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Anthropogenic Change Regime of Tropospheric Ozone in the Mediterranean and Global Environment

Ozturk F, Keles M and Evrendilek F^*

Department of Environmental Engineering, Abant Izzet Baysal University, 14280 Bolu, Turkey

*Corresponding Author:

Evrendilek F
Abant Izzet Baysal University, Faculty of Engineering and Architecture
Department of Environmental Engineering
Golkoy Campus, 14280 Bolu, Turkey
Tel: +90374 254 2665
Fax: +90374 253 4558
E-mail: fevrendilek@ibu.edu.tr

Received date: July 31, 2015; Accepted date: August 01, 2015; Published date: August 03, 2015

Citation: Ozturk F, Keles M, Evrendilek F (2015) Anthropogenic Change Regime of Tropospheric Ozone in the Mediterranean and Global Environment. J Ecosys Ecograph 5: e122. doi:10.4172/2157-7625.1000e122

Copyright: © 2015 Ozturk F, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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Editorial

Tropospheric ozone (O₃) is one of the atmospheric pollutants and a key oxidant in photochemical smog, and formation of groundlevel O₃ is a photochemically driven process in which nitrogen oxides (NOx), carbon monoxide (CO), and volatile organic compounds (VOCs) react in the atmosphere in the presence of solar radiation [1]. Ozone precursors are mainly released from motor vehicles, industrial activities, and power generation facilities, while vegetative emissions, wildfires, and lightning are considered to be the natural sources of O₃ precursor gases. Surface deposition and reaction with the hydrogen peroxy radical in the troposphere are the two main sinks for groundlevel O₃ [2]. Since the formation of O₃ is stimulated with the increased air temperature, O₃ concentrations show a peak once the solar radiation peaks. Daily and diurnal O₃ variations for a cool temperate location (Bolu, Turkey) were depicted in Figure 1. A daytime peak (~35 ppbv) was observed in the early afternoon between 12:00 and 15:00. Similar patterns have been observed for ground-level O₃ in related literature [3]. Since the 1950s, a significant number of studies in related literature have focused on the adverse impacts of ground-level O₃ on human health [4], crops [5], forests [6], and materials [7]. O₃ is the third most significant greenhouse gas (GHG) in terms of radiative forcing [8]. Therefore, such international organizations as the World Health Organization (WHO), the United States Environmental Protection Agency (USEPA), and the European Union (EU) have set guidelines for O₃. The daily maximum eight-hour mean O₃ threshold limit is 100 μg m-3 by WHO [9] and 0.075 ppm by the USEPA for National Ambient Air Quality Standards [10]. The maximum daily eight-hour mean (120 μg m-3) should not be exceeded for more than 25 days per year so as to be averaged over three consecutive years according to the EU regulations with Directive/2008/50/EC.

The Mediterranean basin is characterized by a strong photochemical activity and adversely affected by the emissions from different regions with a variety of chemical composition and is especially susceptible to air pollution because of the cloud-free atmosphere and elevated solar radiation intensity [11]. According to the IPCC [8], the climate change will be more pronounced in the Mediterranean region than the other parts of the world, and average temperature will increase by 1.4-5.8ºC globally, while the difference between current and projected temperature would be at least 3ºC for the Mediterranean region. As a result of this sharp rise in the mean annual temperature, a more drastic decrease in precipitation/rainfall is expected for the region [8]. WHO [9] reported that air pollution has become one of its top priorities since about 400,000 Eastern Mediterranean citizens died prematurely due to air pollution in 2012.

The Mediterranean background ground-level O₃ concentrations are the uppermost level in the Europe, and the O₃ concentration in the Central Mediterranean has been revealed to increase by a factor of five during the last century [12]. Gerasopoulos et al. [13] reported a significant decrease in the surface O₃ concentration at a rate of 3.1% per year based on observations on the Eastern Mediterranean between 1997 and 2004, which is attributed to the decreased O₃ precursor emissions transported in a long range from the Europe. Sicard et al. [14] showed from hourly O₃ data from 214 European background sites between 2000 and 2010 that rural background O₃ concentration is declining as a result of control measures taken, while corresponding urban concentration is still in an increasing trend. According to atmospheric transport model simulations, the enhanced summertime O₃ concentration over the Mediterranean basin is a major contributor to radiative forcing of the climate [15].

Once the fact that O₃ has been transported among the continents over a long range has been realized, O₃ pollution has become a global issue. The IPCC [8] estimated the global average surface O₃ concentrations for 2040, 2060, 2080 and 2100 at 35-48, 38-71, 41-87 and 42-84 ppb, respectively, based on the five of the less conservative emission scenarios. These future global projections have already been exceeded in the Central and Eastern Mediterranean regions, and Lelieveld et al. [11] demonstrated that the Mediterranean basin receives polluted air masses from the Europe and Asia which in turn deteriorates air quality and alters biogeochemical cycles in the region, in particular, over the summer periods. The long range transport of the air pollution to the Mediterranean has an adverse influence not only on the region itself but also further beyond the region. Therefore, urgent international actions are necessary to substantially decrease and mitigate the environmental pressures over the Mediterranean basin and to quantify and predict the anthropogenic change/alteration regime of the mechanistic relationships between the Mediterranean ecosystems and globally changing environment including climate change [16,17].

References

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3. Daly DG, Prance GT, Hammond, HD Campbell (1989) Brazillian Amazon. Floristic inventory of tropical countries New York Botanical Garden, Bronx, NY Pp: 401-426.
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