Monitoring Nitrogen Dioxide and its Effects on Asthmatic Patients: Two Different Strategies Compared

Objectives: To develop a `methodologyassessment' to evaluate the strengths and theweaknesses of two different epidemiological approachesand to identify the best suited monitoring strategy tomeasure the effects of `normal levels' of nitrogendioxide exposure on the health of an urban population.Methodology: all exposures to nitrogen dioxidewere determined with passive samplers, each samplerconsisting of 3 measuring Palmes tubes. In the firststudy the nitrogen dioxide exposure was assessed in 23school children (11 asthmatic and 12 non asthmatic).Children wore samplers for a week and parallelmeasurements were made in their kitchens, in bedroomsand outside their homes. The second study consisted ina case-control study where the relative risk ofhospital admission was calculated considering nitrogendioxide levels in a city of northern Italy. 110asthmatic patients were compared to a control group of 5322 people.Results: Personal sampler measurementshighlighted significant differences in exposure when nitrogen dioxide atmospheric levels were compared inasthmatic and healthy children (p<0.05). No otherparameters were significant in the two groups. Asignificant action of atmospheric nitrogen dioxide onhospital admission was demonstrated (p<0.01).Conclusions: Although a cause-effect relation assuch cannot be identified, the studies show a relationbetween the exposure to nitrogen dioxide and thepresence of adverse effects on people's health.However the `disadvantage' is for subjects withasthmatic pathologies, compared to the others. Tomanage this problem most effectively, a combinedapproach with the activation of specific personalmonitoring campaigns of the subjects with verifiedrisk seems necessary. This requires `reading' the dataresulting from most extensive and up to dateinformation systems, capable of a thorough controlboth of the living environment and of the clinicaloutcome of the whole population.     

Electrophysiological and behavioural responses of Aphidius ervi (Hymenoptera: Braconidae) to tomato plant volatiles

Flight responses of the aphid parasitoid Aphidius ervi to tomato volatiles have recently demonstrated that different plant stresses can lead to increases in attractiveness for this parasitoid. For example, infestation of tomato plants by the aphid Macrosiphum euphorbiae results in the overexpression of defensive genes, as well as the release of volatile compounds that attract aphid parasitoids. Here, we determine which of the induced compounds elicit a significant electrophysiological response from parasitoid antennae. Compounds shown to be detected at the antennal level were then tested at a range of doses in a wind tunnel assay. A significant electroantennogram response was demonstrated for three compounds, (8S,9R)-(E)-caryophyllene, methyl salicylate, and (Z)-3-hexen-1-ol, over four concentrations. These compounds proved to be significantly attractive in the wind tunnel at a rate not always proportionally dependent upon the dose. The practical implications of these findings are discussed in the framework of sustainable control for pest aphids in agriculture.     

Multi-metric evaluation of the models WARM,CropSyst, and WOFOST for rice

WARM (Water Accounting Rice Model) simulates paddy rice (Oryza sativa L.), based on temperature-driven development and radiation-driven crop growth. It also simulates: biomass partitioning, floodwater effect on temperature, spikelet sterility, floodwater and chemicals management, and soil hydrology. Biomass estimates from WARM were evaluated and compared with the ones from two generic crop models (CropSyst, WOFOST). The test-area was the Po Valley (Italy). Data collected at six sites from 1989 to 2004 from rice crops grown under flooded and non-limiting conditions were split into a calibration (to estimate some model parameters) and a validation set. For model evaluation, a fuzzy-logic based multiple-metrics indicator (MQI) was used: 0 (best) ≤ MQI ≤ 1 (worst). WARM estimates compared well with the actual data (mean MQI = 0.037 against 0.167 and 0.173 with CropSyst and WOFOST, respectively). On an average, the three models performed similarly for individual validation metrics such as modelling efficiency (EF > 0.90) and correlation coefficient (R > 0.98). WARM performed best in a weighed measure of the Akaike Information Criterion: (worst) 0<wk<1$0<w_k<1$ (best), considering estimation accuracy and number of parameters required to achieve it (mean wk=0.983$w_k=0.983$ against 0.007 and ∼0.000 with CropSyst and WOFOST, respectively). WARM results were sensitive to 30% of the model parameters (ratio being lower with both CropSyst, <10%, and WOFOST, <20%), but appeared the easiest model to use because of the lowest number of crop parameters required (10 against 15 and 34 with CropSyst and WOFOST, respectively). This study provides a concrete example of the possibilities offered using a range of assessment metrics to evaluate model estimates, predictive capabilities, and complexity.     

Customisation of the decision support system MOIRA-PLUS for applications to the marine environment

The present short communication describes a technique to customise the decision system MOIRA-PLUS for applications to the marine environment. MOIRA-PLUS was originally designed to predict the behaviour of ¹³⁷Cs and ⁹⁰Sr in fresh water ecosystems and to evaluate the environmental, social and economic impacts of selected countermeasures aimed at restoring the polluted environment and at reducing the doses to man. An example of application for predicting the concentration of radiocaesium of Chernobyl origin in the Mediterranean Sea is described and discussed. The technique allows the user to easily integrate existing state-of-the-art box models of sea water circulation into the MOIRA-PLUS decision system.     

Predicting the effects of ionising radiation on ecosystems by a generic model based on the Lotka–Volterra equations

The present work describes a model for predicting the population dynamics of the main components (resources and consumers) of terrestrial ecosystems exposed to ionising radiation. The ecosystem is modelled by the Lotka–Volterra equations with consumer competition. Linear dose–response relationships without threshold are assumed to relate the values of the model parameters to the dose rates. The model accounts for the migration of consumers from areas characterised by different levels of radionuclide contamination. The criteria to select the model parameter values are motivated by accounting for the results of the empirical studies of past decades. Examples of predictions for long-term chronic exposure are reported and discussed.     

Ozone oxidation and aerobic biodegradation with spent mushroom compost for detoxification and benzo(a)pyrene removal from contaminated soil

The combination of ozonation and spent mushroom compost (SMC)-mediated aerobic biological treatment was investigated in the removal of benzo(a)pyrene from contaminated soil. The performances of the process alone and combined were evaluated in terms of benzo(a)pyrene removal efficiency, mineralization efficiency (as total organic carbon removal), and soil residual toxicity (phytotoxicity to Lepidium Sativum and toxicity to Vibrio fischeri). In spite of the removal efficiency (35%) obtained by SMC-mediated biological process as a stand-alone treatment, the combined process showed a benzo(a)pyrene concentration reduction higher than 75%; the best removal (82%) was observed after 10 min pre-ozonation treatment. In particular, ozonation improved the biodegradability of the contaminant, as confirmed by the increase of CO(2) production (close to 70% compared to the control), mineralization (greater than 60%) and bacterial density (which increased by two orders of magnitude). Moreover, according to phytotoxicity tests on L. Sativum, the aerobic biological process of pre-ozonated soil decreased toxicity. According to the results achieved in the present study, ozonation pre-treatment showed an high potential to overcome the limitation of bioremediation of recalcitrant compound, but it should be carefully operated in order to maximize PAH removal efficiency as well as to minimize soil residual toxicity which can result from the formation of the oxidation intermediates.     

Submarine wastewater discharges: dispersion modelling in the Northern Adriatic Sea

Background, aim and scope   

Opposite interests must coexist in coastal areas: the presence of significant cities and urban centres, of touristic and recreational areas, and of extensive shellfish farming. To avoid local pollution caused by treated wastewaters along the Northern Adriatic coast (Friuli Venezia-Giulia and Veneto regions), marine outfall systems have been constructed. In this study, the application of a numerical dispersion model is used to support the traditional monitoring methods in order to link information concerning the hydrodynamic circulation and the microbiological features, to evaluate possible health risks associated with recreational and coastal shellfish farming activities. The study is a preliminary analysis of the environmental impact of wastewater treatment plants (WWTPs) with submarine discharge outfalls. It also could be useful for the water profile definition according to the Directive 2006/7/EC on the quality of bathing water and for the integrated areal analysis (Ostoich et al. 2006), to define the area of influence of each submarine discharge point.     

Atmospheric pollution by PAHs, PCDD/Fs and PCBs simultaneously collected at a regional background site in central Italy and at an urban site in Rome

Concentrations of PAHs and PCDD/Fs were measured throughout one year, and PCBs during the second semester, at a rural site in a natural park representative of background pollution in central Italy; results were compared with simultaneous measurements performed at an urban site in Rome 60km away. Twenty-four daily samples were collected at each site by a high-volume PM(10) sampler from February 2000 to January 2001. After ultrasonic extraction and clean-up by TLC, samples were analysed by GC-MS. Mean concentrations of benzo[a]pyrene (BaP, as a marker of carcinogenic PAHs), summation operatorPCDD/Fs and summation operator64 PCBs in Rome were, respectively: 1.1ngm(-3), 65fgWHO-TEQm(-3), 553pgm(-3). The background concentrations were, respectively: 0.016ngm(-3), 3fgWHO-TEQm(-3), and 94pgm(-3). Hence, BaP, and the other PAHs, showed the highest urban-background gradient (two orders of magnitude) and PCBs the lowest. The background pollution levels of BaP and PCDD/Fs were in agreement with the few available background/remote measurements in Europe. In Rome PAHs and PCBs, but not PCDD/Fs, were clearly seasonal; the PCDD/F TEQ was moderately correlated with BaP (P<0.001). At the background site, the seasonality of PAHs was less marked, while it could not be assessed for PCDD/Fs and PCBs. The PCB TEQ accounted for 4% and 15% of total (PCDD/Fs+PCBs) TEQ at the urban and background site, respectively. Mean PM(10) concentration was 54microgm(-3) in Rome and 15microgm(-3) at the background site.