Municipal waste management in Sicily: practices and challenges

There are numerous problems yet to be solved in waste management and although efforts towards waste recovery and recycling have been made, landfills are still the most common method used in the EU and many other industrialised countries. Thermal disposal, particularly incineration, is a tested and viable alternative. In 2004, only 11% of the annual waste production of Italy was incinerated. Sicily, with over five million inhabitants, is the second largest region in Italy where waste management is now a critical problem. The use of landfills can no longer be considered a satisfactory environmental solution; therefore, new methods have to be chosen and waste-to-energy plants could provide an answer. This paper gives details of municipal solid waste management in Sicily following a new Waste Management Plan. Four waste-to-energy plants will generate electricity through a steam cycle; the feedstock will become the residue after material recovery, which is calculated as 20-40% weight of the collected municipal solid waste.     

Validation of a European standard for the determination of hexavalent chromium in solid material

A European standard for the determination of Cr(vi) in solid material has been elaborated in the framework of an international co-operation and finally validated in the course of an interlaboratory comparison. The procedure is based on the alkaline digestion prescribed by EPA method 3060A followed by ion chromatography and determines an operationally defined content of Cr(vi), including water-soluble and insoluble chromates. A preliminary robustness study was carried out in order to compare different extraction methodologies and to study the equivalency of different analytical methods for the determination of Cr(vi) in alkaline extracts of soil and waste materials. During an interlaboratory validation trial with 19 European laboratories a set of 4 samples (2 soil and 2 waste samples) was analysed to determine performance characteristics for different combinations of digestion and detection methods. With the procedures prescribed by the new European standard (EN 15192) acceptable results were obtained for both soil samples and one of the waste samples (sludge). However, for the second waste sample (fly ash) a large deviation in analytical results was observed. This indicates that particularly for waste materials a possible occurrence of strong matrix effects has to be considered and supplementary quality control data are needed in order to assess the validity of analytical results. The accuracy of the determination of Cr(vi) in solid matrices remains a challenging field in terms of maximum extraction efficiency and minimum species interconversion.     

Aircraft Emissions: A Comparison of Methodologies Based on Different Data Availability

The impact of air traffic on the global atmosphere is characterised by a high degree of uncertainty, concerning both the physico-chemical phenomena involved and the extent of the forcing due to anthropogenic emissions. The different effects of these emissions (e.g. on climate change, stratospheric ozone depletion, acidification, tropospheric ozone formation) are dealt with by different international bodies and conventions (e.g. IPCC, EMEP. . .) which are trying to define a standard methodology allowing countries to evaluate their contributions to global aircraft emissions and to report these figures in a standardised way. The paper compares different methodologies proposed by the joint EMEP/CORINAIR 'Atmospheric Emission Inventory Guidebook' for estimating aircraft emissions. Adjustments to these methodologies have been proposed, in order to integrate some additional data such as the total amount of flight hours per aircraft type or fuel consumption per trip. In case detailed information is not available, we recommend the use of a VERY SIMPLE methodology which may yield acceptable results, provided that every country makes adequate assumptions on the average aircraft type.     

应对不确定性:呼吁建立新的科学政策论坛

科学界和政策界具有不同的目标,这就自然导致了对构成某种变化或现象的"检验"标准的差异,以及用不同的方法去描述不确定性和风险的持性及传达不确定性和风险.这些差异可能损害科学家、决策者和公众之间的有效沟通,同时也限制了科学家所愿意研究的社会紧迫问题的类型.本文主要回顾了一系列处理不确定性问题的方法,阐述了当科学和政策不能很好协调时所可能引起的一些错误.并在此基础上,特别针对解决不确定性问题提出了一些具体建议,包括重构科学规范,建立由科学、政策两方面领导广泛参加的科学政策论坛.     

Coping with uncertainty: a call for a new science-policy forum

The scientific and policy worlds have different goals, which can lead to different standards for what constitutes "proof" of a change or phenomena, and different approaches for characterizing and conveying uncertainty and risk. These differences can compromise effective communication among scientists, policymakers, and the public, and constrain the types of socially compelling questions scientists are willing to address. In this paper, we review a set of approaches for dealing with uncertainty, and illustrate some of the errors that arise when science and policy fail to coordinate correctly. We offer a set of recommendations, including restructuring of science curricula and establishment of science-policy forums populated by leaders in both arenas, and specifically constituted to address problems of uncertainty.     

Influence of Environmental Factors on the Evolution of Industrial Noise-Induced Hearing Loss

The aim of the study is to investigate how environmental factors, associated with exposure to industrial noise, affect the development of chronic noise-induced hearing loss.The studywas conducted on 186 male subjectsworking in two bottling plants, situated respectively in a small farming community, and in a medium-sized city with significant levels of noise pollution. Levels of occupational exposure were the same for the two groups.The subjects were selected by means of a preliminary medical examination, and exposed to tonal hearing tests and acoustic impedance tests. Statistical analysis was performed on hearing threshold values obtained at the frequencies of 500, 1000, 2000 and 4000 Hz.The comparison between the thresholds obtained in the two groups showed a statistically significant difference, especially at the frequency of 4000 Hz and for occupational exposure exceeding 17 yr. The results led us to conclude that environmental factors, and urban noise in particular, influence the onset and development of occupational acoustic trauma, and that those working in the country are significantly less affected than those in the city. Since occupational exposure was the same for both groups, their different responses must therefore be interpreted as due to differences in nonoccupational exposure, in turn dependent on different opportunities for rest from noise and different levels of exposure to noise pollution.