Health Risk Assessment for Residents and Workers Based on Toxic and Carcinogenic Element Content from PM2.5 in Belgrade Suburban Area

Particulate matter of diametar 1) and carcinogenic (R≥1×10-5) risks for the residents from this area. The residents spent the most of their time in this ambient and they are most at the risk caused by the measured PM2.5 pollution (HImedian: 2.28; Rmedian: 1.25 × 10-4). Observing the scenarios for workers, the risk mostly depends on the time that workers spent outside during working hours. Similar non-carcinogenic risks were observed for outdoor, indoor and composite workers, slightly higher risk was observed for construction workers, while the lowest risk was obtained for an excavation worker who is less exposed to the PM2.5 atmospheric deposition than soil dust resuspension. The same was observed for the carcinogenic risk, while the similar risks were observed for all workers. Only for an excavation worker, the carcinogenic risk was significantly lower than for other workers. The most significant contributor to the non-carcinogenic risk in all scenarios was the concentration of Mn, and then the concentration of Be, while the most significant contributor to the carcinogenic risk was Cr6+. Observing the risks among the investigated period the highest non-carcinogenic and carcinogenic risks were observed in April and October based on the toxic and carcinogenic elements in PM2.5. In these months beside the influence of the industrial activities, dust episodes or activity of heating sorces possibly caused the increase of the toxic and carcinogenic elements in PM2.5

Aerosol properties computed from aircraft-based observations during the ACE- Asia campaign

For a vertical profile with three distinct layers (marine boundary, pollution and dust), observed during the ACE-Asia campaign, we carried out a comparison between the modeled lidar ratio vertical profile and that obtained from collocated airborne NASA AATS-14 sunphotometer and shipborne Micro-Pulse Lidar (MPL) measurements. Vertically resolved lidar ratio was calculated from two size distribution vertical profiles - one obtained by inversion of sunphotometer-derived extinction spectra, and one measured in-situ - combined with the same refractive index model based on aerosol chemical composition. The aerosol model implies single scattering albedos of 0.78 - 0.81 and 0.93 - 0.96 at 0.523 microns (the wavelength of the lidar measurements), in the pollution and dust layers, respectively. The lidar ratios calculated from the two size distribution profiles have close values in the dust layer; they are however, significantly lower than the lidar ratios derived from combined lidar and sunphotometer measurements, most probably due to the use of a simple nonspherical model with a single particle shape in our calculations. In the pollution layer, the two size distribution profiles yield generally different lidar ratios. The retrieved size distributions yield a lidar ratio which is in better agreement with that derived from lidar/sunphotometer measurements in this layer, with still large differences at certain altitudes (the largest relative difference was 46%). We explain these differences by non-uniqueness of the result of the size distribution retrieval and lack of information on vertical variability of particle refractive index. Radiative transfer calculations for this profile showed significant atmospheric radiative forcing, which occurred mainly in the pollution layer. We demonstrate that if the extinction profile is known then information on the vertical structure of absorption and asymmetry parameter is not significant for estimating forcing at TOA and the surface, while it is of importance for estimating vertical profiles of radiative forcing and heating rates

On interactions between (1) Ceres and (2) Pallas

Mutual perturbing effects between (1) Ceres and (2) Pallas are presented by using differences in their right ascensions and declinations. These differences are obtained as the result of two integrations-with and without the mass of the perturbing body. For each body are performed two backward and two forward integrations and obtained results are analyzed

Motion of the asteroid (13206) 1997GC22 and the mass of (16) Psyche

From the perturbing effects of the asteroid (16) Psyche on the motion of the asteroid (13206) 1997GC22 the mass of (16) Psyche is determined. A close approach between these two asteroids at $0.00376\, {\rm AU}$, and at a relative velocity of $0.74 \, {\rm km\, s^{-1}}$, occured in July 1974. The value of $(3.38\pm 0.28)\, 10^{-11}~{M_{\odot}}$ has been found for the mass of (16) Psyche, which yields a density of $(6.98\pm0.58)\,{\rm g\,cm^{-3}}$. These values are very different from those obtained by other authors, but the mass is much closer to the value based on the IRAS estimation of (16) Psyche diameter and its M-type taxonomical classification

Aerosol Properties Computed from Aircraft-Based Observations during the ACE-Asia Campaign: 1. Aerosol Size Distributions Retrieved from Optical Thickness Measurements

In this article, aerosol size distributions retrieved from aerosol layer optical thickness spectra, derived from the 14-channel NASA Ames Airborne Tracking Sunphotometer (AATS-14) measurements during the ACE-Asia campaign, are presented. Focusing on distinct aerosol layers (with different particle characteristics) observed in four vertical profiles, we compare the results of two different retrieval methods: constrained linear inversion and a nonlinear least squares method. While the former does not use any assumption about the analytical form of the size distribution, the latter was used to retrieve parameters of a bimodal lognormal size distribution. Furthermore, comparison of the retrieved size distributions with those measured in-situ, aboard the same aircraft on which the sunphotometer was flown, was carried out. Results of the two retrieval methods showed good agreement in the radius ranges from ~0.1 μm to ~1.2–2.0 μm, close to the range of retrievable size distributions from the AATS-14 measurements. In this radius interval, shapes of retrieved and measured size distributions were similar, in accord with close wavelength dependencies of the corresponding optical thicknesses. Additionally, the effect of a size-resolved refractive index on the retrieved size spectra was investigated in selected cases. Retrieval using a constant refractive index pertaining to particle sizes within the range of retrievable size distributions resulted in a size distribution very close to the one retrieved using a size-resolved refractive index

Air quality in urban parking garages (PM10, major and trace elements, PAHs): Instrumental measurements vs. active moss biomonitoring

This study was performed in four parking garages in downtown of Belgrade with the aim to provide multi-pollutant assessment. Concentrations of 16 US EPA priority PAHs and Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr and Zn were determined in PM10 samples. The carcinogenic health risk of employees' occupational exposure to heavy metals (Cd, Cr, Ni and Pb) and PAHs (B[a]A, Cry, B[b]F, B[k]F, B[a]P and DB[ah]A) was estimated. A possibility of using Sphagnum girgensohnii moss bags for monitoring of trace element air pollution in semi-enclosed spaces was evaluated as well. The results showed that concentrations of PM10, Cd, Ni and B[a]P exceeded the EU Directive target values. Concentration of Zn, Ba and Cu were two orders of magnitude higher than those measured at different urban sites in European cities. Cumulative cancer risk obtained for heavy metals and PAHs was 4.51 x 10(-5) and 3.75 x 10(-5) in M and PP, respectively; upper limit of the acceptable US EPA range is 10(-4). In the moss, higher post-exposure than pre-exposure (background) element concentrations was observed. In comparison with instrumental monitoring data, similar order of abundances of the most elements in PM10 and moss samples was found. However, using of the S. girgensohnii moss bag technique in indoor environments needs further justification. (C) 2013 Elsevier Ltd. All rights reserved

Aerosol Properties Computed from Aircraft-Based Observations During the ACE-Asia Campaign: 2. A Case Study of Lidar Ratio Closure

For a vertical profile with three distinct layers (marine boundary, pollution, and dust layers), observed during the ACE-Asia campaign, we carried out a comparison between the modeled lidar ratio vertical profile and that obtained from co-located airborne NASA AATS-14 sunphotometer and shipborne Micro-Pulse Lidar (MPL) measurements. The vertically resolved lidar ratio was calculated from two size distribution vertical profiles—one obtained by inversion of sunphotometer-derived extinction spectra, and one measured in-situ—combined with the same refractive index model based on aerosol chemical composition. The aerosol model implies single scattering albedos of 0.78–0.81 and 0.93–0.96 at 0.523 μm (the wavelength of the lidar measurements), in the pollution and dust layers, respectively. The lidar ratios calculated from the two size distribution profiles agree closely in the dust layer; they are however, significantly lower than the lidar ratios derived from combined lidar and sunphotometer measurements. Uncertainties in aerosol size distributions and refractive index only partly explain these differences, suggesting that particle nonsphericity in this layer is an additional explanation. In the pollution layer, the two size distribution profiles yield lidar ratios that agree within the estimated uncertainties. The retrieved size distributions result in a lidar ratio which is in closer agreement with that derived from lidar/sunphotometer measurements in this layer, with still large differences at certain altitudes (the largest relative difference was 46%).We explain these differences by non-uniqueness of the result of the size distribution retrieval, by a lack of information on the mixing state of particles, and the vertical variability of the particle refractive index