1. Determining the Aethalometer multiple scattering enhancement factor C from the filter loading parameterLuca Ferrero, Niccolò Losi, Martin Rigler, Asta Gregorič, C. Colombi, L. D'Angelo, E. Cuccia, A. M. Cefalì, I. Gini, A. Doldi, 2024, original scientific article Abstract: Light-absorbing aerosols heat the atmosphere; an accurate quantification of their absorption coefficient is mandatory. However, standard reference instruments (CAPS, MAAP, PAX, PTAAM) are not always available at each measuring site around the world.
By integrating all previous published studies concerning the Aethalometers, the AE33 filter loading parameter, provided by the dual-spot algorithm, were used to determine the multiple scattering enhancement factor from the Aethalometer itself (hereinafter CAE) on an yearly and a monthly basis. The method was developed in Milan, where Aethalometer measurements were compared with MAAP data; the comparison showed a good agreement in terms of equivalent black carbon (R2 = 0.93; slope = 1.02 and a negligible intercept = 0.12 μg m−3) leading to a yearly experimental multiple scattering enhancement factor of 2.51 ± 0.04 (hereinafter CMAAP). On a yearly time base the CAE values obtained using the new approach was 2.52 ± 0.01, corresponding to the experimental one (CMAAP). Considering the seasonal behavior, higher experimental CMAAP and computed CAE values were found in summer (2.83 ± 0.12) whereas, the lower ones in winter/early-spring (2.37 ± 0.03), in agreement with the single scattering albedo behavior in the Po Valley.
Overall, the agreement between the experimental CMAAP and CAE showed a root mean squared error (RMSE) of just 0.038 on the CMAAP prediction, characterized by a slope close to 1 (1.001 ± 0.178), a negligible intercept (−0.002 ± 0.455) and a high degree of correlation (R2 = 0.955). From an environmental point of view, the application of a dynamic (space/time) determination of CAE increases the accuracy of the aerosol heating rate (compared to applying a fixed C value) up to 16 % solely in Milan, and to 114 % when applied in the Arctic at 80°N.
Keywords: aethalometer, C factor, loading parameter, MAAP, heating rate
Published in RUNG: 02.02.2024; Views: 460; Downloads: 4
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4. Carcinogenic organic content of particulate matter at urban locations with different pollution sourcesGordana Pehnec, Ivana Jakovljević, Ranka Godec, Zdravka Sever Štrukil, Sabina Žero, Jasna Huremović, Katja Džepina, 2020, original scientific article Abstract: Polycyclic aromatic hydrocarbons (PAHs) are compounds known for their adverse effects on human health. Many of them are proven carcinogens, especially those with 5 and 6 aromatic rings, which under normal tropospheric conditions are found in the particle-phase. Benzo(a)pyrene (BaP) is often measured as their general representative. Sarajevo, the capital of Bosnia and Herzegovina, is among the European cities with the poorest air quality. However, in Sarajevo PAHs are neither routinely measured within the air quality monitoring network nor have been a subject of extended, continuous field studies during the most polluted cold periods of the year. The capital of Croatia, Zagreb, is located approximately 300 km air distance north-west from Sarajevo.
PAH mass concentrations in Zagreb have been measured continuously since 1994 within air quality monitoring networks. During winter 2017/2018, the SAFICA project (Sarajevo Canton Winter Field Campaign 2018) was carried out in order to characterize the chemical composition of organic and inorganic aerosol in the Sarajevo Canton. This paper presents the results of PAH measurements in the cities of Sarajevo and Zagreb at one urban
location per city. Daily (24 h), continuous samples of PM10 (particulate matter with aerodynamic diameters
≤10 μm) were collected during heating season, from December 27, 2017 to February 27, 2018. Mass concentrations of eleven particle-phase PAHs in Sarajevo and Zagreb from filter samples collected during the same period were compared. The average BaP ambient mass concentrations in Sarajevo and Zagreb were 6.93 ng m−3 and 3.11 ng m−3, respectively. The contribution of BaP to the total PAH mass concentration was similar at both locations (11%). However, much higher contributions of particle-phase fluoranthene and pyrene were found in Sarajevo. Contributions of individual PAH, diagnostic ratios and factor analysis indicate that combustion of gasoline and diesel from vehicle traffic are a potential source of PAHs at both locations, as well as combustion of other liquid fossil fuels (petroleum and fuel oil). Wood burning was occasionally indicated as a PAH emission source in
Zagreb, while in Sarajevo the contribution of PAHs from wood and coal combustion was more evident. Calculated value for total carcinogenic potency (TCP) of PAHs, which was estimated using toxic equivalence factors from the literature, in PM10 samples collected in Sarajevo was more than twice higher than in Zagreb (10.6 ng m−3 and 4.7 ng m−3, respectively). BaP had the highest contribution to the TCP at both locations (69 and 67%).
Keywords: carcinogenic potency, diagnostic ratio, factor analysis, PM10, polycyclic aromatic hydrocarbons
Published in RUNG: 09.04.2021; Views: 2173; Downloads: 0
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6. Methyl halide emission estimates from domestic biomass burning in AfricaM Iqbal Mead, M Anwar H Khan, Iain R. White, Graham Nicless, Dudley E Shallcross, 2008, original scientific article Abstract: Inventories of methyl halide emissions from domestic burning of biomass in Africa, from 1950 to the present day and projected to 2030, have been constructed. By combining emission factors from Andreae and Merlet [2001. Emission of trace gases and aerosols from biomass burning. Global Biogeochemical Cycles 15, 955-966], the biomass burning estimates from Yevich and Logan [2003. An assessment of biofuel use and burning of agricultural waste in the developing world. Global Biogeochemical Cycles 17(4), 1095, doi:10.1029/2002GB001952] and the population data from the UN population division, the emission of methyl halides from domestic biomass usage in Africa has been estimated. Data from this study suggest that methyl halide emissions from domestic biomass burning have increased by a factor of 4-5 from 1950 to 2005 and based on the expected population growth could double over the next 25 years. This estimated change has a non-negligible impact on the atmospheric budgets of methyl halides.
Keywords: Africa, Biofuel, Domestic biomass burning, Emission factor, Methyl halide
Published in RUNG: 17.07.2019; Views: 3240; Downloads: 0
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8. ASSESSMENT OF EFFECTIVE DOSES BASED ON VARIOUS RADON MEASURING TECHNIQUESNataša Smrekar, 2016, master's thesis Abstract: In my master's thesis, I have focused on radon gas in 43 buildings used for different purposes (23 schools, 3 kindergartens, 16 offices and a residential house) in which preliminary measurements had shown higher concentrations of radon gas. I carried out measurements of radon and short-lived radon products whilst simultaneously employing different measurement techniques. In all 43 buildings, I measured the instantaneous concentration of radon by using scintillation cells; in 18 buildings, I additionally measured the average concentration of radon by using solid state nuclear track detectors and in 10 buildings, I measured concentration retrospectively with solid state nuclear track detectors. In four selected buildings (a school, a kindergarten, an office and a residential house), I carried out the measurements by using all of the available equipment. I monitored the daily fluctuations of concentration of radon and short-lived radon products by using continuous monitors in 14 buildings. This is how I obtained the factor of radioactive equilibrium between radon and its short-lived products. Based on the results obtained, I calculated the effective doses. As the basis for calculating the doses, I used the instantaneous and average concentrations of radon and the equilibrium factor taken from literature (0.40) or own measurements. I compared the doses and critically evaluated them.
In contrast to the previous research, I researched radon exclusively in areas with increased risk for radon. I studied the influence of the working regime on the concentration of radon in different working environments (i.e. a school, a kindergarten and an office).
Keywords: Radon, short-lived radon products, measurement technique, scintillation cell, solid-state nuclear track detector, retrospective detector, equilibrium factor, effective dose, comparison.
Published in RUNG: 28.09.2016; Views: 6265; Downloads: 283
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9. Diagnostic and prognostic markers in canine inflammatory and neoplastic head and neck conditions : dissertationAna Rejec, 2015, doctoral dissertation Abstract: Several different types of conditions with inflammatory and neoplastic background affect the anatomical localities of the head and neck in a dog. It is a well-recognized fact that these conditions affect the quality of life, as they are associated with various degree of regional dysfunction, have systemic effects and can be direct or indirect cause of death. Unfortunately, many dogs with both inflammatory and neoplastic head and neck conditions are presented at an advanced stage of the disease which can have significant impact on treatment strategies. The identification of biomarkers is advisable to enhance effective staging, grading and prognostication, which will in turn more accurately direct recommendations for therapy.
These biomarkers can theoretically help to distinguish between inflammatory and neoplastic conditions, justify the management of patients more accurately and potentially predict the prognosis and the survival of patients.
It was our interest to investigate the diagnostic and prognostic value of complete blood count parameters and indices in dogs with head and neck conditions of inflammatory and neoplastic origin, regulatory T cells in dogs with periodontal disease, immunohistochemical (Ki-67 and VEGFR-2) and histopathological biomarkers in dogs with inflammatory and neoplastic head and neck conditions and to evaluate the effectiveness of an accelerated radiotherapy protocol for the treatment of advanced canine HNSCC.
We have proved that the parameters investigated might serve as important supportive diagnostic and/or prognostic biomarkers which might help to improve the treatment strategies of both inflammatory and neoplastic head and neck conditions in dogs and that the accelerated chemoradiotherapy protocol represents an effective alternative treatment option for dogs with advanced HNSCC.
Keywords: biomarkers, dogs, periodontal disease, regulatory T cells, head and neck tumours, complete blood count, radiotherapy, vascular endothelial growth factor receptor 2
Published in RUNG: 26.11.2015; Views: 6010; Downloads: 121
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