An air quality balance index estimating the total amount of air pollutants at ground level

A new index named Air Quality Balance Index (AQBI), which is able to characterise the amount of pollution level in a selected area, is proposed. This index is a function of the ratios between pollutant concentration values and their standards; it aims at identifying all situations in which there is a possible environmental risk even when several pollutants are below their limit values but air quality is reduced. AQBI is evaluated by using a high-resolution three-dimensional dispersion model: the air concentration for each substance is computed starting from detailed emissions sources: point, line and area emissions hourly modulated. This model is driven with accurate meteorological data from ground stations and remote sensing systems providing vertical profiles of temperature and wind; these data are integrated with wind and temperature profiles at higher altitudes obtained by a Local Area Model. The outputs of the dispersion model are compared with pollutant concentrations provided by measuring stations, in order to recalibrate emission data. A three-dimensional high resolution grid of AQBI data is evaluated for an industrial area close to Alessandria (Northern Italy), assessing air quality and environmental conditions. Performance of AQBI is compared with the Air Quality Index (AQI) developed by the U.S. Environmental Protection Agency. AQBI, computed taking into account all pollutants, is able to point out situations not evidenced by AQI, based on a preset limited number of substances; therefore, AQBI is a good tool for evaluating the air quality either in urban and in industrial areas. The AQBI values at ground level, in selected points, are in agreement with in situ observations.     

Seasonal and spatial variability of polychlorinated biphenyls (PCBs) in vegetation and cow milk from a high altitude pasture in the Italian Alps

The seasonal and spatial variability of polychlorinated biphenyls (PCBs) in vegetation and cow milk was studied in a high altitude pasture in the Alps (1900 m a.s.l.). PCB contamination in vegetation shows a concentration peak in June, which is mainly interpreted as the consequence of a temporary PCB enrichment of the air layer above the ground due to net emission fluxes from the soil. A three compartment dynamic model was developed to test this hypothesis. The North/South enrichment factor in the vegetation was 1.5-1.6 for penta- and hexa-substituted congeners and 1.7 for hepta- and octa-PCBs, according to the effect of temperature on compounds having higher K_oa values. Milk concentrations followed the vegetation seasonal trend. The congener abundance in milk is in agreement with the biotransformation susceptibility, absorption efficiency and residence time of the different congeners in dairy cows.     

Organotins in the sediments of the Zuari estuary, west coast of India

Industrial use of organotins such as butyltins and phenyltins has increased several folds during the last two decades. Butyltins and phenyltins are synthetic, multipurpose chemicals, which have been extensively used in marine antifouling paints. They have been known to be extremely poisonous to mollusc fishery resources (oysters, clams, etc.). Contamination of Zuari estuary sediments was assessed by quantitative determination of butyltins and phenyltins by using GC-MS using the electron ionization mode. Butyltins predominated in the whole area over phenyltins. Butyltins contributed about 70-90% of the organotins in general. The concentration of butyltins in sediments ranged from 20 to 7621 ng Sn/g. The concentration of phenyltins in sediments ranged from 0 to 46 ng Sn/g. Degradation indices for butyltins and phenyltins were calculated. The Butyltin degradation index (BDI) for the Zuari sediments ranged from 0 to 2.7 indicating a lot of fresh input of butyltins in the estuary and a lower degradation rate. The phenyltin degradation index (PhDI) ranged from 1 to 10 implying that different processes were prevalent at different stations. The observed organotin levels in the Zuari estuary indicate some highly localized areas of contamination which are severe enough to cause harmful effects on marine flora and fauna. Therefore, there is a need to regulate the use of butyltins and phenyltins as biocides in marine antifouling paints.     

Gas- and particle-phase distribution of polycyclic aromatic hydrocarbons in two-stroke, 50-cm3 moped emissions

Gas- and particle-phase polycyclic aromatic hydrocarbons (PAHs) concentrations evaluated in the exhaust of 10 two-stroke, 50-cm³ mopeds belonging to three different levels of emission legislation (EURO-0, EURO-1 and EURO-2) were used to assess the prevalent mechanism driving the gas/particle partitioning of PAHs in moped exhaust. Sampling was performed on a dynamometer bench both during the “cold-start” and the “hot” phases of the ECE-47 driving cycle. Gas and particulate phase PAHs were collected on polyurethane foam (PUF) plugs and 47-mm Pallflex T60A20 filters, respectively, under isokinetic conditions by using sampling probes inserted into the dilution tunnel of a Constant Volume Sampling – Critical Flow Venturi (CVS–CFV) system.The results show that semi-volatile PAHs were predominantly partitioned to the particle phase. The soluble organic fraction (SOF) of the collected particulates ranged between 72 and 98%. Measured total suspended particulate matter normalized partition coefficients (K_p) were predicted within a factor of 3–5 by assuming absorption into the organic fraction according to a model developed by Harner and Bidleman [Harner, T., Bidleman, T.F., 1998. Octanol–air partition coefficient for describing particle/gas partitioning of aromatic compounds in urban air. Environmental Science & Technology 32, 1494–1502.]. This suggests that the gas/particle partitioning in moped exhaust is mainly driven by the high fraction of organic matter of the emitted particles and that absorption could be the main partitioning mechanism of PAHs.     

Intra- and inter-annual variability of VOC emissions from natural and semi-natural vegetation in Europe and neighbouring countries

Biogenic VOC emission estimates from the earth's surface are crucial input parameters in air quality models. Knowledge accumulated in the last years about BVOC source distributions and chemical compound species emission profiles in Europe as well as the demand of air quality modellers for a finer resolution in space and time of BVOC estimates have led to the set-up of new emission modelling systems. An updated fast BVOC emission modelling platform explicitly considering the seasonality of emission potentials and leaf temperature gradients in forest canopies by the semi-empirical emission module (seBVOC) will be proposed and used for estimating hourly values of chemical compound-specific emissions in Europe (33–68° north; 10° west to 40° east) in the years 1997, 2000, 2001, and 2003. Spatial resolution will be 10 km by 10 km. The database used contains latest land and forest distributions, updated foliar biomass densities, leaf area indices (LAI), and plant as well as chemical compound-specific emission potentials, if available. Meteorological input parameters for the respective years will be generated using the non-hydrostatic meteorological model MM5. Highest BVOC emissions occur in daytime hours around noon from the end of May to mid-August in the Mediterranean area and from the mid of June to the end of July in the boreal forests. Comparison of 3 BVOC model approaches will reveal that for July 2003, the European isoprene and monoterpene totals range from 1124 Gg to 1446 Gg and from 338 Gg to 1112 Gg, respectively. Small-scale deviations may be as high as ±0.6 Mg km^?2 for July 2003, reflecting the current uncertainty range for BVOC estimates. Key sources of errors in inventories are still insufficiently detailed land use data for some areas and lacking chemically speciated plant-specific emission potentials in particular in boreal, south-eastern, and northern African landscapes. The hourly emissions of isoprene, speciated terpenes, and oxyVOC have been made available by the NatAir database.     

Soil erosion tolerance and water runoff control: minimum environmental standards

Council Regulations (EC) No 1257/1999 and the EU Soil Thematic Strategy give great importance to soil and land conservation to develop knowledge driven governance for rural development. In the hilly areas of Italy cultivated intensively, and especially in the ones devoted to viticulture, agricultural practices determine high loss of soil with consequent degradation of the soil resource. In addition to it, offsite effects of soil erosion can be unsustainable, due to sediment transfer to the channel network and infrastructures. In order to achieve a sustainable rural development there is a need for tools and instruments to allow European regional administrations, to develop, implement, manage and monitor rural development plans. To counteract the environmental threats intensified by agricultural activity, the environmental functions “soil erosion control” and “water runoff control” were investigated in the Chianti area by using GIS. To determine the EMR (Environmental Minimum Requirements) values for soil erosion the “regeneration” capability of soils was considered, and the value of estimated soil loss was compared with the value of soil reformation. A scenario analysis was also performed to evaluate the effectiveness of the agroenvironmental measure “grass cover” in reducing erosion. The concept of tolerable erosion based on soil productivity and soil reformation rate only is reductive and off-site effects of soil erosion should be also taken into account. For this reason, it was proposed to extend the concept of hydrogeological risk to soil erosion by implementing the notion of soil erosion tolerance (T) with the new concept of environmental risk of soil erosion (ERSE). The new ERSE index takes into account all the in- and off-farm externalities of soil erosion. For this reason, it can be considered an aggregated environmental indicator that enables policy makers to evaluate the impacts of soil erosion by following an holistic approach.     

Proximity to wood industries and respiratory symptoms in children: a sensitivity analysis

Increased prevalence of respiratory and irritation symptoms was found in children who live near a large wood industrial park. Proximity to the wood industries was used as indicator of exposure. This study describes a sensitivity analysis for the results of the survey. All the children (3-14 years) living in the area were surveyed through a parental questionnaire (n = 3854) and their addresses were geocoded. The distances from each child's home and school to the closest industry were combined, weighted and used as an indicator of exposure. A sensitivity analysis was performed to check 1) the robustness of the results to the choice of weights used for defining the exposure indicator, 2) the effect of outliers on risk estimates and 3) the sensitivity on the functional form used for modeling the dose-response function. The choice of the weights did not influence the association between proximity to the industries and respiratory symptoms. Excluding the subjects who lived far away from the industries showed that in a radius of 5 km from the industries the study did not had enough power to estimate a gradient in the dose-response function. Besides, results were sensitive to the choice of the functional form used for modeling the minimum distance. The sensitivity analyses confirmed the overall increasing trend of respiratory symptoms with proximity to the industries and pointed out that all the assumptions made for defining a proxy of exposure need to be carefully checked.     

Impact of elevated CO(2) and nitrogen fertilization on foliar elemental composition in a short rotation poplar plantation

The experiment was carried out on a short rotation coppice culture of poplars (POP-EUROFACE, Central Italy), growing in a free air carbon dioxide enriched atmosphere (FACE). The specific objective of this work was to study whether elevated CO(2) and fertilization (two CO(2) treatments, elevated CO(2) and control, two N fertilization treatments, fertilized and unfertilized), as well as the interaction between treatments caused an unbalanced nutritional status of leaves in three poplar species (P. x euramericana, P. nigra and P. alba). Finally, we discuss the ecological implications of a possible change in foliar nutrients concentration. CO(2) enrichment reduced foliar nitrogen and increased the concentration of magnesium; whereas nitrogen fertilization had opposite effects on leaf nitrogen and magnesium concentrations. Moreover, the interaction between elevated CO(2) and N fertilization amplified some element unbalances such as the K/N-ratio.     

Particle-phase Polycyclic Aromatic Hydrocarbon Emissions from Non-catalysed, In-use Four-stroke Scooters

Metals and radionuclide levels in marine birds of the Aleutians are of interest because they are part of subsistence diets of the Aleut people, and can also serve as indicators of marine pollution. We examined geographic and species-specific variations in concentrations of radionuclides in birds and their eggs from Amchitka, the site of underground nuclear tests from 1965 to 1971, and Kiska Islands (a reference site) in the Aleutians, and the levels of lead, mercury and cadmium in eggs. In 2004 we collected common eiders (Somateria mollissima), tufted puffins (Fratercula cirrhata), pigeon guillemot (Cepphus columba) and glaucous-winged gulls (Larus glaucescens) from Amchitka and Kiska, and eggs from eiders and gulls from the two island. We also collected one runt bald eagle (Haliaeetus leucocephalus) chick from both Amchitka and Kiska Islands. For most species, the levels of radionuclide isotopes were below the minimum detectable activity levels (MDA). Out of 74 cesium-137 analyses, only one composite (gulls) was above the MDA, and out of 14 composites tested for plutonium (Pu-239, 240), only one exceeded the MDA (a guillemots). Three composites out of 14 tested had detectable uranium-238. In all cases, the levels were low and close to the MDAs, and were below those reported for other seabirds. There were significant interspecific differences in metal levels in eggs: gulls had significantly higher levels of cadmium and mercury than the eiders, and eiders had higher levels of lead than gulls. There were few significant differences as a function of island, but eiders had significantly higher levels of cadmium in eggs from Kiska, and gulls had significantly higher levels of mercury on Kiska. The levels of cadmium and mercury in eggs of eiders and gulls from this study were above the median for cadmium and mercury from studies in the literature. The levels of mercury in eggs are within the range known to affect avian predators, but seabirds seem less vulnerable to mercury than other birds. However, the levels of mercury are within the action levels for humans, suggesting some cause for concern if subsistence Aleuts eat a large quantity of eggs.