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There is a paucity of comprehensive air quality data from urban areas in the Middle East. In this study, portable instrumentation was used to measure size-fractioned aerosol number, mass, and black carbon concentrations in Amman and Zarqa, Jordan. Submicron particle number concentrations at stationary urban background sites in Amman and Zarqa exhibited a characteristic diurnal pattern, with the highest concentrations during traffic rush hours (2&ndash, 5 &times, 104 cm&minus, 3 in Amman and 2&ndash, 7 &times, 3 in Zarqa). Super-micron particle number concentrations varied considerably in Amman (1&ndash, 10 cm&minus, 3). Mobile measurements identified spatial variations and local hotspots in aerosol levels within both cities. Walking paths around the University of Jordan campus showed increasing concentrations with proximity to main roads with mean values of 8 &times, 3, 87 &micro, g/m3, 62 &micro, g/m3, and 7.7 &micro, g/m3 for submicron, PM10, PM2.5, and black carbon (BC), respectively. Walking paths in the Amman city center showed moderately high concentrations (mean 105 cm&minus, 3, 120 &micro, g/m3, 85 &micro, g/m3, and 8.1 &micro, g/m3 for submicron aerosols, PM10, PM2.5, and black carbon, respectively). Similar levels were found along walking paths in the Zarqa city center. On-road measurements showed high submicron concentrations (&gt, 105 cm&minus, 3). The lowest submicron concentration (&lt, 3) was observed near a remote site outside of the cities.

Of a wide variety of international forest research and monitoring networks, several networks are dedicated to the effects of climate change on forests, while the effects of anthropogenic pollutants on forests have been a major area for both monitoring and research for decades. The large amounts of data already obtained within existing monitoring programmes and large-scale international projects can be used to increase understanding of the state and potential of forest mitigation and adaptation to climate change in a polluted environment, and a major challenge now is to evaluate and integrate the presently available databases. We present a meta-database with the main goal to highlight available data and integrate the information about research and monitoring of selected European Research and Monitoring Networks (ERMNs). Depending on the selected ERMNs, the list of variables and the measurement units differ widely in the databases. As a result, activities related to the identification, evaluation and integration of the presently available databases are important for the scientific community. Furthermore, and equally important, the recognition of current knowledge gaps and future needed research is made easier. This analysis suggests that: ground-level ozone is under-investigated, although it is one of the pollutants of greatest concern to forests; in addition to CO2, long-term other greenhouse gasses (GHG) flux measurements should be carried out; there is still a need of improving links between monitoring of atmospheric changes and impacts on forests; research-oriented manipulative experiments in the forests are missing.

Studies of global environmental change make extensive use of scenarios to explore how the future can evolve under a consistent set of assumptions. The recently developed Shared Socioeconomic Pathways (SSPs) create a framework for the study of climate-related scenario outcomes. Their five narratives span a wide range of worlds that vary in their challenges for climate change mitigation and adaptation. Here we provide background on the quantification that has been selected to serve as the reference, or ‘marker’, implementation for SSP2. The SSP2 narrative describes a middle-of-the-road development in the mitigation and adaptation challenges space. We explain how the narrative has been translated into quantitative assumptions in the IIASA Integrated Assessment Modelling Framework . We show that our SSP2 marker implementation occupies a central position for key metrics along the mitigation and adaptation challenge dimensions. For many dimensions the SSP2 marker implementation also reflects an extension of the historical experience, particularly in terms of carbon and energy intensity improvements in its baseline. This leads to a steady emissions increase over the 21st century, with projected end-of-century warming nearing 4 °C relative to preindustrial levels. On the other hand, SSP2 also shows that global-mean temperature increase can be limited to below 2 °C, pending stringent climate policies throughout the world. The added value of the SSP2 marker implementation for the wider scientific community is that it can serve as a starting point to further explore integrated solutions for achieving multiple societal objectives in light of the climate adaptation and mitigation challenges that society could face over the 21st century.

Urbanization and rising household incomes in India have led to growing transport demand, particularly during 1990-2010. Emissions from transportation have been implicated in air quality and climate effects. In this work, emissions of particulate matter (PM2.5 or mass concentration of particles smaller than 2.5 um diameter), black carbon (BC) and organic carbon (OC), were estimated from the transport sector in India, using detailed technology divisions and regionally measured emission factors. Modes of transport addressed in this work include road transport, railways, shipping and aviation, but exclude off-road equipment like diesel machinery and tractors. For road transport, a vehicle fleet model was used, with parameters derived from vehicle sales, registration data, and surveyed age-profile. The fraction of extremely high emitting vehicles, or superemitters, which is highly uncertain, was assumed as 20%. Annual vehicle utilization estimates were based on regional surveys and user population. For railways, shipping and aviation, a top-down approach was applied, using nationally reported fuel consumption. Fuel use and emissions from on-road vehicles were disaggregated at the state level, with separate estimates for 30 cities in India. The on-road fleet was dominated by two-wheelers, followed by four-and three-wheelers, with new vehicles comprising the majority of the fleet for each vehicle type. A total of 276 (-156, 270) Gg/y PM2.5, 144 (-99, 207) Gg/y BC, and 95 (-64, 130) Gg/y OC emissions were estimated, with over 97% contribution from on-road transport. Largest emitters were identified as heavy duty diesel vehicles for PM2.5 and BC, but two-stroke vehicles and superemitters for OC. Old vehicles (pre-2005) contributed significantly more (similar to 70%) emissions, while their share in the vehicle fleet was smaller (similar to 45%). Emission estimates were sensitive to assumed superemitter fraction. Improvement of emission estimates requires on-road emission factor measurements for all vehicle types and a better understanding of vehicle utilization and superemitter fraction. (C) 2014 Elsevier Ltd. All rights reserved.

Of a wide variety of international forest research and monitoring networks, several networks are dedicated to the effects of climate change on forests, while the effects of anthropogenic pollutants on forests have been a major area for both monitoring and research for decades. The large amounts of data already obtained within existing monitoring programmes and large-scale international projects can be used to increase understanding of the state and potential of forest mitigation and adaptation to climate change in a polluted environment, and a major challenge now is to evaluate and integrate the presently available databases. We present a meta-database with the main goal to highlight available data and integrate the information about research and monitoring of selected European Research and Monitoring Networks (ERMNs). Depending on the selected ERMNs, the list of variables and the measurement units differ widely in the databases. As a result, activities related to the identification, evaluation and integration of the presently available databases are important for the scientific community. Furthermore, and equally important, the recognition of current knowledge gaps and future needed research is made easier. This analysis suggests that: ground-level ozone is under-investigated, although it is one of the pollutants of greatest concern to forests; in addition to CO2, long-term other greenhouse gasses (GHG) flux measurements should be carried out; there is still a need of improving links between monitoring of atmospheric changes and impacts on forests; research-oriented manipulative experiments in the forests are missing.

Young Norway spruce (Picea abies (L.) Karst.) trees were exposed to elevated CO2 (0.8 mL L(-1)), SO2 (0.06 mu L L(-1)), and elevated CO2 and SO2 (0.8 mL L(-1) and 0.06 mu L L(-1), respectively) for three months. Exposure to elevated CO2 resulted in an increased biomass production of the needles, while the pigment content was decreased. Exposure to SO2 hardly affected growth and pigment contents. Chlorophyll/carotenoid- and chlorophyll a/chlorophyll b-ratios were not affected by either CO2 or SO2. The epoxidation state of the xanthophyll-cycle was changed upon SO2-exposure, due to a higher zeaxanthin and a lower violaxanthin content. Chlorophyll fluorescence measurements showed F-v/F-m-ratios of 0.7 or higher for all needles, which indicated a healthy photosynthetic apparatus. Exposure to SO2 resulted in increased foliar contents of sulfate, total glutathione (reduced and oxidized form), cyst(e)ine, and a slightly more reduced redox state of glutathione. Exposure to elevated CO2 resulted in a slight decrease in glutathione contents, but it did not affect sulfate or cyst(e)ine contents of the spruce needles. Neither ascorbic acid content nor its redox state were affected by CO2 or SO2. The effects of CO2 and SO2 were independent from each other, since significant interactions CO(2)xSO(2) were not observed.

Young Norway spruce (Picea abies (L.) Karst.) trees were exposed to elevated CO2 (0.8 mL L(-1)), SO2 (0.06 mu L L(-1)), and elevated CO2 and SO2 (0.8 mL L(-1) and 0.06 mu L L(-1), respectively) for three months. Exposure to elevated CO2 resulted in an increased biomass production of the needles, while the pigment content was decreased. Exposure to SO2 hardly affected growth and pigment contents. Chlorophyll/carotenoid- and chlorophyll a/chlorophyll b-ratios were not affected by either CO2 or SO2. The epoxidation state of the xanthophyll-cycle was changed upon SO2-exposure, due to a higher zeaxanthin and a lower violaxanthin content. Chlorophyll fluorescence measurements showed F-v/F-m-ratios of 0.7 or higher for all needles, which indicated a healthy photosynthetic apparatus. Exposure to SO2 resulted in increased foliar contents of sulfate, total glutathione (reduced and oxidized form), cyst(e)ine, and a slightly more reduced redox state of glutathione. Exposure to elevated CO2 resulted in a slight decrease in glutathione contents, but it did not affect sulfate or cyst(e)ine contents of the spruce needles. Neither ascorbic acid content nor its redox state were affected by CO2 or SO2. The effects of CO2 and SO2 were independent from each other, since significant interactions CO(2)xSO(2) were not observed.

Objectives This is the first research study to compare among female, non-smoker workers: (a) the exposure to benzene, toluene and xylenes (BTXs) in urban air during work in the street (traffic policewomen, TP) vs. work in vehicles (police drivers, PD); (b) the exposure to BTXs in urban environments (in street and in car) vs. rural environments (roadwomen, RW); (c) the values of blood benzene, urinary trans, trans muconic acid (t,t-MA) and urinary S-phenylmercapturic acid (S-PMA) in urban areas (in street and in car) vs . rural areas. Methods Passive personal samplings and data acquired using fixed monitoring stations located in different areas of the city were used to measure environmental and occupational exposure to BTXs during the work shift in 48 TP, 21 PD and 22 RW. In the same study subjects, blood benzene, t,t-MA and S-PMA were measured at the end of each work shift. Results Personal exposure of urban workers to benzene seemed to be higher than the exposure measured by the fixed monitoring stations. Personal exposure to benzene and toluene was (a) similar among TP and PD and (b) higher among urban workers compared to rural workers. Personal exposure to xylenes was (a) higher in TP than in PD and (b) higher among urban workers compared to rural workers. Blood benzene, t,t-MA and S-PMA levels were similar among TP and PD, although the blood benzene level was significantly higher in urban workers compared to rural workers. In urban workers, airborne benzene and blood benzene levels were significantly correlated. Conclusions Benzene is a human carcinogen, and BTXs are potential reproductive toxins at low dose exposures. Biological and environmental monitoring to assess exposure to BTXs represents a preliminary and necessary tool for the implementation of preventive measures for female subjects working in outdoor environments.

Trend analysis and forecasting of time series data on air-pollutants is important to design effective measures to minimize damages to ecosystems and human health. In this study, autoregressive, moving average, autoregressive-moving average and autoregressive integrated moving average processes of different order were implemented to examine patterns of depositions and emissions. Analysis was undertaken to examine stationarity of the series or to design a method to create stationary series. The model that satisfied selected statistical criteria was chosen to make forecasts. Forecasts of depositions were compared with critical loads by watersheds. The findings of this study indicated that both wet depositions and emissions of SO2 and NOx data exhibited non-stationarity. After removing non-stationarity, suitable time-series model was selected for short-run forecasting (1994 to 2005). The resulting depositions and emissions data were examined with respect to their long-run movement and critical deposition loadings. The analysis showed that excess wet depositions of SO2 and NO3 would be major problems at least for ten years. Most of these problems are observed in Atlantic Canada and few watersheds in Quebec and Ontario. Although emissions of SO2 have declined, emissions of NOx remained unchanged or increased compared to the 1980 level. Considering the fact that these pollutants contribute to acidification, eutrophication and formation of secondary particulates that are hazardous to human health, it is necessary to find ways of further reducing emissions and depositions of these pollutants. While substantial progress has been made with respect to reduction of SO2 emissions (especially in Canada), the analysis presented in this study indicated that there must be substantially more reductions to ensure the protection of sensitive ecosystems. Thus, evidences similar to those presented in this study should be gathered to initiate negotiations for reductions beyond the 2005 or 2010 commitments.

A non-thermal plasma rector with a catalytic electrode made of sintered metal fibres (SMFs) was tested for the oxidative decomposition of a model VOC toluene. The input energy was varied in the range 160-295 J/I by varying the applied voltage between 12.5 and 22.5 kV at 200 Hz. Influence of various parameters like toluene concentration, SMF modification by Mn and Co oxides, input energy and ozone formation was studied. It has been observed that plasma catalytic approach is very effective for total oxidation of toluene at low input energy, especially at toluene concentration

Young Norway spruce (Picea abies (L.) Karst.) trees were exposed to elevated CO2 (0.8 mL L(-1)), SO2 (0.06 mu L L(-1)), and elevated CO2 and SO2 (0.8 mL L(-1) and 0.06 mu L L(-1), respectively) for three months. Exposure to elevated CO2 resulted in an increased biomass production of the needles, while the pigment content was decreased. Exposure to SO2 hardly affected growth and pigment contents. Chlorophyll/carotenoid- and chlorophyll a/chlorophyll b-ratios were not affected by either CO2 or SO2. The epoxidation state of the xanthophyll-cycle was changed upon SO2-exposure, due to a higher zeaxanthin and a lower violaxanthin content. Chlorophyll fluorescence measurements showed F-v/F-m-ratios of 0.7 or higher for all needles, which indicated a healthy photosynthetic apparatus. Exposure to SO2 resulted in increased foliar contents of sulfate, total glutathione (reduced and oxidized form), cyst(e)ine, and a slightly more reduced redox state of glutathione. Exposure to elevated CO2 resulted in a slight decrease in glutathione contents, but it did not affect sulfate or cyst(e)ine contents of the spruce needles. Neither ascorbic acid content nor its redox state were affected by CO2 or SO2. The effects of CO2 and SO2 were independent from each other, since significant interactions CO(2)xSO(2) were not observed.

Catalytic purification of air containing 250 ppm of toluene assisted by non-thermal plasma was carried out with a novel dielectric barrier discharge (DBD) reactor with an inner electrode made of sintered metal fibers (SMF). The optimization of the reactor performance was carried out by modifying the SMF with Mn and Co oxides, varying the voltage from 12.5 to 22.5 W and the frequency in the range of 200-450 Hz. Under the experimental conditions used, the MnOx/SMF showed better activity than CoOx/SMF and SMF during the total oxidation of toluene. The complete oxidation of 250 ppm of toluene was possible with the MnOx/SMF catalytic electrode at the specific input energy (SIE) of similar to 1650 J/l. A higher SIE of similar to 2100 J/l was required with CoOx/SMF for the total oxidation of toluene to CO2. The better performance of the MnOx/SMF compared to other catalytic electrodes seems to be related to the formation of short-lived species by the in situ decomposition of ozone. XPS analysis of the solid deposit formed on the electrode surface shows the formation of carbonaceous species containing oxygen and nitrogen groups. (c) 2006 Published by Elsevier B.V.

[1] During the last 5 years, information on the regional tropospheric ozone levels over the eastern Mediterranean has become available but was confined to measurements at ground level. Here available information is expanded with measurements at two more rural ground level sites spanning 8 latitude, ozonesonde ascents, lidar observations, ship cruises, and aircraft flights. During wintertime the ozone monthly values are 1020 ppbv higher than values at other European sites, while during summertime the values are comparable. This results in regional ozone background levels in the area that are above the European Union (EU) 32 ppb/ 24 hours phytotoxicity limit during the entire year. Late spring lidar observations show that south and southwestern synoptic flows which are associated with Saharan dust events result in lower ozone above the planetary boundary layer (PBL) by 20-35 ppbv as compared to these during northerly flows, which transport air from continental Europe. These lidar observations along with ship measurements during July show that ozone is enhanced 1.5-2.2 times in the continental outflow, when compared to aged maritime air or air from the African continent. These results along with ozonesonde observations suggest that ozone abatement in the area is largely beyond the control of regional emissions and can be controlled only with emission reductions on a European scale. During September, measured background NO and NO2 levels between 3 and 4.5 km above sea level ranged from 1 to 221 pptv and from 102 to 580 pptv, respectively. The troposphere contains around 40-70 Dobson units of ozone during summer and around 20-30 Dobson units during winter.