Estimations of primary and secondary organic carbon formation in PM2.5 aerosols of Santiago City,Chile

High concentration of fine airborne particulates is considered one of the major environmental pollutants in Santiago, the Chilean Capital city, which in 1997 was declared a PM₁₀ saturated zone. To date there is no control of the amounts of fine and coarse aerosols concentrations and the source and chemical characterizations of the PM_2.5 particulates in the carbonaceous fractions are not well known even though this fraction could be represented almost the 50% in mass of the PM_2.5.In this work, we present for the first time determinations of primary organic aerosol (POA) and secondary organic aerosol composition (SOA) fractions of the total mass of PM_2.5 particulates collected in the urban atmosphere of Santiago City. Our purpose is to know the anthropogenic contributions to the formation of SOA. To accomplish this we used the elemental carbon (EC) and organic carbon (OC) determinations developed by automatic monitoring stations installed in the city during the period 2002–2005, with a particular analysis of the summer time occurred in February 2004. Based on the EC tracer method, we have estimated the POA and SOA fraction and our data permit us to estimate the SOA reaching up to 20% of total organic aerosol matter, in good agreement to other measurements observed in large cities of Europe and U.S.A.     

First evidence of polybrominated diphenyl ether (flame retardants) effects in feral barbel from the Ebro River basin (NE, Spain)

Polybrominated diphenyl ethers (PBDEs) are chemicals of environmental concern due to their lipophilic, persistent and bioaccumulable characteristics as well as for their potential endocrine disrupting role. Former studies carried out in a tributary of the Cinca river (Ebro basin, NE Spain) revealed high levels of PBDEs in fish due to the discharges of effluents rich in PBDEs coming from a nearby industrial park in Barbastro. In this study, several biomarkers of pollutants exposure were measured in barbel, Barbus graellsii, before (upstream) and after (downstream) the main industrial site (Barbastro) in the Vero river. The results evidenced an enhanced hepatic phase I and II metabolism (measured as reductases, glutathione S transferase and uridinediphospho-glucuronosyltransferase), and of the antioxidant enzyme glutathione peroxidase. Conversely, fishes collected from downstream reaches had their phase I CYP1A dependent ethoxyresorufin O-deethylase, antioxidant diaphorase and brain cholinesterase activities depleted. In addition, the histological study of the liver and kidney of these fish evidenced an increase of the number and size of macrophage aggregates in most individuals collected downstream. Bivariate correlated analyses showed that the above mentioned biomarkers were correlated to measured PBDE congeners, thus indicating that the observed biological effects were unlikely to be related to other environmental factors than PBDEs. Overall, the measured biochemical and histological markers provide new evidence that in field exposed fish, PBDEs levels were associated with high activities of phase I and II metabolic enzymes, oxidative stress in liver, neurotoxicity in brain and histopathological effects in both liver and kidney.     

Climate change in Mediterranean mountains during the 21st century

Mediterranean mountain biomes are considered endangered due to climate change that affects directly or indirectly different key features (biodiversity, snow cover, glaciers, run-off processes, and water availability). Here, we provide an assessment of temperature, precipitation, and spring precipitation changes in Mediterranean mountains under different emission scenarios (Special Report on Emission Scenarios) and Atmosphere-Ocean-Coupled General Circulation Models for two periods: 2055 (2040-2069 period) and 2085 (2070-2099). Finally, the future climate trends projected for Mediterranean mountains are compared with those trends projected for non-Mediterranean European mountain ranges. The range of projected warming varies between +1.4 degrees C and 5.1 degrees C for 2055 (+1.6 degrees C and +8.3 degrees C for 2085). Climate models also project a reduction of precipitation, mainly during spring (-17% under Alfi and -4.8% under B1 for 2085). On the contrary, non-Mediterranean European mountains will not experience a reduction of annual and spring precipitation. Implications of predicted climate change for both human and physical features are coupled in an integrated framework to gain a broad perspective on future trends and their consequences.     

Compositional analysis of topsoil metals and its associations with cancer mortality using spatial misaligned data

The presence of toxic metals in soil per se, and in soil impacted by mining, industry, agriculture and urbanisation in particular, is a major concern for both human health and ecotoxicology. The dual aim of this study was: to ascertain whether topsoil composition could influence the spatial distribution of mortality due to different types of cancer and to identify possible errors committed by epidemiological studies which analyse soil composition data as a closed number system. We conducted an ecological cancer mortality study, covering 861,440 cancer deaths (27 cancer sites) in 7917 Spanish mainland towns, from 1999 to 2008. Topsoil levels of Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined by ICP-MS at 13,317 sampling points. We transformed the topsoil data in two ways, i.e. log transformation and centred logratio transformation. Principal factor analysis was performed to obtain independent latent factors for the transformed variables. To estimate the effect on mortality of topsoil factor loadings, we fitted Besag, York and Mollié models embedded in geostatistical-spatial models. This model included soil sample locations and town centroids (non-aligned data), fitted using the integrated nested Laplace approximation (INLA) as a tool for Bayesian inference and stochastic partial differential equations (SPDE). All results were adjusted for socio-demographic variables. The results indicated that soil composition could have an influence on the spatial distribution and mortality patterns of cancer. The analysis adjusted for socio-demographic variables showed excess male mortality due to digestive system tumours in areas with soils containing higher Cd, Pb, Zn, Mn and Cu concentrations, bladder cancer in areas with soils containing higher Cd concentrations, and brain cancer in areas with soils containing As. In both sexes, cancer of oesophagus was associated with soils containing a higher lead content, while lung cancer was associated with soils containing a higher copper content. Stress should be laid on the importance of taking into account the compositional nature of the data in this type of analysis.     

Natural concentrations and reference values for trace elements in soils of a tropical volcanic archipelago

Fernando de Noronha is a small volcanic archipelago in the Southern Atlantic, some 350 km NE of the city of Natal in NE Brazil. These remote volcanic islands represent a largely pristine environment, distant from sources of anthropogenic contamination. This study was carried out to determine the natural concentrations of Ag, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, V and Zn in the A and B horizons of soils of Fernando de Noronha. The aims of the study were twofold: determine whether there is a relationship between the bedrock geology and soils and to establish quality reference values for soils from Fernando de Noronha. Soil samples were subjected to acid digestion by the USEPA method 3051A, and metals were determined by inductively coupled plasma emission spectrophotometry. The results showed that the trace element distribution largely reflects the geochemistry of the underlying volcanic rocks of the Remedios and Quixaba Formations. The results demonstrate that the concentrations of Ba, Cr, Zn, Ni and Cu from the soils of the volcanic Fernando de Noronha archipelago are higher than those found in soils from continental Brazil. However, concentrations of Ni, Cu and Co are lower in soils of the archipelago as compared to other volcanic islands throughout the world. The elevated trace element concentrations of the volcanic parent material of Fernando de Noronha soils seem to be the main factor governing the relatively high natural concentrations of trace elements.     

Ontogenetic switch between alternative antipredatory strategies in the leopard gecko (Eublepharis macularius): defensive threat versus escape

Ontogenetic changes in antipredator behavior optimize survival of growing animals. Leopard geckos (Eublepharis macularius) respond to a simulated predator either by postural and vocal threats, sometimes followed by biting, or alternatively by a rapid escape. The former “confrontational” and the latter “avoidance” behavior rarely occurs in a sequence; in fact, they represent mutually exclusive defensive strategies. We examined 552 individuals of a leopard gecko (E. macularius) of various ages, from hatching up to adulthood (31 months). Each experimental animal was exposed to a sequence of five “water-spraying” and ten “stick” (stick poking on base of the tail) stimuli, and the emitted behavior was recorded. We analyzed the effects of age, body size, body condition, adult–juvenile coloration, and sex on observed behavioral traits. The results showed that in the case of water-spraying stimulus, the usage of deterrent vocalization or escape tactic was affected by age and condition. In addition to that, using deterrent vocalization was influenced by the coloration of the animal. Stick stimulus evokes antipredator strategies that correspond with age and coloration (deterrent vocalization) and also with standardized body size (escape). Thus, leopard geckos exhibit clear ontogenetic change of defensive strategies, from threat–vocalization–bite strategy prevailing in juveniles to an escape strategy typical for adults. This behavioral change is accompanied by the ontogenetic switch of coloration from presumably warning contrasting light–dark banded pattern of juveniles to a cryptic spotted coloration of the adults.     

Pine needles as passive bio-samplers to determine polybrominated diphenyl ethers

Eight polybrominated diphenyl ethers (PBDEs) were determined in pine needles of three species (Pinus halepensis, Pinus pinea and Pinus nigra) collected in the NE Spain in an attempt to use this matrix for the biomonitoring of airborne PBDEs. The method used was based in ultrasonic extraction followed by alumina and Florisil clean-up and determination by gas chromatography coupled to mass spectrometry in negative chemical ionization. Recoveries were between 99% and 138%, limits of detection between 0.011 and 0.070 ng g⁻¹-dw (0.232 ng g⁻¹-dw for BDE 209) and repeatability lower than 13%. PBDE levels ranged between 0.027 ng g⁻¹-dw and 13.04 ng g⁻¹-dw, with predominance of BDE 209, followed by BDEs 47. P. halepensis was the species with the highest PBDE levels and P. nigra, the least, according to their widespread and remote distribution, respectively. The presence of PBDEs in pine needles was attributed to the release of in-use PBDEs, transport through atmosphere and adsorption upon lipid rich pine needles. Given the easy collection of pine needles, its ample distribution and its potential to accumulate airborne contaminants, this matrix is proposed as passive bio-sampler to be used in PBDE monitoring programs.

Capsule

Pine needles can be used to biomonitor airborne PBDEs.     

Biochemical and locomotor responses of Carcinus maenas exposed to the serotonin reuptake inhibitor fluoxetine

The aim of this study was to assess the effects of the widely used anti-depressant fluoxetine on behaviour (locomotion), moulting, neuromuscular transmission, energy production and anti-oxidant defences’ efficiency of the epibenthic crab Carcinus maenas. Crabs were individually exposed to fluoxetine concentrations for 7 d. Effects on locomotion were assessed at the end of the exposure using an open field test adapted to C. maenas in the present study. Tissue samples were later collected to evaluate fluoxetine effects on physiological functions using the activity of key enzymes and other parameters as biomarkers, namely: N-acetyl-β-glucosaminidase (NAGase) in the epidermis (moulting) and the hepatopancreas; cholinesterases (ChE) in muscle (neuromuscular cholinergic transmission); NADP⁺-dependent isocitrate dehydrogenase (IDH) and lactate dehydrogenease (LDH) in muscle (energy production); glutathione S-transferases (GST) in hepatopancreas (biotransformation and oxidative stress system); glutathione reductase (GR), and glutathione peroxidade (GPx), total glutathione levels (TG) and lipid peroxidation levels in the hepatopancreas (anti-oxidant defences and oxidative damage). Because no information on C. maenas NAGase activity was previously available, its variation during the moult cycle was also investigated. The results showed that locomotion was significantly increased at fluoxetine concentrations equal or above 120 μg L⁻¹, with animals spending more time moving, walking longer distances than controls. Levels of NAGase activity were found to vary in relation to C. maenas moult cycle, but no alterations were observed after exposure to fluoxetine. Significant increases in the activity of ChE, GST and GR enzymes, and the levels of TG were found, with a lowest observed effect concentration (LOEC) of 120 μg L⁻¹. Effects on locomotion were significantly and positively correlated to those induced on ChE activity. The results raise concern when hypothesising conditions of chronic exposure in the wild.