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The indoor O3, NO, NO2 concentrations and their corresponding indoor/outdoor (I/O) concentration ratios are predicted in this paper for some representative buildings, using the Nazaroff-Cass indoor air quality model. This paper presents and systemizes the relationship between indoor air pollutant concentrations and the buildings design, use and operation. The building parameters which aredetermined to be main factors affecting the air pollutant concentrations are: the physical dimensions of the building and the materials of construction, the building's air exchange rate with outdoors and the indoor air pollutant sources. Changes of ultraviolet photon fluxes,of temperature and of relative humidity indoors, have little effect on indoor O3, NO and NO2 concentrations, for air exchange rates above 0.5 ach. Special attention must be given when a building has a very low air exchange rate, under which conditions the effect of a small change in any of the factors determining the indoor air quality of the building will be much more noticeable than in a building with a high air exchange rate. [ABSTRACT FROM AUTHOR]

Statement of Problem: Daily disinfection of maxillofacial prosthesis may reduce their service-life and lead to replacement., Purpose: The purpose of this study was to evaluate possible alterations in the mechanical behavior of two maxillofacial elastomers after application of four different disinfection procedures., Material and Methods: The materials tested were two maxillofacial elastomers, a commercially available polydimethylsiloxane (PDMS) and an experimental chlorinated polyethylene (CPE). Different disinfection procedures such as microwave exposure, hypochlorite solution, neutral soap and a commercially antimicrobial solution, were applied for a period which simulates one year of a real service life. Mechanical behavior was investigated through tensile and microindentation tests in various depths. Mathematical models were fitted to tensile curves. Alterations in tensile parameters (maximum stress, maximum strain, elasticity and viscoelasticity parameter) were subjected to two way ANOVA and Tukey's post hoc tests (α=.05)., Results: Most of the tensile parameters presented significant alterations among different disinfection procedures and maxillofacial materials which became also harder. Microwave exposure caused greater changes in PDMS and CPE elastomer whereas commercial antimicrobial solution and neutral soap did not significantly affect them. Microindentation and tensile tests revealed similar changes in materials' elastic modulus and hardness whereas the observed changes were greater into smaller depths., Conclusions: Tensile and microindentation properties of PDMS and CPE elastomers presented changes after disinfected with four different procedures. Changes in the surface of both materials were more intense than in the bulk of the materials. Microwave exposure affected most the two elastomers, so concerning the findings of this study is not recommended for the disinfection of the examined PDMS and CPE elastomers. Moreover, microwave exposure and hypochlorite solution caused greater changes in the surface (3μm) of CPE samples as indicated by microindentation results. PDMS affected less from the commercial antimicrobial agent and CPE from neutral soap, which seems to be the most suitable disinfection techniques., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Land-use planning, as concerns the prevention and limitation of the consequences of possible major accidents from industrial installations, is an essential mechanism for dealing with actual or potential conflicts between sources of risk, such as potentially hazardous industrial developments, and surrounding land-uses. The objective of this paper is to present a decision making methodology that is suitable for assisting urban and spatial planning in the vicinity of hazardous installations and therefore covers the directions of Article 12 of the European Council Directive 96/82/EC (the so-called SEVESO II directive). The proposed methodology was designed to address the particularities of the Greek case, regarding the type and availability of risk and spatial data. It incorporates a broad set of multiple and conflicting criteria that arise in land-use planning decisions, through the application of a well known multi-criteria decision analysis method (ELECTRE TRI). Additionally, it is easy to use (comprised of simple steps) and can be readily incorporated into Geographical Information System based platforms., (2010 Elsevier B.V. All rights reserved.)

Background: It is not known whether working in surface lignite mines can cause x-ray lesions or disorders of respiratory function., Objectives: The aim of the study was to investigate the diachronic impact of environmental pollution on the respiratory system of lignite miners at mines in Eordea, Greece., Methods: Cases of 199 workers (Group A) residing permanently in the Eordea valley and 151 (Group B) living outside the Eordea valley were studied during Phase I and then re-examined after three years (Phase II). These cases were compared to those of 71 office workers living in Eordea valley (Group C) and to 96 living in Grevena, a region without pollution (Group D). The study included the completion of the MRC questionnaire for the detection of respiratory diseases, pulmonary function tests, measurement of diffusion capacity, otorhinolaryngologic examination, rhinomanonetry as well as chest and paranasal cavity X-rays., Results: Chronic bronchitis was reported by 26.8%, 24.8%, 17.9% and 10.6% respectively of the subjects of groups A, B, C and D according to the answers of the questionnaire (p<0.001). The spirometry and diffusion capacity findings presented no considerable differences either in the 4 groups or between phases I and II of the study. The main problems were detected in the upper airways. A very high prevalence of severe nasal obstruction (73%, 71.2%, 55.7% and 19.3% in Groups A, B, C and D respectively) was detected. Furthermore, a high percentage of atrophic rhinitis (14%) was detected both among workers (Groups A and B) and subjects living in the Eordea valley who participated as controls (Group C). From the X-rays, hypertrophy of nasal turbinates-cartilage and polyposis was observed as follows: Group A: 53.9%, Group B: 48.1%, Group C: 46.5% and Group D: 20.3% (p<0.001). The findings related to the upper respiratory system may be due to excessive pollution by airborne particles (fly ash) pollution in the region and particularly to chromium, nickel, cobalt and lead found at high concentration levels in airborne dust. A marked association between the total air-flow in the nose and the mid-expiratory flow (p<0.01) was detected., Conclusions: We conclude that subjects working in lignite mines under conditions of excessive pollution by airborne contaminants have a high prevalence of atrophic rhinitis and, in addition to other standard examinations, should undergo rhinomanometry testing and X-ray imaging of the paranasal cavities.

In this paper, an attempt is made for the 24-hr prediction of photochemical pollutant levels using a neural network model. For this purpose, a model is developed that relates peak pollutant concentrations to meteorological and emission variables and indexes. The analysis is based on measurements of O3 and NO2 from the city of Athens. The meteorological variables are selected to cover atmospheric processes that determine the fate of the airborne pollutants while special care is taken to ensure the availability of the required input data from routine observations or forecasts. The comparison between model predictions and actual observations shows a good agreement. In addition, a series of sensitivity tests is performed in order to evaluate the sensitivity of the model to the uncertainty in meteorological variables. Model forecasts are generally rather insensitive to small perturbations in most of the input meteorological data, while they are relatively more sensitive in changes in wind speed and direction.

Detailed knowledge of the quantity and composition of urban emissions is a prerequisite for successful application of atmospheric models to predict transport and distribution of primary and secondary air pollutants in the troposphere. We investigate the prospects and limitations of aircraft measurements in the determination of emission fluxes from urban areas. Our analysis focuses on data collected in September 1994 in and around Athens, Greece. Generally, emission fluxes from cities can be quantified with aircraft and with the minimum acceptable precision (uncertainty better than a factor of 2) only under very favorable meteorological conditions, namely in a homogeneous flow field in a well-mixed boundary layer. Better accuracy can be achieved only through ensemble averaging of repeated measurements. From our measurements in the Athens area, we deduced relative emission ratios of pollutant gases. With the support of ground-based measurements in a street canyon, the emission ratios NOx/CO, SO2/CO, and volatile organic compounds/CO (34 individual VOCs) could be determined with high precision. These results are very useful in analyzing differences between various existing emission inventories. Our data for VOCs reveal that the non-traffic emissions are of the same magnitude as the emissions originating from traffic.