Airborne particulates, accumulation

To find answers to these crucial questions and to establish if the occurrence of psychotropic substances in the atmospheric aerosols is just a curiosity or rather a potential problem for the community, a series of investigations have been carried out both in the laboratory and in the field. Dedicated procedures have been optimised, for instance, for cocaine and cannabinoids (see sections below), and the chemical stability of cocaine in airborne particulates and its partition between gas and aerosol phases were estimated, as well as its accumulation in fine rather than coarse particles. Furthermore, cocaine and cannabinoids concentrations have been measured in several cities over the world through field studies. After the first detection of cocaine in ambient air by Hannigan et al. [1] in Los Angeles, measurements were performed more extensively in Italy (for instance over 10 consecutive months in downtown Rome, or in 38 Italian localities) and Spain... 

The objective of this paper aims to present recent studies on the ecological and human health impacts resulting from the deposition of coal fly-ash particulates from emissions due to fossil fuel combustion within the Pechora Basin. Problems exist when monitoring airborne particulate deposition around urban centers, as air and precipitation chemistries show high temporal and spatial variation (e.g. Reimann et al. 1999). Elemental concentrations are usually low and sample contamination is a significant problem. Approaches include the analysis of ecological materials that accumulate contaminants (e.g. snow, soils and lichens) which become modified by exposure to pollution from airborne particulate deposition. 

As informed Dr. A.I. Korableva from Institute for Environmental Management and Ecology under the National Academy of Sciences of Ukraine in the report "Environmental impact of automobile transport by example of Dnepropetrovsk", Dnepropetrovsk with its annual discharge of air pollutants of 177,000 t (as of 1996) is among the worst affected cities in Ukraine. In these, the automobile transport was found to be responsible for at least 30 % of the total emissions which are 15 times the maximum permissible level. Aside from the dust, chemical, photochemical and noise pollution, there is the aspect of street washout of automobile-related pollutants into the River Dnieper. The measured annual receipts of lead, particulates and petroleum derivatives via rainwater and thaw water to the river are 0.45, 80,000+ and 1.8+ t respectively. The actual levels of petroleum derivatives in storm water sometimes were 206 times the maximum permissible concentration (MPC) for the fishery basins. At 34 km downstream from the city, the estimated levels of petroleum derivatives and particulates are 61 and 10.8 times the respective MPCs. The airborne lead is mainly accumulated in the soil of housing areas. 

Most of the studies on size-resolved aerosol mass concentrations in areas with different levels of pollution show that particulate matter typically exhibit a bimodal distribution, with most of their mass being found in the submicron size range (dae < 1pm) and an additional minor mode in the coarse fraction (1 < dae < 10 pm) (Maenhaut et al., 2002 Smolfk et al., 2003 Wang et al., 2003 Gajananda et al., 2005 Samara and Voutsa, 2005). However, with instrumentation allowing more precise measurements, the aerosol mass size distribution was found to be multimodal with the preponderance of a fine mode (dae < 0.2 pm) and an accumulation mode (dae 0.5pm), with a minor coarse mode at d 3-4pm (Raes et al., 2000 Pillai and Moorthy, 2001 Berner et al., 2004). Traditionally, atmospheric researchers classify airborne particles into three size classes coarse (2.5 < c/ ie < 10pm), fine... 

A significant health concern with particles, especially those from combustion sources, is their ability to carry toxic metals. Of these, lead is of the greatest concern because it usually comes closest to being at a toxic level. Problems with particulate lead in the atmosphere have been greatly reduced by the elimination of tetraethyl lead as a gasoline additive, an application that used to spew tons of lead into the atmosphere every day. Another heavy metal that causes considerable concern is mercury, which can enter the atmosphere bound to particles or as vapor-phase atomic mercury. Airborne mercury from coal combustion can become a serious water pollution problem, leading to unhealthy accumulations of this toxic element in some fish. Other metals that can cause health problems in particulate matter are beryllium, cadmium, chromium, vanadium, nickel, and arsenic (a metalloid). 

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