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George Kallos, Marina Astitha, Petros Katsafados, and Chris Spyrou

of air pollutants released from Europe toward the eastern Mediterranean and North Africa ( Katsoulis and Whelpdale 1990 ; Luria et al. 1996 ; Kallos et al. 1997 , 1998a , b ; Millán et al. 1997 , 2005 ; Peleg et al. 1997 ; Gangoiti et al. 2001 ). Recent studies focus on the importance of long-range transport patterns of particulate matter (PM) of anthropogenic and natural origin as shown by Prospero et al. (2001) , Uno et al. (2001) , Rodriguez et al. (2001) , Bardouki et al. (2003

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Golam Sarwar and Prakash V. Bhave

1. Introduction Tropospheric ozone (O 3 ) is produced by complex reactions involving volatile organic compounds (VOC), nitrogen oxides (NO x ), and atmospheric oxidants in the presence of sunlight. Historically, chlorine emissions have not been included in photochemical models for air quality and, thus, the effects of such emissions on O 3 have been neglected. The effect of chlorine chemistry on O 3 has been studied as early as 1985 ( Hov 1985 ). The author used a photochemical model that

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M. Talat Odman, Yongtao Hu, Alper Unal, Armistead G. Russell, and James W. Boylan

height of approximately 14 km. The lowest four layers were 36 m thick. Earlier evaluations of the effects of the number of layers and layer thicknesses showed that this setup is adequate for modeling surface layer concentrations and deposition fluxes even during stable nighttime conditions ( Morris et al. 2004 ). Anthropogenic emissions were considered in ground-level and elevated source categories. Ground-level sources include on-road and nonroad mobile sources, area sources, and area fires

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Armin Aulinger, Volker Matthias, and Markus Quante

1. Introduction Polycyclic organic hydrocarbons (PAHs) belong to the so-called persistent organic pollutants (POPs), a group of substances with known adverse effects on ecosystems and human health. Single ones or mixtures of these compounds can, for example, cause cancer or impair reproduction ( Mumatz and George 1995 ). The concentrations of PAHs in the environment are relatively low, but they gain their extraordinary ecotoxicity from their persistency in various environmental compartments

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Edith Gégo, P. Steven Porter, Alice Gilliland, and S. Trivikrama Rao

anthropogenic emissions would affect the intraday and diurnal variations of ozone, pointing to a high degree of local control. More important to us, they showed that reducing emissions from large elevated point sources has a limited effect on short-term time scales but has substantial effects at longer time scales (synoptic and longer), pointing to a regional control of ozone variations (i.e., pollution transport–based control). Following the results of Hogrefe et al. (2000) , we calculated the standard

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Ho-Chun Huang, Xin-Zhong Liang, Kenneth E. Kunkel, Michael Caughey, and Allen Williams

1. Introduction Human activities have led to several important air quality issues, such as elevated tropospheric ozone (O 3 ), particulate matter, and visibility problems, which affect human health and the natural environment. Anthropogenic increases in atmospheric concentrations of greenhouse gases also are increasing concerns about future climate change ( Houghton et al. 2001 ). Global warming could have detrimental effects on future air quality, such as increased frequency of harmful

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