Air quality impact assessment for the Eurasia Tunnel in Istanbul, Turkey.

The Eurasia Tunnel, a 5.4-km tunnel connecting the Asian and European sides of Istanbul, Turkey, was opened for operation in December 2016. This paper describes the air quality modeling that was conducted during the design phase of the structure, to evaluate the impact of the tunnel traffic on ambient air quality in the vicinity of the tunnel. The ventilation of the tunnel consists of longitudinal forced ventilation with vertical extraction through two stacks located near the Asian and European portals of the tunnel. The analysis was conducted using the AERMOD computer program for three pollutants CO, NO2, and PM10. Model results show that pollutants will rapidly disperse once released from the stack and will not affect air quality in the vicinity of the tunnel. The most critical parameters which controlled the ventilation system design were found to be NO2 and PM10. Maximum concentrations are not expected to violate the pertinent Turkish and EU air quality standards. Overall, this analysis shows that the ventilation system is efficient for the dispersion of the pollutants.

Impact of deforestation on soil carbon stock and its spatial distribution in the Western Black Sea Region of Turkey.

Land use management is one of the most critical factors influencing soil carbon storage and the global carbon cycle. This study evaluates the impact of land use change on the soil carbon stock in the Karasu region of Turkey which in the last two decades has undergone substantial deforestation to expand hazelnut plantations. Analysis of seasonal soil data indicated that the carbon content decreased rapidly with depth for both land uses. Statistical analyses indicated that the difference between the surface carbon stock (defined over 0-5 cm depth) in agricultural and forested areas is statistically significant (Agricultural = 1.74 kg/m(2), Forested = 2.09 kg/m(2), p = 0.014). On the other hand, the average carbon stocks estimated over the 0-1 m depth were 12.36 and 12.12 kg/m(2) in forested and agricultural soils, respectively. The carbon stock (defined over 1 m depth) in the two land uses were not significantly different which is attributed in part to the negative correlation between carbon stock and bulk density (-0.353, p < 0.01). The soil carbon stock over the entire study area was mapped using a conditional kriging approach which jointly uses the collected soil carbon data and satellite-based land use images. Based on the kriging map, the spatially soil carbon stock (0-1 m dept) ranged about 2 kg/m(2) in highly developed areas to more than 23 kg/m(2) in intensively cultivated areas as well as the averaged soil carbon stock (0-1 m depth) was estimated as 10.4 kg/m(2).

The impact of hazelnuts in land-use changes on soil carbon and in situ soil respiration dynamics.

Our study assessed the impact of hazelnuts (Coryllus avellena L.) in land-use conversion from forest (F) to agricultural land (AL) on various attributes of soil respiration dynamics, such as soil elemental carbon (C%) content, microbial respiration, bulk density, soil pH, electrical conductivity, and seasonal variations. We developed soil C% models to compare soil C% between F and AL soils. Four field trips were conducted in the winter and summer of 2008 and the spring and fall of 2009 in the Karasu region of Turkey. During each trip, 42 sites were visited F (n = 21) and AL (n = 21). Our results showed that hazelnuts plantations in AL could reduce elemental C% by 27% (winter 2008), 16% (summer 2008), 41% (spring 2009), and 22% (fall 2009) in the four seasons studied when compared to F soils. In situ soil respiration was also reduced by 31% (spring 2008), 67% (fall 2008), 88% (spring 2009), and 79% (fall 2009) in AL soils over F soils. The percent of organic matter of AL soils was declined by 36% (winter 2008), 23% (summer 2008), 34% (spring 2009), and 26% (fall 2009) in comparison to F soils. Significant reductions in the correlation between C%-percent clay and C%-electrical conductivity were also recorded for AL soils over F soils. Furthermore, AL soils showed higher bulk density (7.4% and 7%) when compared to F soils. We also found that in situ soil respiration had significant seasonal correlations (p < 0.05) with soil pH (0.537), soil temperature, and percent clay (-0.486) in F soils (summer 2008, spring 2009). Additionally, we found that seasonal variations of four sampling seasons had a moderate impact on in situ respiration and that the differences were statistically significant, except for the winter-summer and spring-fall seasonal pairs. Linear regression C models showed significant differences for F and AL soils.

Recovery of biogas as a source of renewable energy from ice-cream production residues and wastewater.

Proper management of waste streams and residues from agro-industry is very important to prevent environmental pollution. In particular, the anaerobic co-digestion process can be used as an important tool for safe disposal and energy recovery from agro-industry waste streams and residues. The primary objective of this laboratory-scale study was to determine whether it was possible to recover energy (biogas) from ice-cream production residues and wastewater, through a mesophilic anaerobic co-digestion process. A high methane yield of 0.338 L CH4/gCOD(removed) could be achieved from anaerobic digestion of ice-cream wastewater alone, with almost 70% of methane in biogas, while anaerobic digestion of ice-cream production residue alone did not seem feasible. When wastewater and ice-cream production residue were anaerobically co-digested at a ratio of 9:1 by weight, the highest methane yield of 0.131 L CH4/gCOD(removed) was observed. Buffering capacity seemed to be imperative in energy recovery from these substrates in the anaerobic digestion process.

Impacts of coal-fired power plants for energy generation on environment and future implications of energy policy for Turkey.

Turkish government aimed to increase the installed capacities of coal-fired power plants (CFPPs) according to several policies and strategic plans published in recent years. Energy production from CFPPs and subsidizing the coal sector were selected for reducing the import dependency as a cheaper option. CFPPs with gaseous emissions as well as fly ash and fine dust, along with ash storage, coal storage, and coal mining operations and water use for cooling of the plants, affect the environmental quality. Hence, the health of inhabitants of the environment is affected. CFPPs to be built, according to strategic plans, will emit a significant amount of greenhouse gases (GHGs) and would severely undermine the targets for a 1.5 ℃ or 2 ℃ warmer world. Subsidies to the coal sector, along with exemptions from environmental regulations, combined with slower growth of energy production from renewable energy sources (RES), may lead to a path dependence on coal, while the rest of the world increases their energy production from RES. This study demonstrates the concrete examples of pollution caused by CFPPs in Turkey, along with health effects with the addition of policy context toward utilization of CFPPs, to point out the risks these plants constitute both for the environment and economy. Increasing the share of RES in the energy mixture is particularly important for Turkey due to being in a geographical region that is highly vulnerable to climate change effects. This study also briefly discusses how the increase of RES and de-carbonization in Turkey could be conducted in the short- and long-term, upon the literature provided.

Evaluation of microplastics removal efficiency at a wastewater treatment plant discharging to the Sea of Marmara.

Levels, composition and fate of microplastics (MPs) were investigated along different compartments of a secondary wastewater treatment plant (WWTP) with nutrient removal on the northern Sea of Marmara coast (Istanbul, Turkey). When all samples were combined, fibers were found to be the most dominant particles, followed by hard fragments. 500-1000 µm and 1000-2000 µm were the most common size ranges for wastewater and sludge, respectively. Rate of removal differed for sizes and shapes of the particles combined. Hard fragments of <500 µm and fibers of size ranges 250-500 µm and 1000-2000 µm were more successfully removed within the WWTP. Size averages increased throughout the WWTP units. 84.6-93.0% removal was achieved for grab and 3-hr composite samples. Despite the high removal rates of the WWTP, 2,934 × 106 microplastic particles/d were released in the effluent to the Sea of Marmara. Our results show that the Ambarli WWTP considerably contributes to microplastics contamination in the Sea of Marmara since the plant has a high operating capacity.

Impact of overland traffic on heavy metal levels in highway dust and soils of Istanbul, Turkey.

The purpose of this study was to investigate the impact of overland traffic on the spatial distribution of heavy metals in urban soils (Istanbul, Turkey). Road dust, surface, and subsurface soil samples were collected from a total of 41 locations along highways with dense traffic and secondary roads with lower traffic and analyzed for lead (Pb), zinc (Zn), and copper (Cu) concentrations. Statistical evaluation of the heavy metal concentrations observed along highways and along the secondary roads showed that the data were bimodally distributed. The maximum observed Pb, Zn, and Cu concentrations were 1,573, 522 and 136 mg/kg, respectively, in surface soils along highways and 99.3, 156, and 38.1 mg/kg along secondary roads. Correlation analysis of the metal concentrations in road dust, surface and 20-cm depth soils suggests the presence of a common pollution source. However, metal concentrations in the deeper soils were substantially lower than those observed at the surface, indicating low mobility of heavy metals, especially for Pb and Zn. A modified kriging approach that honors the bimodality of the data was used to estimate the spatial distribution of the surface concentrations of metals, and to identify hotspots. Results indicate that despite the presence of some industrial zones within the study area, traffic is the main heavy metal pollution source.

Impact of food waste fraction in municipal solid waste on sorption of heavy metals.

The presence of organic materials plays an important role in the fate of heavy metals that are co-disposed together with municipal solid wastes. As a part of an on-going research project, which aims to find out the most effective attenuation mechanism of heavy metal removal in landfills, sorption batch experiments were performed to assess the sorption behaviour of iron, copper, nickel and zinc on synthetic solid wastes containing 76% (W1) and 45% (W2) food waste percentages and waste-to-solution ratios ranging from 1:4 to 1:16. The analysis of sorption data suggested that the data fit a Freundlich equilibrium isotherm. The time required for reaching equilibrium conditions varied for each metal investigated, but all generally reached equilibrium conditions within 7 h. For both solid waste compositions, metal sorption increased with increase in waste-to-solution ratio, with the order of metal removal percentages consistently found to be Zn > Ni > Cu > Fe. The results also show that a large fraction of the heavy metals could be attenuated by sorption on the solid waste. The removal percentages for Zn and Ni were slightly higher for W2, whereas the removal percentages for Fe and Cu were approximately equal for both waste types. Overall, this study demonstrates that sorption is a viable process that can mitigate the potential adverse impacts of landfill leachate.

Exterior air quality monitoring for the Eurasia Tunnel in Istanbul, Turkey.

Traffic is a major concern for the city of Istanbul due to the rapid increase in population and car ownership. Eurasia Tunnel, which has a capacity around 100,000 light vehicles/day, is the fourth highway link between Asia and Europe, established to relieve the existing pressure on the transport system. As an important alternative to other Bosphorus Strait crossings, the tunnel offers directly reduced traffic durations in the city especially during rush hours and indirectly provides reduced fuel consumption, thereby less harmful gas emissions into the atmosphere. The main objective of this study is to evaluate the air quality effects of the Eurasia Tunnel on the city of Istanbul through investigating the air quality 1 year before and 2 years after operation, and comparing the hourly and daily pollutant levels with tunnel traffic. Monitoring data were examined to detect the relationships between selected pollutant concentrations, to evaluate meteorology effects on the pollutants and to identify air quality impact of the Eurasia Tunnel. Analyses revealed that air pollutants concentrations do not increase with increase in tunnel traffic. Moreover, since the tunnel entered operation, average hourly CO, PM10 and PM2.5 concentrations at monitoring stations located close to the stacks have decreased 16-30%, 44-46% and 12-24%, respectively. Average NO2 concentrations increased about 9-24%, but these concentrations still remain below the 1-hour standard. All in all, Eurasia Tunnel has no significant effect on the Istanbul's air quality.

Comparison of aerobic and anaerobic degradation of municipal solid waste in bioreactor landfills.

Two landfill bioreactors were operated under aerobic and anaerobic conditions in a thermo-insulated room at a constant temperature of 32 degrees C. Reactors were filled with 19.5 kg of shredded synthetic solid waste prepared according to the average municipal solid waste compositions determined in Istanbul and operated under wet-tomb management strategy by using leachate recirculation. Aerobic conditions in the reactor were developed by using an air compressor. The results of experiments indicated that aerobic reactor had higher organic, nitrogen, phosphorus and alkali metal removal efficiencies than the anaerobic one. Furthermore, stabilization time considerably decreased when using aerobic processes with leachate recirculation compared to the anaerobic system with the same recirculation scheme.

Biodegradation of bioplastics in natural environments.

The extensive production of conventional plastics and their use in different commercial applications poses a significant threat to both the fossil fuels sources and the environment. Alternatives called bioplastics evolved during development of renewable resources. Utilizing renewable resources like agricultural wastes (instead of petroleum sources) and their biodegradability in different environments enabled these polymers to be more easily acceptable than the conventional plastics. The biodegradability of bioplastics is highly affected by their physical and chemical structure. On the other hand, the environment in which they are located, plays a crucial role in their biodegradation. This review highlights the recent findings attributed to the biodegradation of bioplastics in various environments, environmental conditions, degree of biodegradation, including the identified bioplastic-degrading microorganisms from different microbial communities.

Effect of nano-ZnO on biogas generation from simulated landfills.

Extensive use of nanomaterials in commercial consumer products and industrial applications eventually leads to their release to the waste streams and the environment. Nano-ZnO is one of the most widely-used nanomaterials (NMs) due to its unique properties. It is also known to impact biological processes adversely. In this study, the effect of nano-ZnO on biogas generation from sanitary landfills was investigated. Two conventional and two bioreactor landfills were operated using real MSW samples at mesophilic temperature (35°C) for a period of about 1year. 100mg nano-ZnO/kg of dry waste was added to the simulated landfill reactors. Daily gas production, gas composition and leachate Zn concentrations were regularly monitored. A model describing the fate of the nano-ZnO was also developed. The results obtained indicated that as much as 99% of the nano-ZnO was retained within the waste matrix for both reactor operation modes. Waste stabilization was faster in simulated landfill bioreactors with and without the addition of nano-ZnO. Moreover, the presence of the nano-ZnO within the waste led to a decrease in biogas production of about 15%, suggesting that the nano-ZnO might have some inhibitory effects on waste stabilization. This reduction can have potentially significant implications on waste stabilization and the use of biogas from landfills as a renewable energy source.

Determination of solid waste sorption capacity for selected heavy metals in landfills.

The adsorption process is largely a surface-action phenomenon. In this study, sorption capacities for heavy metals on a solid waste matrix were investigated. Five heavy metals (iron, copper, zinc, nickel and cadmium) were chosen because of their availability in any landfill site. The conditions during all the experimental runs were pH 7.0, temperature 32 degrees C and suppressed microbial degradation. For adsorption isotherm (Freundlich and Langmuir) calculations, fixed quantities of heavy metal ions were mixed with variable quantities of solid waste. The ratio of mass of adsorbate per unit mass of adsorbent was changed five times, by changing only the adsorbent amount. The results showed that the time required to reach equilibrium varied from metal to metal but all reached equilibrium within the first 32 h. The relative potential of sorption of the individual metals and mixed metals on the solid waste matrix is Fe > Zn > Cu > Ni > Cd. The sorption capacity of domestic solid waste matrix for heavy metals is quite significant and this property might prove helpful for the in situ removal of heavy metals in landfill operation.

Effect of combined aspirin and angiotensin-converting enzyme inhibitor therapy versus angiotensin-converting enzyme inhibitor therapy alone on readmission rates in heart failure.

An adverse interaction between aspirin and angiotensin-converting enzyme (ACE) inhibitors is suspected in patients with heart failure, but the effect of combined therapy with these agents on hospital readmission rates is unknown. Our study found that combining aspirin with ACE inhibitors is associated with higher early readmission rates than use of ACE inhibitors alone, particularly in patients with depressed ejection fraction and in those without coronary artery disease.

Simple clinical variables are markers of the propensity for readmission in patients hospitalized with heart failure.

In a consecutive cohort of patients hospitalized for decompensated heart failure, we found that chronic obstructive pulmonary disease and history of hospitalization for any cause in the preceding 6 months were the strongest correlates of early readmission. Based on these findings, we propose a simple risk stratification system to classify patients who are hospitalized for heart failure as low, medium, or high risk for early readmission.

Effects of caregiver specialty on cost and clinical outcomes following hospitalization for heart failure.

In 614 consecutive hospitalizations with the primary discharge diagnosis of diagnosis-related group (DRG) 127 (heart failure and shock), we sought to assess the effect of caregiver specialty (generalist, n = 217; cardiologist, n = 397) on hospital costs, length of stay, and in-hospital mortality. Patients treated by cardiologists were younger (68 vs 71 years) and less likely to have hypertension (52% vs 61%), but were more likely to be men (61% vs 44%), require an intensive care stay (13% vs 5%), have coronary artery disease (49% vs 23%), have a left ventricular ejection fraction <40% (74% vs 49%), and have lower systolic (132 vs 146 mm Hg) and diastolic (76 vs 81 mm Hg) blood pressures on admission. Predictors of acute disease severity were similarly distributed between the 2 groups. No difference was found between patients treated by cardiologists versus those treated by generalists with respect to crude or adjusted hospital cost, length of stay, and in-hospital mortality. However, in subsets of patients who required intensive care during hospitalization (n = 64), as well as those who did not (n = 550), care by cardiologists was associated with a lower adjusted hospital cost. Any potential cost savings that could have accrued from care by cardiologists was, however, negated by the higher proportion of patients treated by cardiologists who required intensive care during hospitalization. We conclude that when differences in clinical variables are adjusted, care by cardiologists versus generalists is associated with similar or lower hospital cost for patients with DRG 127. Our findings challenge the notion that in-patient care provided by specialists is more expensive than that provided by generalists.

Does gender bias exist in the medical management of heart failure?

INTRODUCTION: The purpose of this study was to ascertain the presence of gender bias in the medical management of heart failure, and to assess its association with the specialty of the caregiver physician. METHODS: In 309 patients with documented left ventricular systolic dysfunction (ejection fraction <45%) and at least one hospitalization for heart failure, we assessed the frequency of use of effective medical therapy for heart failure among male (n=187) and female (n=122) patients at the time of hospital discharge. We constructed multivariate models relating patient gender and caregiver specialty to utilization of each class of medications (angiotensin-converting enzyme inhibitors, effective vasodilator therapy (i.e., angiotensin-converting enzyme inhibitors or hydralazine-nitrate therapy), diuretics, digoxin), and combination therapy (i.e., vasodilator plus diuretic plus digoxin). RESULTS: In crude analyses, we did not find any difference in utilization of medications between male and female patients. Multivariate analyses involving adjustment for age, race, coronary artery disease, ejection fraction, and other relevant variables, revealed higher utilization of combination therapy by cardiologists in male versus female patients (adjusted odds ratios=2.07; 95%CI=1.09-3.95), and higher utilization of digoxin therapy by non-cardiologists in female versus male patients (adjusted odds ratio=5.5; 95%CI=1.4-22.2). No gender or caregiver specialty differences were seen in models relating to the other classes of medications. CONCLUSIONS: Our findings suggest the presence of gender bias in the medical management of heart failure, and identify an interesting interaction between caregiver specialty and gender bias.

The prognostic implications of outpatient diuretic dose in heart failure.

In 111 patients with left ventricular ejection fraction < or =30% who required hospitalization for heart failure, we examined the association between outpatient dose of diuretic agents and all-cause mortality. In comparison to patients who were not on treatment with diuretics prior to hospitalization, patients being treated with 'low' doses of diuretics (<80 mg/day of furosemide) and those being treated with 'high' doses of diuretics (> or =80 mg/day of furosemide) were more likely to die during follow-up after adjustment for other clinical parameters (adjusted relative risks, RR, 3.1 and 4.6).

Does left ventricular shape influence clinical outcome in heart failure?

BACKGROUND: Left ventricular (LV) shape tends to become spherical in patients with dilated cardiomyopathy of diverse etiology. Clinical and echocardiographic factors which affect the degree of LV spherical distortion and the impact of altered LV shape on prognosis have not been studied adequately. HYPOTHESIS: This study was undertaken to investigate the prognostic implications of altered LV shape on clinical outcome in dilated cardiomyopathy. METHODS: In 112 patients with depressed LV ejection fraction (19 +/- 9%) and symptomatic heart failure, and in 10 age- and gender-matched normal controls, we performed 2-dimensional echocardiography to assess LV shape using the eccentricity index. Eccentricity index was defined as the ratio of the LV long axis to the LV transverse diameter, measured at end systole and end diastole in the apical four-chamber view. We sought univariate and multivariate clinical and echocardiographic correlates of LV shape. Further, we sought correlations between eccentricity index and clinical outcomes (death and composite outcome of death or emergent heart transplant). RESULTS: Compared with controls, patients with cardiomyopathy had significantly lower systolic (2.04 vs. 1.56; p = 0.001) and diastolic (1.75 vs. 1.53; p = 0.003) eccentricity index, implying a more spherical LV shape. Of all clinical and echocardiographic variables tested, mitral regurgitation, right ventricular dysfunction, and increased LV mass were independently associated with spherical LV shape. At a follow-up period of 17 +/- 12 months, no correlation was found between eccentricity index and the occurrence of death or the combined endpoint of death or emergent heart transplant, in univariate or multivariate analysis. CONCLUSIONS: In patients with dilated cardiomyopathy, the degree of spherical distortion of the LV does not correlate with prognosis.

The independent effects of left ventricular ejection fraction on short-term outcomes and resource utilization following hospitalization for heart failure.

BACKGROUND: While depressed left ventricular ejection fraction is clearly associated with poor long-term outcome in heart failure (HF), the effect of ejection fraction on short-term outcomes and resource utilization following hospitalization for HF remains unclear. HYPOTHESIS: We evaluated the independent effect of depressed ejection fraction (< or = 40%) on short-term outcomes and resource utilization following hospitalization for HF. METHODS: The study population included 443 consecutive patients hospitalized for DRG 127 (HF and shock) with known ejection fraction. For each patient, we assessed the hospitalization cost (1995 US$), length of stay, in-hospital mortality, 30-day mortality, and 30-day readmission rates. RESULTS: Despite similar disease severity at admission, patients with ejection fraction < or = 40% (Group 1) had longer length of stay (4.0 vs. 3.7 days; p = 0.03), a tendency toward higher hospitalization cost ($3,054 vs. $2,770; p = 0.08), more readmissions for any cause (0.4 vs. 0.3; p = 0.05) and for HF (0.2 vs. 0.1; p = 0.01), but similar in-hospital (2.5 vs. 2.6%) and 30-day mortality (4.0 vs. 4.6%) compared with patients with ejection fraction > 40% (Group 2). In multivariate analyses, Group 1 patients were more likely to have higher than median hospitalization cost [odds ratio (OR) = 1.98; 95% confidence intervals (CI) = 1.02-3.91] and longer than median hospital stay (OR = 1.68; CI = 1.08-3.91); they were also more likely to be readmitted for any cause (OR = 2.07; CI = 1.15-3.78) or for HF (OR = 5.71; CI = 1.64-21.94), and they tended to have a higher 30-day incidence of death or readmission (OR = 1.65; CI = 0.96-2.84). CONCLUSIONS: Depressed left ventricular ejection fraction is associated with higher resource utilization and readmission rates following hospitalization for HF. Greater focus on patients with depressed ejection fraction may increase cost savings from HF disease management programs.