In mussels, stress signals such as heat, osmotic shock and hypoxia lead to the activation of the phosphorylated p38 mitogen activated protein kinase (pp38-MAPK). This stress activated protein has been efficiently used as a biomarker to several natural and anthropogenic stresses. However, what has not been tested is whether differences in gender or size can affect the response of this biomarker. The present study tested whether there was variation in the expression of pp38-MAPK in mussels Perna perna of different gender and size classes when exposed to natural stress conditions, such as air exposure. The results show that gender does not affect the expression of pp38-MAPK. However, size does have an effect, where mussels smaller than 6.5 cm displayed significantly (p < 0.05) lower levels of pp38-MAPK when compared to those larger than 7 cm. Mussels are one of the most used bioindicator species and the use of biomarkers to determine the health status of an ecosystem has been greatly increasing over the years. The present study highlights the importance of using mussels of similar size classes when performing experiments using stress-related biomarkers.

This paper is a review of the available literature on the main features of 11 of the most widely adopted oxygenated additives to base gasoline and diesel, focusing particularly on the emissions from the oxygenates considered as additives. The oxygenated additives studied are methyl tert-butyl ether, ethyl tertiary butyl ether, tert-amyl ethyl ether, tertiary amyl methyl ether, isopropyl ether, dimethyl carbonate, dimethoxymethane, dibutyl ether, diglycol methyl ether, diethyl carbonate, and 2-methoxyethyl acetate.

The current study aimed to compare lindane degradation by pure and mixed cultures of Streptomyces sp. Cell-free extracts were assayed for potentiating dechlorinase activity and, based on these results, consortia of two to six microorganisms were assayed for their growth on and degradation of lindane. Furthermore, the role of bacterial consortia of lindane-degrading strains was examined in lindane decontamination soil assays. Four actinobacteria, previously isolated from a pesticide-contaminated area, were selected because of their tolerance to lindane and their ability to use the pesticide as sole carbon source. These strains as well as Streptomyces sp. M7 and Streptomyces coelicolor A3 were used to study specific dechlorinase activity (SDA) and lindane removal in mixed cultures. Pure cultures presented SDA in the presence of 1.66 mg L-1 lindane as carbon source. SDA was improved by certain mixed cultures until 12 times compared with pure cultures. Mixed cultures with two, three, and four strains showed maximum lindane removal of 46% to 68%, whereas combinations of five and six strains did not efficiently remove the pesticide from the culture medium. The Streptomyces sp. A2, A5, M7, and A11 consortium presented the lowest ratio between residual lindane concentration and SDA and could be a promising tool for lindane biodegradation.

This study investigated the effects of age and length on mercury contamination in four fish species; yellow-eye mullet (Aldrichetta forsteri), black bream (Acanthopagrus butcheri), sand flathead (Platycephalus bassensis) and sea-run brown trout (Salmo trutta) from the Derwent Estuary, Tasmania, Australia, and examined the implications of these findings for public health monitoring. Mean mercury levels exceeded the Food Standards Australia and New Zealand maximum permitted level (0.5 mg kg⁻¹) for all species except yellow-eye mullet. Mean levels in black bream were significantly higher (p < 0.05) than other species and consequently are a particular concern for human health. Regional differences (p < 0.05) in mercury levels in sand flathead were not obviously correlated with metal levels in the sediments. However, age and length significantly (p < 0.05) influenced mercury levels in brown trout and sand flathead, with age being more strongly related to intraspecies differences. In addition, movement and distribution within the estuary and trophic status appeared to be important factors in contribution to interspecific variation. Consequently, a sound understanding of fish life history and biology is important in identifying species which may be susceptible to accumulating mercury and hence pose a potential threat to human health.

Due to increased whole-tree harvesting in Swedish forestry, concern has been raised that a depletion of nutrients in forest soil will arise. The Swedish Forest Agency recommends compensation fertilization with wood ash to ensure that unwanted effects are avoided in the nutrient balance of the forest soil and in the quality of surface water. In this investigation, the chemistry of two first-order streams, of which one was subjected to a catchment scale treatment with 3 tonnes of self-hardened wood ash/ha in the fall of 2004, was monitored during 2003–2006. Large seasonal variations in stream water chemistry made changes due to ash application difficult to detect, but evaluating the ash treatment effects through comparison of the stream water of the treated catchment with the reference was possible via statistical tools such as randomized intervention analysis in combination with cumulative sum charts. The wood ash application did not yield any significant effect on the pH in the stream water and hence did not affect the bicarbonate system. However, dissolved organic carbon increased, a previously unreported effect of WAA, bringing about an increase of organic anions in the stream water. The wood ash application also induced significant increases for Ca, Mg, K, Si, Cl and malonate, of which K was most prominent. Although significant, the changes induced by the wood ash application were all small compared to the seasonal variations. As a tool to counteract acidification of surface waters, WAA seems to have limited initial effects.

This paper reviews the interrelationship among boundary layer, urbanization, and evolution of ozone, with particular emphasis on how boundary layer dynamics and urbanization affects the evolution of ozone under different meteorological and climatological conditions. The aim of this work is not only to provide an exhaustive investigation of individual ozone episodes but to look at the underlying issues and hypotheses that are available for understanding the evolution of ozone. The review concludes with a summary of the current state of knowledge and outlines some of the remaining questions. It is the intention of this paper to serve as an ecumenical reference to the community for reappraising the relation of boundary layer climate to the evolution of ozone in an urban setting, especially on a peculiar feature of ozone dynamic, nocturnal ozone maxima. To date, there is still no overarching consensus on the mechanisms that lead to its formation. The importance of levels of urbanization and advantage of ascertaining the substantial weights of the respective mixing height and emission structure in exploring the relationship between ozone evolutions should not be overlooked.

The disruption of endocrine systems due to environmental contaminants potentially impacts on the developmental, behavioural, regulatory and reproductive systems of animals. A major source of exposure of animals (terrestrial and aquatic) to endocrine-disrupting compounds is through contact with contaminated surface waters contaminated with sewage effluent and/or stormwater discharge. We studied the response to endocrine-disrupting compounds of Gambusia holbrooki mosquito fish resident of wetlands that were used for the storage of either treated sewage effluent or stormwater runoff. We found that fish from wetlands that received polluted waters directly from the source (treated sewage effluent or stormwater runoff) demonstrated a morphological response consistent with endocrine disruption. In contrast, fish in the second in the series of wetlands that housed treated sewage effluent did not show evidence of such response. However, those from the second in the series of stormwater receiving wetlands did display a morphological response, although it could be considered milder than was observed in fish from the first in this effluent stream. Fish were also smaller in the wetland that received sewage effluent directly from the sewage treatment plant than elsewhere. Although the differences were not statistically significant, the average size of fish in the first in the series of stormwater wetlands were also small and second only to those in the first sewage effluent wetland.

This study applied the Model of Acidification of Groundwater in Catchments (MAGIC) to estimate the sensitivity of 66 watersheds in the Southern Blue Ridge Province of the Southern Appalachian Mountains, United States, to changes in atmospheric sulfur (S) deposition. MAGIC predicted that stream acid neutralizing capacity (ANC) values were above 20 μeq/L in all modeled watersheds in 1860. Hindcast simulations suggested that the median historical acidification of the modeled streams was a loss of about 25 μeq/L of ANC between 1860 and 2005. Although the model projected substantial changes in soil and stream chemistry since pre-industrial times, simulated future changes in response to emission controls were small. Results suggested that modeled watersheds would not change to a large degree with respect to stream ANC or soil % base saturation over the next century in response to a rather large decrease in atmospheric S deposition. Nevertheless, the magnitude of the relatively small simulated future changes in stream and soil chemistry depended on the extent to which S emissions are reduced. This projection of minimal recovery in response to large future S emissions reductions is important for designing appropriate management strategies for acid-impacted water and soil resources. Exploratory analyses were conducted to put some of the major modeling uncertainties into perspective.

The presence of endocrine-disrupting chemicals (EDCs) in wastewater effluent is a major concern to the scientific community. This research effort was aimed at investigating Fenton-like degradation of two EDCs 17β-estradiol (E2) and 17α-ethinylestradiol (EE2). The results of the study showed that E2 and EE2 were effectively removed by the Fenton-like oxidation process. Removal efficiencies of 95% and 98% at ferric concentration of 1 × 10−3 M (58.6 mg l−1) were achieved for E2 and EE2, respectively. The kinetics of Fenton-like degradation of E2 and EE2 were adequately described by the pseudo second order kinetic model. Values of 27.8 and 22.5 kJ mol−1 were obtained for the activation energy for E2 and EE2, respectively, from the Arrhenius-type plot, showing that the process does not just involve radical reactions but also intermediate reaction steps involving radical–molecule or ion–molecule reactions. The presence of high dissolved organics in wastewater significantly reduced the removal efficiencies. The reaction by-products for E2 and EE2 were more stable to the oxidation process and more readily biodegradable. Fenton-like oxidations therefore offers a promising alternative for the removal of these EDCs in wastewater treatment applications at the tertiary treatment stage.

Concentrations of heavy metals in the western coast of Venezuela are partly driven by anthropogenic influences. To detect metal changes over time, the waters and sediments from 19 sites, across various marine ecosystems, were sampled seven times between 2000 and 2001 and compared with previous studies. The water samples had mean concentrations of Cd, Cu, Pb, and Zn above the guideline values proposed by NOAA as capable of producing chronic effects in the marine biota. In sediments, the mean Cd concentration also exceeded NOAA's Effects Range-Low values for all habitat types, and in sheltered sites, it exceeded NOAA's Effects Range-Median values. The meta-analysis indicated that metal concentrations in water were higher in 2000-2001 than in 1995-1997, with the exception of Pb. In sediments, however, only the concentrations of Cd, Cu, and Pb increased in this period. This increase was particularly noticeable for Cd which, by 2000-2001, showed Igeo values indicating that Morrocoy National Park could be considered strongly to extremely polluted. This increment in the metal concentrations could be associated with: (1) an anomalous precipitation event that occurred at the end of 1999 and which caused a disturbance in the sediment chemistry of most metals and/or (2) an increase in the anthropogenic and natural input of Cd probably associated with the production of fertilizers in the region during the period analyzed. Special attention should be paid to Cd levels in this area as it represents a high toxicological risk for the biota in different habitats.