Anthropogenic ozone

Anthropogenic ozone depletion is through catalyst reactions of the type... 

With the addition of Reactions 2-173 and 2-174, the production and consumption of ozone include both chain and parallel reactions. The method of solution is nonetheless similar to the case without anthropogenic ozone destruction. To solve for the concentration of [O3], it is necessary to solve for [XO], [O], and [O3] from three equations d[XO]/df=0, d[O]/df=0, and d[O3]/df=0. 

Pitts, J. N., Jr., Anthropogenic Ozone, Acids, and Mutagens Half a Century of Pandora s NO,., Res. Chem. Interned., 19, 251-298 (1993a). 

Portmann, R.W., S. Solomon, R.R. Garcia, L.W. Thomason, L.R. Poole, and M.P. McCormick, Role of aerosol variations in anthropogenic ozone depletion in polar regions. J Geophys Res 101, 22,991, 1996. 

Environmental Impact of Ambient Ozone. Ozone can be toxic to plants, animals, and fish. The lethal dose, LD q, for albino mice is 3.8 ppmv for a 4-h exposure (156) the 96-h LC q for striped bass, channel catfish, and rainbow trout is 80, 30, and 9.3 ppb, respectively. Small, natural, and anthropogenic atmospheric ozone concentrations can increase the weathering and aging of materials such as plastics, paint, textiles, and mbber. For example, mbber is degraded by reaction of ozone with carbon—carbon double bonds of the mbber polymer, requiring the addition of aromatic amines as ozone scavengers (see Antioxidants Antiozonants). An ozone decomposing polymer (noXon) has been developed that destroys ozone in air or water (157). 

Certainly, photochemical air pollution is not merely a local problem. Indeed, spread of anthropogenic smog plumes away from urban centers results in regional scale oxidant problems, such as found in the NE United States and many southern States. Ozone production has also been connected with biomass burning in the tropics (79,80,81). Transport of large-scale tropospheric ozone plumes over large distances has been documented from satellite measurements of total atmospheric ozone (82,83,84), originally taken to study stratospheric ozone depletion. 

The Antarctic ozone hole is the result of anthropogenic release of trace gases into the atmosphere (CFCs in particular), causing a decrease in stratospheric ozone and a subsequent increase in solar ultraviolet radiation reaching the earth s surface. 

Logan, J. A. (1985). Tropospheric ozone seasonal behavior, trends, and anthropogenic influences. /. Geophys. Res. 90,10463-10482. 

The extent to which this occurs depends on a number of issues (Finlayson-Pitts and Pitts 1997), including the reactivity of the hydrocarbon that is itself a function of many factors. It has been proposed that the possibility of ozone formation is best described by a reactivity index of incremental hydrocarbon reactivity (Carter and Atkinson 1987, 1989) that combines the rate of formation of O3 with that of the reduction in the concentration of NO. The method has been applied, for example, to oxygenate additives to automobile fuel (Japar et al. 1991), while both anthropogenic compounds and naturally occurring hydrocarbons may be reactive. 

Located several kilometres above the Earth s surface is the stratosphere. Here the ozone layer acts as a filter, protecting life on Earth from harmful low-wavelength ultraviolet radiation known as UV-C, which damages biological macromolecules such as proteins and DNA. In order to understand the effects of anthropogenic input into the stratosphere, the production and destruction of the ozone layer has been studied by a variety of photochemical models and experimental methods. 

It appears that between 15 and 35 km, the oxides of nitrogen are by far the most important agents for maintaining the natural ozone balance. Calculations show that the natural NO should be about 4 X 109 molecules/cm3. The extent to which this concentration would be modified by anthropogenic sources such as supersonic aircraft determines the extent of the danger to the normal ozone balance. It must be stressed that this question is a complex one, since both concentration and distribution are involved (see Johnston and Whitten [119]). 

Other gases with significant anthropogenic sources contribute to acid rain (NO and SO ), the reduction of the ozone layer (chlorofluorocarbons), nutrient transport (NHj... 

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