Air Quality in a Dental Clinic during Er:YAG Laser Usage for Cavity Preparation on Human Teeth-An Ex-Vivo Study.

Chemical air pollution in dental clinics consists of the emission of gases and particulate matter (PM), both generated by dental equipment and tooth tissues. One basic application of Erbium Laser devices is cavity preparation on human teeth due to its strong affinity to water and hydroxyapatite. The objective of this study was the evaluation of indoor air quality during the application of an Er:YAG laser, as a dentin removal instrument, in a Dental Clinic.

Immediate effects of retinoic acid on gene expression in primary murine osteoblasts.

Consistent with clinical observations demonstrating that hypervitaminosis A is associated with increased skeletal fracture risk, we have previously found that dietary retinol deprivation partially corrects the bone mineralization defects in a mouse model of X-linked hypophosphatemic rickets. That retinol-dependent signaling pathways impact the skeleton is further supported by various findings demonstrating a negative influence of retinoic acid (RA) on bone-forming osteoblasts. We hypothesized that RA would directly regulate the expression of specific target genes in osteoblasts, and we aimed to identify these by genome-wide expression analyses.

An integrated evaluation study of the ventilation rate, the exposure and the indoor air quality in naturally ventilated classrooms in the Mediterranean region during spring.

Ventilation rates and indoor air pollutants have been extensively monitored in nine naturally ventilated primary schools of Athens, Greece during spring. The ventilation rates and pollutant levels were studied during the teaching and non-teaching periods and ventilation profiles were created for each of the schools. The median ventilation rates per school ranged between 0.

Flux measurements in the surface Marine Atmospheric Boundary Layer over the Aegean Sea, Greece.

Micro-meteorological measurements within the surface Marine Atmospheric Boundary Layer took place at the shoreline of two islands at northern and south-eastern Aegean Sea of Greece. The primary goal of these experimental campaigns was to study the momentum, heat and humidity fluxes over this part of the north-eastern Mediterranean Sea, characterized by limited spatial and temporal scales which could affect these exchanges at the air-sea interface. The great majority of the obtained records from both sites gave higher values up to factor of two, compared with the estimations from the most widely used parametric formulas that came mostly from measurements over open seas and oceans.

Malignant H1299 tumour cells preferentially internalize iron-bound inositol hexakisphosphate.

In colon enterocytes and in well-differentiated colon cancer CaCo-2 cells, InsP6 (inositol hexakisphosphate) inhibits iron uptake by forming extracellular insoluble iron/InsP6 complexes. In this study, we confirmed that CaCo-2 cells are not able to take up iron/InsP6 but, interestingly, found that the cells are able to internalize metal-free and Cr3+-bound InsP6. Thus, the inability of CaCo-2 cells to take up iron/InsP6 complexes seems to be due to the iron-bound state of InsP6.

Determining the ventilation and aerosol deposition rates from routine indoor-air measurements.

Measurement of air exchange rate provides critical information in energy and indoor-air quality studies. Continuous measurement of ventilation rates is a rather costly exercise and requires specific instrumentation. In this work, an alternative methodology is proposed and tested, where the air exchange rate is calculated by utilizing indoor and outdoor routine measurements of a common pollutant such as SO2, whereas the uncertainties induced in the calculations are analytically determined.

Issues related to aircraft take-off plumes in a mesoscale photochemical model.

The physical and chemical characteristics of aircraft plumes at the take-off phase are simulated with the mesoscale CAMx model using the individual plume segment approach, in a highly resolved domain, covering the Athens International Airport. Emission indices during take-off measured at the Athens International Airport are incorporated. Model predictions are compared with in situ point and path-averaged observations (NO, NO₂) downwind of the runway at the ground.

Quantification of environmental tobacco smoke contribution on outdoor particulate aliphatic and polycyclic aromatic hydrocarbons.

The objective of this study was to identify and quantify the sources of fine particulate aliphatic and polycyclic aromatic hydrocarbons (PAHs) in an urban area in southeastern Europe. A total of 91 urban PM2.5 samples were analyzed by gas chromatography coupled with mass spectrometry for alkanes and PAHs.

PM1 and PM2.5 ionic composition and VOCs measurements in two typical apartments in Athens, Greece: investigation of smoking contribution to indoor air concentrations.

During the last decades, the air quality of the city of Athens has been quite aggravated. Scientific interest has been focused on health effects caused by both outdoor and indoor air pollution. The purpose of this study was the presentation of results from air quality measurements in two similar typical Athenian apartments in the same suburban area.

Temporal evolution of the main processes that control indoor pollution in an office microenvironment: a case study.

The aim of this study is to examine the relative contribution of the outdoor concentration, the ventilation rate, the geometric characteristics of the indoor environment (i.e., extent of indoor surfaces and indoor volume), the deposition, and chemical reactions to the indoor air quality of the office microenvironment.

Emissions of total volatile organic compounds and indoor environment assessment in dental clinics in Athens, Greece.

Objective: To quantify the amount of Total Volatile Organic Compounds (TVOCs) emitted from five dental substances commonly used in a dental clinic.

Method: An assessment of the indoor air quality in two clinics of the Athens University Dentistry Faculty was conducted.

Results: It was found that TVOC emissions from Kalocryl and Bacillol reached extremely high values affecting the air in the dental clinics at short and long distances from the source.

PM2.5 and volatile organic compounds (VOCs) in ambient air: a focus on the effect of meteorology.

PM(2.5) and VOCs (benzene, toluene, m-p-o-xylenes) concentrations were measured in an urban and a suburban site in Athens, Greece, during the period between April and November 2004. This period, which is considered to be the warmer period in Greece, is characterized by the development of sea-breeze over the Attica Basin.

Indoor air quality assessment in the air traffic control tower of the Athens Airport, Greece.

In this study, an assessment of indoor air quality (IAQ) and thermal comfort in the Athens Traffic Control Tower (ATCT) offices of Hellinicon building complex, which is mechanically ventilated, is presented. Measurements of PM(10), PM(2.5), TVOCs and CO(2) concentrations were performed during three experimental cycles, while the Thom Discomfort Index was calculated to describe the employees' feeling of discomfort.

On the estimation of characteristic indoor air quality parameters using analytical and numerical methods.

Indoor exposure to air contaminants penetrating from the outdoor environment depends on a number of key processes and parameters such as the ventilation rate, the geometric characteristics of the indoor environment, the outdoor concentration and the indoor removal mechanisms. In this study two alternative methods are used, an analytical and a numerical one, in order to study the time lag and the reduction of the variances of the indoor concentrations, and to estimate the deposition rate of the air contaminants in the indoor environment employing both indoor and outdoor measurements of air contaminants. The analytical method is based on a solution of the mass balance equation involving an outdoor concentration pulse which varies sinusoidally with the time, while the numerical method involves the application of the MIAQ indoor air quality model assuming a triangular pulse.

Indoor air quality in a dentistry clinic.

The purpose of this work is to assess, both experimentally and theoretically the status of air quality in a dentistry clinic of the Athens University Dentistry Faculty with respect to chemical pollutants and identify the indoor sources associated with dental activities. Total VOCs, CO(2), PM(10), PM(2.5), NO(x) and SO(2) were measured over a period of approximately three months in a selected dentistry clinic.

Lung deposition of fine and ultrafine particles outdoors and indoors during a cooking event and a no activity period.

Unlabelled: Some indoor activities increase the number concentration of small particles and, hence, enhance the dose delivered to the lungs. The received particle dose indoors may exceed noticeably the dose from ambient air under routine in-house activities like cooking. In the present work, the internal dose by inhalation of ultrafine and fine particles is assessed, using an appropriate mechanistic model of lung deposition, accommodating aerosol, and inhalation dynamics.

Gas-particle concentration and characterization of sources of PAHs in the atmosphere of a suburban area in Athens, Greece.

Atmospheric polycyclic aromatic hydrocarbons (PAH) were determined in two places in a suburban area of Athens greater area (AGA) during June and November 2003. Fourteen PAHs were quantified in the collected samples. The total concentration in the gas phase ranged between 6.

An experimental study of aerosol distribution over a Mediterranean urban area.

In this study an attempt is made to investigate the aerosol spatial and size distributions at different heights over the Greater Athens Area (GAA), Greece, under sea breeze conditions and clear sky and to further discuss possible implications for aerosol characteristics. The data used are airborne measurements of aerosol collected during two flights that were performed within the context of the 1997 STAAARTE experimental campaign. The aerosol measurements cover particle diameters from 0.

Temporal variations of PM2.5 in the ambient air of a suburban site in Athens, Greece.

Twenty-three hour measurements of PM(2.5) particulate matter have been carried out during the period between the 1st April and the 13th November 2003 in a suburban area of Athens. The monitoring site was located in the National Research Center "DEMOKRITOS", on the foot of Hemittos Mountain and about 12 km away from the center of Athens.

Investigating cigarette-smoke indoor pollution in a controlled environment.

The objective of this study was to investigate the evolution of pollutant concentrations generated by smoking in a controlled indoor environment. For this purpose, a small flat in the centre of Athens, Greece was equipped with NO(x), O(3) and SO(2) continuous measuring instruments and portable analysers for spot measurements of TVOCs and CO(2), while two volunteer smokers remained inside and smoked as normal inhabitants. The results indicated that when windows are kept closed and smoking takes place NO(x), CO(2) and TVOCs concentrations increase by an order of 3, 4 or 10 times, respectively, and decrease returning to initial levels after 1 or 2 h.

Sodar mixing height estimates and air pollution characteristics over a Mediterranean big city.

Sodar systems are progressively used for quantitative and qualitative profile information on the atmospheric structure parameters. However, there is still a need for well-established relations between atmospheric physics parameters and air quality patterns, especially in urban environments. In this respect it is of importance to investigate the correlations among specific atmospheric quantities and air pollution patterns.