrogenic), coal combustion, and traffic-related pollution were 39, 38, and 23 %, respectively. Pyrogenic sources (coal combustion and traffic-related pollution) contributed 61 % of anthropogenic PAHs to sediments, which indicates that energy consumption could be a dominant factor in PAH pollution in this area. Acenaphthylene, acenaphthene, and dibenz[a,h]anthracene are the three main species of PAHs with more ecotoxicological concern in the Bohai Sea.

The removal of estrogenic chemicals during wastewater reclamation has been a great concern. Current advanced treatment processes are inefficient for the removal of estrogenic chemicals from secondary effluents of municipal wastewater treatment plants (WWTPs) due to the coexistence of other pollutants with less environmental significance which are also removed simultaneously. The search for highly selective and low-cost removal methods is warranted. Therefore, surface-molecular-imprinted polymer-modified TiO₂ nanotube (S-MIP-TiO₂ NT) photocatalysts were fabricated, characterized, and tested for the removal of estrogenic pollutants from wastewater in this study for the first time. Scanning electron microscopy and Fourier-transform infrared spectroscopy studies showed that the TiO₂ NTs (with an average diameter of 60 nm) were successfully imprinted with functional groups (i.e., carboxyl). The adsorption selectivity and photocatalytic activity of the S-MIP-TiO₂ NTs towards template compound (17β-estradiol, E2) were improved, compared with neat TiO₂ NTs. Interestingly, S-MIP-TiO₂ NTs exhibited higher adsorption intensity and photocatalytic selectivity at low concentrations (from 10 ng/L to 100 μg/L, as normal estrogenic chemical concentrations in secondary effluents) of E2 than that at high concentrations (from 10 to 1,000 mg/L). It was also found that some representative estrogenic chemicals and estrogenic activity could be selectively and rapidly removed from secondary effluents of municipal wastewater treatment plants using S-MIP-TiO₂ NTs as photocatalysts. In addition, S-MIP-TiO₂ NT photocatalysts exhibited excellent regeneration characteristics. Photocatalytic treatment using S-MIP-TiO₂ NTs could be a promising approach for the effective removal of estrogenic chemicals from secondary effluents of municipal WWTPs.

The object of this study was to assess the capacity of Populus alba L. var. pyramidalis Bunge for phytoremediation of heavy metals on calcareous soils contaminated with multiple metals. In a pot culture experiment, a multi-metal-contaminated calcareous soil was mixed at different ratios with an uncontaminated, but otherwise similar soil, to establish a gradient of soil metal contamination levels. In a field experiment, poplars with different stand ages (3, 5, and 7 years) were sampled randomly in a wastewater-irrigated field. The concentrations of cadmium (Cd), Cu, lead (Pb), and zinc (Zn) in the poplar tissues and soil were determined. The accumulation of Cd and Zn was greatest in the leaves of P. pyramidalis, while Cu and Pb mainly accumulated in the roots. In the pot experiment, the highest tissue concentrations of Cd (40.76 mg kg(-1)), Cu (8.21 mg kg(-1)), Pb (41.62 mg kg(-1)), and Zn (696 mg kg(-1)) were all noted in the multi-metal-contaminated soil. Although extremely high levels of Cd and Zn accumulated in the leaves, phytoextraction using P. pyramidalis may take at least 24 and 16 years for Cd and Zn, respectively. The foliar concentrations of Cu and Pb were always within the normal ranges and were never higher than 8 and 5 mg kg(-1), respectively. The field experiment also revealed that the concentrations of all four metals in the bark were significantly higher than that in the wood. In addition, the tissue metal concentrations, together with the NH4NO3-extractable concentrations of metals in the root zone, decreased as the stand age increased. P. pyramidalis is suitable for phytostabilization of calcareous soils contaminated with multiple metals, but collection of the litter fall would be necessary due to the relatively high foliar concentrations of Cd and Zn.

The effective disposal of redundant elephant dung (ED) is important for environmental protection and utilization of resource. The aim of this study was to remove a toxic-azo dye, Reactive Red (RR) 120, using this relatively cheap material as a new adsorbent. The FTIR-ATR spectra of ED powders before and after the sorption of RR 120 and zero point charge (pHzpc) of ED were determined. The sorption capacity of ED for removing of RR 120 were carried out as functions of particle size, adsorbent dose, pH, temperature, ionic strength, initial dye concentration, and contact time. Sorption isotherm, kinetic, activation energy, thermodynamic, and desorption parameters of RR 120 on ED were studied. The sorption process was found to be dependent on particle size, adsorbent dose, pH, temperature, ionic strength, initial dye concentration, and contact time. FTIR-ATR spectroscopy indicated that amine and amide groups have significant role on the sorption of RR 120 on ED. The pHzpc of ED was found to be 7.3. Sorption kinetic of RR 120 on ED was well described by sigmoidal Logistic model. The Langmuir isotherm was well fitted to the equilibrium data. The maximum sorption capacity was 95.71 mg g(-1). The sorption of RR 120 on ED was mainly physical and exothermic according to results of D-R isotherm, Arrhenius equation, thermodynamic, and desorption studies. The thermodynamic parameters showed that this process was feasible and spontaneous. This study showed that ED as a low-cost adsorbent had a great potential for the removal of RR 120 as an alternative eco-friendly process.

We evaluated 41 rural workers occupationally exposed to pesticides and 32 subjects as a control group, using the micronucleus (MN) and the comet assay. For the comet assay, we evaluated the peripheral blood, and for the MN, we sampled cells from the oral epithelium. Damage to DNA was measured by tail length, % DNA in tail (% tail), olive tail moment (OTM), and tail moment (TM). The exposed group presented an 8× increase in MN frequency, when compared to the control group (p <0.05). When we contrasted the MN frequencies between the individuals that use and do not use personal protective equipment, we found a mean of 7.5 MN (57 % variance) and 12.1 MN (130 % variance), respectively. The binucleated cells were 0.04 and 0.005, in the exposed and control groups, respectively, indicating 8× increase in the number of binucleated cells, when comparing the groups (p <0.05). In the comet assay, we demonstrated statistically significant differences in three parameters (% DNA, OTM, and TM) indicating that the rural workers presented high levels of genomic damages. Our results indicate that occupational exposure to pesticides could cause genome damage in somatic cells, representing a potential health risk to Brazilian rural workers that deal constantly with agrochemicals without adequate personal protection equipment.

Nitrogen removal processing in different constructed wetlands treating different kinds of wastewater often varies, and the contribution to nitrogen removal by various pathways remains unclear. In this study, the seasonal nitrogen removal and transformations as well as nitrogen balance in wetland microcosms treating slightly polluted river water was investigated. The results showed that the average total nitrogen removal rates varied in different seasons. According to the mass balance approach, plant uptake removed 8.4–34.3 % of the total nitrogen input, while sediment storage and N₂O emission contributed 20.5–34.4 % and 0.6–1.9 % of nitrogen removal, respectively. However, the percentage of other nitrogen loss such as N₂ emission due to nitrification and denitrification was estimated to be 2.0–23.5 %. The results indicated that plant uptake and sediment storage were the key factors limiting nitrogen removal besides microbial processes in surface constructed wetland for treating slightly polluted river water.