Soil and sediment samples from James Ross Island were analyzed for their PCB, OCP and PAH contents. Soil concentrations ranged between 0.51 and 1.82 ng g-1 for seven indicator PCB congeners, between 0.49 and 1.34 ng g-1 for HCH congeners, between 0.51 and 3.68 ng g-1 for the sum of p,p'-DDT, DDE, and DDD, and between 34.9 and 171 ng g-1 for the sum of 16 EPA PAHs. Sediment levels from 0.32 to 0.83 ng g-1 were found for PCBs, from 0.14 to 0.76 ng g-1 for HCHs, from 0.19 to 1.15 ng g-1 for DDTs, and from 1.4 to 205 ng g-1 for PAHs. A prevalence of low-mass PAHs, less chlorinated PCBs, and more volatile chemicals indicates that the long-range atmospheric transport from populated areas of Africa, South America, and Australia is the most probable contamination source for the solid matrices in James Ross Island. A survey of soil, sediment and air contamination in James Ross Island, Antarctica serves as a baseline study for evaluation of an anthropogenic impact of the new research facility.

Particulate matter measurements (PM₁₀, PM₂.₅) using a beta radiation attenuation monitor were performed at the Akrotiri research station (May 2003-March 2006) on the island of Crete (Greece). The mean PM₁₀ concentration during the measuring period (05/02/03-03/09/04) was equal to 35.0 ± 17.7 μg/m³ whereas the mean PM₂.₅ concentration (03/10/04-04/02/06) was equal to 25.4 ± 16.5 μg/m³. The aerosol concentration at the Akrotiri station shows a large variability during the year. Mean concentrations of particulate matter undergo a seasonal change characterised by higher concentrations during summer [PM₁₀, 38.7 ± 10.8 μg/m³ (2003); PM₂.₅, 27.9 ± 8.7 μg/m³ (2004) and 27.8 ± 9.7 μg/m³ (2005)] and lower concentrations during winter [PM₁₀, 28.7 ± 22.5 μg/m³ (2003/2004); PM₂.₅, 21.0 ± 13.0 μg/m³ (2004/2005) and 21.4 ± 21.9 μg/m³ (2005/2006)]. Comparative measurements of the PM₁₀ concentration between the beta radiation attenuation monitor, a standardized low volume gravimetric reference sampler and a low volume sequential particulate sampler showed that PM₁₀ concentrations measured by the beta radiation attenuation monitor were higher than values given by the gravimetric samplers (mean ratio 1.17 ± 0.11 and 1.21 ± 0.08, respectively). Statistical and back trajectory analysis showed that elevated PM concentrations (PM₁₀, 93.8 ± 49.1 μg/m³; PM₂.₅: 102.9 ± 59.9 μg/m³) are associated to desert dust events. In addition regional transport contributes significantly to the aerosol concentration levels whereas low aerosol concentrations were observed during storm episodes.

The aim of the present work is to characterize the local atmospheric emissions levels and compare them to the component derived from global pollution in a remote site at South Hemisphere (Admiralty Bay located at King George Island in Antarctic Peninsula). Airborne particles, snow and soil/sediments samples were analyzed. Local-produced atmospheric aerosol dispersion was estimated for metals originated by fossil fuel burning from the permanent scientific stations using a simplified Gaussian model. Validation of atmospheric dispersion was established by in situ measurements. Soluble and insoluble particles deposited in freshly snow and airborne particles were analyzed by PIXE (Particle Induced X-Ray Emission) for the determination of the elemental mass concentration and to obtain the Mass Median Aerodynamic Diameter (MMAD). The results showed significant correlation between the concentration of atmospheric aerosol and the freshly deposited particles in the snow, and permitted an estimate of the atmospheric snow deposition factor for K, Cu, Zn, Fe, Pb, and Ti. Results of long-term aerosol data compilation suggest that besides the local aerosol sources, the continental atmospheric transport of airborne particles is not significantly affected by the airborne particles produced by local human impacts at King George Island.

Sensitivities of the forecast to changes in the initial state are evaluated for an Asian dust event, which affected the Korean Peninsula on 7 to 9 April 2006, to understand the impact of initial condition uncertainties on the forecast and thence to suggest the sensitive regions for adaptive observations of the Asian dust. To assess the forecast sensitivities, adjoint-based sensitivities were used. Sensitive regions are located over the northwestern part of Mongolia at the initial time, then propagate to Inner Mongolia and Manchuria. Close to the verification time, sensitive regions as determined by adjoint-based forecast sensitivities coincide with the passage of the Asian dust. Forecast error for the atmospheric circulation during the dust event is reduced 57.4% by extracting properly weighted adjoint-based forecast sensitivity perturbations from the initial state, and the correction occurs primarily in the upper troposphere where the forecast error is the largest. The improvement in the overall forecast implies that adjoint-based forecast sensitivities would be beneficial in determining the observational sites and in improving the forecast of Asian dust events. An additional experiment with another Asian dust event confirms the validity of adjoint-based forecast sensitivities to Asian dust events.

The major objective of this paper is to provide insights to sources and sinks of nitrous acid in urban areas, and their seasonal dependency on meteorology, photochemistry and long range transport. With this aim, nitrous acid (HONO) mixing ratios and other compounds were measured in Ashdod (south of Tel Aviv, Israel), a typical Mediterranean urban area. Statistical data analysis revealed the expected correlation between HONO and nitrogen oxides during the autumn campaign when HONO sources appeared to be traffic-, harbor-, and industry-related. Conversely, during summer HONO and NO₂ were no longer correlated: NO₂ at nighttime was probably deposited onto surfaces, soil and plants, whereas HONO at daytime was likely destroyed photolytically contributing to the OH concentration. Photolysis was expected to be the dominant HONO sink at daytime, especially during the summer period. Using modeled photolytical HONO lifetimes we estimate the magnitude of heterogeneous and/or organic electron transfer source reactions of HONO as 6-8 ppbv/h.

A 12 months study on urban atmospheric concentrations of polycyclic aromatic hydrocarbons (PAH) contained in the particulate matter with an aerodynamic diameter less than or equal to 10 microns (PM10) was carried out in Zaragoza (Spain) from July 12th, 2001 to July 26th, 2002 by using a high-volume air sampler able to collect the PAH supported on a Teflon-coated fibre glass filter. Samples were analysed by using Gas Chromatography Mass Spectrometry (GC-MS/MS). PAH of high molecular weight, indeno[1,2,3-cd]pyrene (IcdP), benzo[g,h,i]perylene (BghiP) and coronene (Co) were the most abundant compounds. The concentrations of benz[a]pyrene equivalent carcinogenic power (BaP-eq) showed a mean value of 0.7 ng/m³ with 22.5% of the samples exceeding the 1.0 ng/m³ guide value established by the European Directive. These episodes were mainly produced during cold season. Regarding meteorological variables, a positive effect of the prevalent wind “cierzo” (NW direction) over the Zaragoza city was confirmed from the environmental point of view. The NE, E and S directions, corresponding to highway and industrial areas were the directions showing the high PAH atmospheric concentrations. Despite the proximity of a high-level traffic highway, stationary sources related to industry were the dominant source of PAH in the sampled area. Vehicular emissions and natural gas home heating also contributed to PAH concentrations. The predominance of local pollution sources versus long-range transport on PAH concentrations was shown. However, the contribution of long-range transport of anthropogenic origin from other European areas was reflected for specific dates on PAH concentrations and PM10 levels.

Nitrated Polycyclic Aromatic Hydrocarbons (NPAH) were determined in the suspended particulates collected in São Paulo (Brazil) and three other cities lying in the São Paulo State, (namely, Araraquara, Piracicaba and Paulínia), during August 2002 and July 2003. São Paulo samples represented a big difference between two groups of days, one of which characterized by heavy injection of pollutants released by industrial and agricultural activities. Most NPAH congeners identified in the atmosphere were among those usually associated to diesel exhaust, with the three important exceptions of 2-nitrofluoranthene, 2- and 4-nitropyrene. Daytime reactions seemed to promote decomposition of primary fluoranthene and pyrene. Trends of NPAH at all sites seemed to be associated to regional transport of polluted air through air masses passing over sugar cane plantations of São Paulo State.