The Rio Santiago in the Cordillera Negra of Peru is severely contaminated by acid mine drainage in its headwaters. In a strongly acid stream, at about 3800 m above sea level (masl), microterraces were found with terrace walls built up of dead moss, with encrustations and interstitial fine, creamy sediment. The stream water was turbid due to the presence of similar suspended sediment, which also occurred as a thin basal layer in inter-rim basins. The moss was identified as the rare bryophyte Anomobryum prostratum (Müll. Hal.) Besch. Chemical and mineralogical analyses show that green, living parts of the moss are gradually coated by Al/Fe (hydr)oxides, inducing their senescence and death. The necromass is covered by creamy crusts through precipitation of schwertmannite-type material from the stream water and simultaneous ‘capture’ of fine sediment. The latter consists of a mixture of precipitate and fine detrital primary minerals. These processes are held responsible for the formation of the microterraces, which regarding their composition and environment seem to be unique. Remarkable is the high As content of the creamy crusts and sediment, attributed to strong sorption of As, whereas its solute concentration is relatively low. This calls for more attention to suspended fine sediment in the assessment of environmental risks of stream water use. Lastly, the results raise serious doubts about the use of aquatic bryophytes as bioindicator for chemical pollution in acid mine drainage-polluted streams.

Marine birds are important vectors of nutrient and contaminant transfer from sea to land. In eastern Nova Scotia, Canada, colonial marine birds nest on specific nearshore islands within archipelagoes, and we predicted that soils on islands with bird colonies would have higher concentrations of selected trace elements (notably K, Ca, As, Cd, Cu, Pb, Se, Hg, and Zn) than soils on islands without colonies. In this study, common eider (Somateria mollissima), Leach’s storm petrel (Oceanodroma leucorhoa), black guillemot (Cepphus grylle), double-crested cormorant (Phalacrocorax auritus), great black-backed gull (Larus marinus), and herring gull (Larus argentatus) were considered to be the principal avian vectors for contaminant transfer. Results indicate that soils from islands with bird colonies had unique chemical compositions and commonly displayed elevated concentrations of K, Ca, Cu, Se, and Zn when compared to islands without colonies. Thus, marine birds feeding in the nearby marine zone move pollutants and nutrients from the ocean to nesting islands, potentially influencing habitat quality for coastal terrestrial species.

Iodinated contrast media (ICM), which are used for radiological visualization of human tissue and cardiovascular system, are poorly biodegradable; hence, new methods of their removal are sought. In this study, the effectiveness of selected X-ray ICM removal by means of UV and UV/TiO₂pretreatment processes from synthetic hospital wastewater was demonstrated. The following compounds were investigated: iodipamide, iohexol, and diatrizoate. The experiments were as follows: (i) estimated susceptibility of the ICM to decay by UV radiation in different aquatic matrices, (ii) determined an optimal retention time of hospital wastewater in the UV reactor, (iii) determined optimum TiO₂concentration to improve the effectiveness of the UV pretreatment, and (iv) investigated removal of ICM by combination of the photochemical and biological treatment methods. The quantum yields of selected ICM decay in deionized water (pH = 7.0) were established as 0.006, 0.004, and 0.029 for iohexol, diatrizoate, and iodipamide, respectively. Furthermore, the experiments revealed that diatrizoate and iohexol removal in the UV/TiO₂process is more efficient than in UV process alone. For diatrizoate, the removal efficiency equaled to 40 and 30 %, respectively, and for iohexol, the efficiency was 38 and 27 %, respectively. No significant increase in iodipamide removal in UV and UV/TiO₂processes was observed (29 and 28 %, respectively). However, highest removal efficiency was demonstrated in synthetic hospital wastewater with the combined photochemical and biological treatment method. The removal of diatrizoate and iohexol increased to at least 90 %, and for iodipamide, to at least 50 %.

A multivariate analysis was performed in the city of Florence (Italy) to investigate the influence of road traffic and meteorology on air pollution levels at urban traffic stations. Focussing on main traffic-related pollutants (CO, NO, NO₂, NO ₓ and PM₁₀), two typical urban road configurations were analysed: a street canyon and an open road. In addition to traffic flows, basic meteorological parameters were considered: wind speed, air temperature and relative humidity. The influence of all drivers by period of the year and day of the week was analysed with correlation analysis, while a statistical model was developed to predict concentrations at traffic stations by using predictors as urban background concentrations, traffic flows and a site-specific constant. Trained on a 1-year period (2008), the model was validated over an independent 1-year period (2007). The highest correlation of urban traffic concentrations was found vs. background concentrations, markedly for PM₁₀ (r = 0.85–0.87). The influence of road traffic was the highest for NO₂ (r = 0.51–0.58) and the lowest for PM₁₀ (r = 0.36–0.40). Urban-scale poor advection conditions proved to affect PM₁₀ peak levels more significantly than local traffic increase. For all pollutants, good forecasting capability was achieved by the developed statistical model, generally performing better at the street canyon (r = 0.79–0.86) than at the open road (r = 0.72–0.82).

Mosses and lichens are widely used to detect changes in the environmental concentrations of potential contaminants. Several studies have shown the usefulness of transplanted mosses and/or lichens to monitor air depositions of inorganic and organic pollutants at different scales. Here, we present the results of a biomonitoring study carried out in two cities, London (United Kingdom) and Naples (Italy), using four biomonitors (two lichens and two mosses). The lichens, Pseudevernia furfuracea (L.) Zopf var. furfuracea and Parmelia sulcata Taylor, and mosses, Sphagnum capillifolium (Ehrh.) Hedw. and Hypnum cupressiforme Hedw., were exposed in bags in urban streets of Naples and London and in semi-rural and rural areas. Samples were analysed for Cd, Cr, Cu, Fe, Ni, Pb, V and Zn by atomic absorption spectrometry after acid digestion and for 16 EPA polycyclic aromatic hydrocarbons (PAHs) by gas chromatography coupled to mass spectrometry after matrix solid-phase dispersion. For heavy metals, the comparison between the selected mosses indicated that, in all exposure sites, S. capillifolium had a better accumulation performance than H. cupressiforme, whereas for the lichens, it was P. furfuracea which accumulated higher concentrations of metals. Also for total PAHs, S. capillifolium showed a good accumulation capability compared to the other biomonitors investigated, especially compared to H. cupressiforme. It was observed an increasing heavy metal and PAH uptake by biomonitors from rural to urban sites, in both cities.

Genotoxicity of 5-fluorouracil (5-FU), etoposide (ET) and cadmium chloride (CdCl₂) was evaluated in Limnodrilus udekemianus, cosmopolitan tubificid species, by alkaline single-cell gel electrophoresis (comet assay). Groups of 50 individuals were exposed in vivo in water-only short-term (96 h) tests to 5-FU (0.004, 0.04, 0.4, 4 and 40 μM), ET (0.004. 0.04, 0.4 and 4 μM) and CdCl₂ (0.004, 0.04, 0.4, 4 and 40 μM). Mortality of worms was observed only for CdCl₂ (4 and 40 μM). Cell viability lower than 70 % was detected for 5-FU (0.4, 4 and 40 μM), ET (4 μM) and CdCl₂ (0.4 and 4 μM). All tested substances induced significant increase of DNA damage except 0.004 μM of ET. L. udekemianus being sensitive to all tested substances indicates that it can be used in ecogenotoxicology studies. Concern should be raised to cytostatics, especially to 5-FU, since concentration of 0.004 μM induced DNA damage is similar to ones detected in wastewaters.

The aboveground tissue of plants is important for providing roots with constant photosynthetic resources. However, the aboveground biomass is usually harvested before winter to maintain the permanent removal of nutrients. In this work, the effects of harvest on plants’ involvement in oxygen input as well as in microbial abundance and activity were investigated in detail. Three series of constructed wetlands with integrated plants (“unharvested”), harvested plants (“harvested”), and fully cleared plants (“cleared”) were set up. Better performance was found in the unharvested units, with the radial oxygen loss (ROL) rates ranging from 0.05 to 0.59 μmol O₂/h/plant, followed by the harvested units that had relatively lower ROL rates (0.01 to 0.52 μmol O₂/h/plant). The cleared units had the lowest removal efficiency, which had no rhizome resources from the plants. The microbial population and activity were highest in the unharvested units, followed by the harvested and cleared units. Results showed that bacterial abundances and enhanced microbial activity were ten times higher on root surfaces compared with sands. These results indicate that late autumn harvesting of the aboveground biomass exhibited negative effects on plant ROL as well as on the microbial population and activity during the following winter.

The first uranium extraction mine of Brazil, nowadays found in decommissioning phase, has caused several negative environmental impacts in its area, as a result of mining, treatment, and beneficiation processes. The generation of acid mine drainage in waste rock pile 4 (WR-4) is one of the negative impacts with the most critical situation. The acidic water, product of this drainage, presents heavy metals and radioactive elements and it may be infiltrated by the basis of the impoundment basin, where this water is collected for treatment. The objective of this study was to investigate a typical tropical soil, located in the area of Ores Treatment Unit of Caldas in the southwestern state of Minas Gerais, Brazil, in order to use it as a mineral liner for a retention basin to minimize leakage of acidic water through the foundation of a containment dam. In this way, geotechnical, chemical, and mineralogical tests were performed in order to characterize a soil sample collected in the area. In addition, adsorption tests were conducted with solutions of aluminum (Al), manganese (Mn), and iron (Fe), and with and without adjustment of the initial pH (pHₜₒ) of the solutions. The results indicated a well-weathered soil composed of kaolinite, gibbsite, and iron oxides. The adsorption tests showed different behaviors for Al, Mn, and Fe considering or not the adjustment of the pHₜₒ. Aluminum showed low adsorption by soil; because of this, only the adsorption isotherms of Mn and Fe for test with adjustment of the pHₜ₀were determinate. The coefficient of distribution (KD) of Mn was 0.0364 L g⁻¹and Fe 0.0281 L g⁻¹. As for the retardation factor (Rd), its values ranged from 81 to 91 for Mn and from 61 to 79 for Fe, considering different behaviors of the adsorption isotherm models.

At livestock farms, the most important thing is to control odors released from manure. In this study, four commercially available microbial additives designed to control odor and NH₃emissions were applied to swine slurries stored in containers, and their effectiveness in odor reduction was statistically evaluated. Seventeen different odorous compounds in the headspace of each container were analyzed to calculate an overall odor index for slurries treated with different microbial additives over time. Of the four microbial additives tested in this study, only two were effective in reducing the odors from the swine slurry. After a 80-day storage period, the odor indexes of the slurries could be reduced by over 70 % with 50 % reduction in volatile fatty acids. In addition, a significant five orders of magnitude reduction in Escherichia coli could be achieved within 60 days. The other two microbial additives did not affect the odor characteristics of swine slurries under storage; their time profiles were statistically identical with that of the control. Results of this study imply that farmers considering applying microbial additives for controlling odors from swine manure should be careful in choosing an additive.

Panax notoginseng is a well-known phytomedicine used all over the world. In recent years, a certain As contamination of the herb appeared in its planting area due to elevated soil As concentration. We investigated the feasibility of intercropping with Pteris vittata, an As hyperaccumulator, on the reduction of As accumulation in Panax notoginseng and As transfer and transformation in soil-plant system. Results showed that, intercropping could decrease the As concentrations of Panax notoginseng by 9.1–54.3 and 30.9–54.3% and increase the biomasses by 40.7–211.6 and 2.1–153.3 %, respectively, in the H-As (soil As 400.4 mg/kg) and M-As (soil As 85.3 mg/kg) treatments. Compared to the monoculture, the ratio of the nonspecifically adsorbed As in soil was decreased by 17.8 and 34.3 %, and the As transfer factor of Panax notoginseng was increased by 22.2 and 66.3 %, respectively, in H-As and M-As treatments. For As speciation, As(III) and As(V) could be detected at the same time only in root and xylem sap of Panax notoginseng in the H-As treatment, and intercropping could increase the ratios of As(III) by 97.8 and 72.4 %, respectively. In summary, intercropping with Pteris vittata is an applicable approach to reduce the As accumulation in Panax notoginseng.