Investigation of simultaneous effects of noise barriers on near-road noise and air pollutants.

Noise barriers are one of the common solutions to control road traffic noise. Many studies have also shown that noise barriers cause reductions in near-road air pollutant concentrations. In this study, the simultaneous effects of a specific noise barrier application on near-road noise and air pollution at a specific location were investigated. In this context, air pollution, noise, and meteorological parameters were measured simultaneously at two points, road and receptor sides of a 50 m long, 4 m high glass fiber reinforced concrete noise barrier on a highway section. Results indicated that the noise barrier has an average 23 % reduction effect on the NOx concentration in addition to the noise level reduction at the receptor side. Besides, bi-weekly average passive sampler measurement results for BTEX pollutants indicate lower values at the receptor side of the barrier compared to the free field measurement results. In addition to real-time and passive sampler measurements, NOx and noise dispersions were modeled using RLINE and SoundPLAN 8.2 software, respectively. Comparisons of the measurement results with the model results indicated strong correlations. Model-calculated NOx and noise values under the free field conditions are highly compatible with a correlation coefficient (r) of 0.78. Although the noise barrier has a reduction effect on both parameters, it has been observed that their dispersion mechanisms are different. This study showed that noise barriers considerably affect the dispersion of road-sourced air pollutants at the receptor side. Further studies are needed to optimize noise barrier designs with different physical and material properties and application scenarios considering noise and air pollutants together.

Surface ozone levels in the forest and vegetation areas of the Biga Peninsula, Turkey.

Spatial and temporal variability of surface ozone in the rural, mountainous and suburban sites of Biga Peninsula, at the northwest of Turkey which is about 300km southwest of Istanbul was investigated using passive samplers and continuous analyzers. A total 10 passive samplers and two continuous analyzers were used between 1.1.2013 and 31.12.2014. OX levels in the study region were examined to understand NOx dependent or independent contribution to ozone. The influences of the meteorological parameters on ozone levels were also examined by wind speed and ambient temperature. The results clearly show that mountainous areas have higher cumulative exposure to ozone than suburban locations. In order to understand the long range transport sources contributing to the high ozone levels in the region backward trajectories were computed using HYSPLIT model and then clustering of trajectories are performed. The results clearly show the characteristics of pollutant transport from north to Biga Peninsula. Additionally, AOT40 (Accumulated hourly O3 concentrations Over a Threshold of 40ppb) cumulative index was calculated using daytime hourly measurements. The results indicate that the ozone values in the study area are much higher than the critical levels for forest and vegetation based on EU Directive 2008/50/EC.

Quantification of emissions from domestic heating in residential areas of Izmir, Turkey and assessment of the impact on local/regional air-quality.

Air pollution in cities is a major environmental problem principally in the developing countries. The quantification of emissions is a basic requirement to assess the human influence to the atmosphere. The air quality generally shows decreases with the major contribution residential emissions and meteorology in the winter season in the big cities. Poor meteorological conditions especially inversion events for the efficient mixing of air pollutants occurred during the winter months in Izmir. With this work we quantify the amount of domestic heating emissions for particulate matter (PM10), sulfur dioxides (SO2), nitrogen dioxides (NO2), volatile organic compounds (VOC) and carbon monoxide (CO) together with greenhouse gases which are carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) in Izmir for 2008-2009 winter season. The results showed that the most affected residential areas were central districts in the city center from domestic heating emissions due to meteorological condition and demographic reasons. Air quality modeling is a great tool for assisting policy makers how to decrease emissions and improve air quality. At the second part of the study, calculated emissions were modeled by using CALMET/CALPUFF dispersion modeling system and plotted in the form of air pollution maps by using geographical information system to determine the locations and estimate the effects of the new residential areas that will be established in the future in Izmir.

Measuring the levels of noise at the Istanbul Atatürk Airport and comparisons with model simulations.

Airport noise and its impact on the surrounding areas are major issues in the aviation industry. The Istanbul Atatürk Airport is a major global airport with passenger numbers increasing rapidly per annum. The noise levels for day, evening and night times were modeled around the Istanbul Atatürk Airport according to the European Noise Directive using the actual data records for the year 2011. The "ECAC Doc. 29-Interim" method was used for the computation of the aircraft traffic noise. In the setting the noise model for the local airport topography was taken into consideration together with the noise source data, the airport loadings, features of aircraft and actual air traffic data. Model results were compared with long-term noise measurement values for calibration. According to calibration results, classifications of the aircraft type and flight tracks were revised. For noise model validation, the daily noise measurements at four additional locations were used during the verification period. The input data was re-edited only for these periods and the model was validated. A successful model performance was obtained in several zones around the airport. The validated noise model of the Istanbul Atatürk Airport can be now utilized both for determining the noise levels in the future and for producing new strategies which are about the land use planning, operational considerations for the air traffic management and the noise abatement procedures.

Modeling of noise pollution and estimated human exposure around Istanbul Atatürk Airport in Turkey.

The level of aircraft noise exposure around Istanbul Atatürk Airport was calculated according to the European Noise Directive. These calculations were based on the actual flight data for each flight in the year 2011. The study area was selected to cover of 25km radius centered on the Aerodrome Reference Point of the airport. The geographical data around Istanbul Atatürk Airport was used to prepare elevation, residential building, auxiliary building, hospital and school layers in SoundPlan software. It was found that 1.2% of the land area of Istanbul City exceeds the threshold of 55dB(A) during daytime. However, when the exceedance of threshold of 65dB(A)is investigated, the affected area is found quite small (0.2% of land area of city). About 0.3% of the land area of Istanbul City has noise levels exceeding 55dB(A) during night-time. Our results show that about 4% of the resident population was exposed to 55dB(A) or higher noises during daytime in Istanbul. When applying the second threshhold criteria, nearly 1% of the population is exposed to noise levels greater than 65dB(A). At night-time, 1.3% of the population is exposed to 55dB(A) or higher noise levels.

Evaluation of the impact of SO2 and NO2 emissions on the ambient air-quality in the Çan-Bayramiç region of northwest Turkey during 2007-2008.

The characterization and assessment of air-quality in this region are essential steps for the implementation of the "Clean Air Action Plan" as this is set by the Turkish Regulation on Ambient Air-Quality Assessment and Management. This study area intends to shed a light on use of modeling tools as an alternative method for the assessment of local atmospheric pollution and the determination of the importance of local emissions. This modeling approach can be also used for the consistent geographic representation of air-quality concentration as well as for assessing the future air-quality condition after the implementation of emission reduction measures in a certain area. With this article we evaluate the impact of sulfur dioxide and nitrogen dioxide emissions on the ambient air-quality in the Çan-Bayramiç region of Turkey. The emission rates of sulfur dioxide and nitrogen dioxide were calculated by using the CALPUFF model. The concentration of these pollutants had also been monitored at ten air-quality locations during 2007-2008 in the research area. The measured data were also utilized for testing the model performance. Results showed that the air-quality in this important rural region of Turkey can be evaluated effectively by using the current numerical modeling system.