Mass scans from a proton transfer mass spectrometry analysis of air over Mediterranean shrubland browsed by horses

Plants usually emit large amount and varieties of volatiles after being damaged by herbivores. However, analytical methods for measuring herbivore-induced volatiles do not normally monitor the whole range of volatiles and the response to large herbivores such as large mammals is much less studied than the response to other herbivores such as insects. In this paper we present the results of using a highly sensitive proton transfer reaction-mass spectrometry (PTR-MS) technique that allows simultaneous monitoring of leaf volatiles in the pptv range. The resulting mass scans in air over Mediterranean shrubland browsed by horses show 70 to 100% higher concentrations of the masses corresponding to mass fragments 57, 43 and 41 (mostly hexenals, acetone and acetic acid) than scans over control non-browsed shrubland. These compounds are biogeochemically active and they are significant components of the volatile organic carbon found in the atmosphere. They influence the performance of living organisms and, the chemical and physical processes of Earth's atmosphere.     

Saharan dust episodes and pregnancy

Desert dust is one of the natural contributors to atmospheric particulate matter worldwide. Although particulate pollution has been shown to adversely affect pregnancy, the available evidence on the impact of dust episodes on pregnancy is very scarce. The aim of this study was to evaluate the impact of Saharan dust episodes on pregnancy complications (preeclampsia and bacteriuria) and outcomes (birth weight and gestational age at delivery). This study was based on a cohort of births (N = 3565) that occurred in a major university hospital in Barcelona during 2003-2005. To determine Saharan dust episodes, we developed a two-stage approach based on meteorological evidence of the presence of Saharan dust cloud over the region and unusually high levels of particulate levels on the ground while taking account of traffic sources. The associations between the number of Saharan dust episodes during whole pregnancy as well as each pregnancy trimester and pregnancy complications and outcomes were analysed. There were 152 days (out of 838 days) with Saharan dust cloud over the region from which 45 days were determined as episodic days. We did not observe any statistically significant harmful effect of Saharan dust episodes on our included pregnancy complications and outcomes. However, we observed a small but statistically significant increase in gestational age at delivery in association with the number of episodic days during the third trimester and whole pregnancy (0.8 and 0.5 days respectively). Our findings were not suggestive for any adverse effect of Saharan dust episodes on our included pregnancy complications and outcomes.     

A spatially explicit estimate of avoided forest loss

With the potential expansion of forest conservation programs spurred by climate-change agreements, there is a need to measure the extent to which such programs achieve their intended results. Conventional methods for evaluating conservation impact tend to be biased because they do not compare like areas or account for spatial relations. We assessed the effect of a conservation initiative that combined designation of protected areas with payments for environmental services to conserve over wintering habitat for the monarch butterfly (Danaus plexippus) in Mexico. To do so, we used a spatial-matching estimator that matches covariates among polygons and their neighbors. We measured avoided forest loss (avoided disturbance and deforestation) by comparing forest cover on protected and unprotected lands that were similar in terms of accessibility, governance, and forest type. Whereas conventional estimates of avoided forest loss suggest that conservation initiatives did not protect forest cover, we found evidence that the conservation measures are preserving forest cover. We found that the conservation measures protected between 200 ha and 710 ha (3-16%) of forest that is high-quality habitat for monarch butterflies, but had a smaller effect on total forest cover, preserving between 0 ha and 200 ha (0-2.5%) of forest with canopy cover >70%. We suggest that future estimates of avoided forest loss be analyzed spatially to account for how forest loss occurs across the landscape. Given the forthcoming demand from donors and carbon financiers for estimates of avoided forest loss, we anticipate our methods and results will contribute to future studies that estimate the outcome of conservation efforts.     

Human health risk assessment of environmental and dietary exposure to natural radionuclides in the Catalan stretch of the Ebro River, Spain

This study was aimed at assessing the levels of ²¹⁰Pb and ²¹⁰Po concentrations as well as gross alpha and beta activities in environmental monitors from the Catalan stretch of the Ebro River (Spain), potentially influenced by the presence of sediments with high concentrations of ²³⁸U and its decay chain daughters in the Flix reservoir. The chronic daily intake of ²¹⁰Pb and ²¹⁰Po through ingestion and inhalation of soils was evaluated, and the derived non-carcinogenic and carcinogenic risks were characterized. The low concentration of radioisotopes in soils resulted in a negligible annual effective dose. The levels of ²¹⁰Pb and ²¹⁰Po were determined in various groups of highly consumed food (fish and seafood, vegetables, fruits, and rice), and their dietary intake was calculated. The annual effective dose for the adult people from food intake was estimated in 3.3 × 10^???2 mSv, mostly due to ²¹⁰Po. Overall, the current radioactivity levels in the Catalan stretch of the Ebro River should not mean any additional health risk for the population living nearby. However, an integral assessment of the risks derived from exposure to other pollutants (e.g., metals and organochlorine compounds) jointly with radionuclides could be of great interest.     

ToSIA—A tool for sustainability impact assessment of forest-wood-chains

Within the forest sector, the sustainability concept has evolved from a narrow focus on sustainable wood production to a much broader evaluation of environmental, social, and economic sustainability for whole value chains. A new software tool - ToSIA - has been developed for assessing sustainability impacts of Forest-Wood-Chains (FWCs). In the approach, FWCs are defined as chains of production processes (e.g. harvesting-transport-industrial processing), which are linked with products (e.g. a timber frame house). Sustainability is determined by analysing environmental, economic, and social sustainability indicators for all the production processes along the FWC. The tool calculates sustainability values as products of the relative indicator values (i.e. indicator value expressed per unit of material flow) multiplied with the material flow entering the process. Calculated sustainability values are then aggregated for the segments of the FWC or for the complete chain. The sustainability impact assessment requires carefully specified system boundaries. ToSIA uses a data-oriented approach that is very flexible in the focus of the analysis and the selection of indicators of sustainability. An example of alternative Norway spruce management systems in Southern Germany and their effects on six sustainability indicators is presented. The less intensive management system with natural regeneration and motor-manual harvesting shows higher carbon storage and slightly less energy use. It creates more employment and higher labour costs, but the average rate of accidents is also higher. ToSIA offers a transparent and consistent methodological framework to assess sustainability impacts in the forest-based sector as affected, e.g. by changes in policies, market conditions, or technology. The paper discusses strengths and limitations of the approach and provides an outlook on further development perspectives of the methodology.     

Immobilization of heavy metals in polluted soils by the addition of zeolitic material synthesized from coal fly ash

The use of zeolitic material synthesized from coal fly ash for the immobilization of pollutants in contaminated soils was investigated in experimental plots in the Guadiamar Valley (SW Spain). This area was affected by a pyrite slurry spill in April 1998. Although reclamation activities were completed in a few months, residual pyrite slurry mixed with soil accounted for relatively high leachable levels of trace elements such as Zn, Pb, As, Cu, Sb, Co, Tl and Cd. Phytoremediation strategies were adopted for the final recovery of the polluted soils. The immobilization of metals had previously been undertaken to avoid leaching processes and the consequent groundwater pollution. To this end, 1100 kg of high NaP1 (Na6[(AlO2)6(SiO2)10] .15H2O) zeolitic material was synthesized using fly ash from the Teruel power plant (NE Spain), in a 10 m3 reactor. This zeolitic material was manually applied using different doses (10000-25000 kg per hectare), into the 25 cm topsoil. Another plot (control) was maintained without zeolite. Sampling was carried out 1 and 2 years after the zeolite addition. The results show that the zeolitic material considerably decreases the leaching of Cd, Co, Cu, Ni, and Zn. The sorption of metals in soil clay minerals (illite) proved to be the main cause contributing to the immobilization of these pollutants. This sorption could be a consequence of the rise in pH from 3.3 to 7.6 owing to the alkalinity of the zeolitic material added (caused by traces of free lime in the fly ash, or residual NaOH from synthesis).     

Sources and concentrations of indoor nitrogen dioxide in Barcelona, Spain

Sources and concentrations of indoor nitrogen dioxide (NO2) were examined in Barcelona, Spain, during 1996-1999. A total of 340 dwellings of infants participating in a hospital-based cohort study were selected from different areas of the city. Passive filter badges were used for indoor NO2 measurement over 7-30 days. Dwelling inhabitants completed a questionnaire on housing characteristics and smoking habits. Data on outdoor NO2 concentrations were available for the entire period of the study in the areas of the city where indoor concentrations were determined. Bivariate analysis was performed to investigate relationships between indoor NO2 concentrations on one hand and outdoor NO2 concentrations, housing, and occupant characteristics on the other. Stepwise multiple linear regression was performed with variables that were found to have a significant bivariate relationship. Indoor NO2 mean values ranged between 23.57 ppb in 1996 and 27.02 ppb in 1999, with the highest yearly value of 27.82 ppb in 1997. In the same time period, mean outdoor NO2 concentration ranged between 25.26 and 25.78 ppb with a peak of 30.5 ppb in 1998. Multiple regression analysis showed that principal sources of indoor NO2 concentrations were the use of a gas cooker, the absence of an extractor fan when cooking, and cigarette smoking. The absence of central heating was also associated with higher NO2 concentrations. Finally, each ppb increase in outdoor NO2 was associated with a 1% increase in indoor concentrations.     

Latitudinal and seasonal capacity of the surface oceans as a reservoir of polychlorinated biphenyls

The oceans play an important role as a global reservoir and ultimate sink of persistent organic pollutants (POPs) such as polychlorinated biphenyls congeners (PCBs). However, the physical and biogeochemical variables that affect the oceanic capacity to retain PCBs show an important spatial and temporal variability which have not been studied in detail, so far. The objective of this paper is to assess the seasonal and spatial variability of the ocean's maximum capacity to act as a reservoir of atmospherically transported and deposited PCBs. A level I fugacity model is used which incorporates the environmental variables of temperature, phytoplankton biomass, and mixed layer depth, as determined from remote sensing and from climatological datasets. It is shown that temperature, phytoplankton biomass and mixed layer depth influence the potential PCB reservoir of the oceans, being phytoplankton biomass specially important in the oceanic productive regions. The ocean's maximum capacities to hold PCBs are estimated. They are compared to a budget of PCBs in the surface oceans derived using a level III model that assumes steady state and which incorporates water column settling fluxes as a loss process. Results suggest that settling fluxes will keep the surface oceanic reservoir of PCBs well below its maximum capacity, especially for the more hydrophobic compounds. The strong seasonal and latitudinal variability of the surface ocean's storage capacity needs further research, because it plays an important role in the global biogeochemical cycles controlling the ultimate sink of PCBs. Because this modeling exercise incorporates variations in downward fluxes driven by phytoplankton and the extent of the water column mixing, it predicts more complex latitudinal variations in PCBs concentrations than those previously suggested.