Nitrogen dioxide, association

Nitrogen Dioxide a gas (NOj) consisting of one nitrogen and two oxygen atoms. It absorbs blue light and therefore has a reddish-brown color associated with it. 

FAS is normally characterized by growth retardation, anomalies of the head and face, and psychomotor dysfunctions. Excessive consumption of ethyl alcohol may lead to malformations of the heart, extremities, and kidneys. Since consumption of ethyl alcohol is socially acceptable and prevalent even in pregnant women, the risks associated with the use of ethyl alcohol are remarkable. However, it should be kept in mind that there are several chemical compounds in tlie occupational environment that may also cause malformations even at low doses. The oc-cupationally-important known human teratogens include methyl mercury, ethyl alcohol, PCB compounds, tobacco smoke, lead, TCDD, 2,4,5- F, carbon monoxide, nitrogen dioxide, gasoline, and fluoride. 

Land/atmospheric interfacial processes which impact climate and biological activity on earth are illustrated in Figure 3. Emissions of carbon dioxide, methane, nitrogen dioxide, and chlorofluorocarbons (CFCs) have been linked to the transmission of solar radiation to the surface of the earth as well as to the transmission of terrestrial radiation to space. Should solar radiation be an internal process or an external driver of the hydrologic cycle, weather, and air surface temperatures Compounds of sulfur and nitrogen are associated with acidic precipitation and damage to vegetation, aquatic life, and physical structures. 

Intersociety Committee. Tentative method of analysis for nitrogen dioxide content of the atmosphere (Griess-Sahzman Reaction), pp. 329-336. In Methods of Air Sampling and Analysis. Washington, D.C. American Public Health Association. 1972. 

In one study,human subjects were tested in a controlled-environ-ment chamber with a high (summer) temperature and with ozone, nitrogen dioxide, and carbon monoxide as pollutants. Performance on a divided-attention task given at the end of the exposure period and the subjects heartrate variability (a potential psychophysiologic measure of attention) were evaluated. The subjects displayed a significant decrement in peripheral attention associated with increased ambient temperature. Effects attributable to pollutant gases were variable. 

Kagawa and Toyama in Tokyo followed 20 normal 11-yr-old school children once a week from June to December 1972 with a battery of pulmonary-function tests. Environmental factors studied included oxidant, ozone, hydrocarbon, nitric oxide, nitrogen dioxide, sulfur dioxide, particles, temperature, and relative humidity. Temperature was found to be the most important environmental factor affecting respiratory tests. The observers noted that pulmonary-function tests of the upper airway were more susceptible to increased temperature than those of the lower airway. Although the effect of temperature was the most marked, ozone concentration was significantly associated with airway resistance and specific airway conductance. Increased ozone concentrations usually occur at the same time as increased temperature, so their relative contributions could not be determined. 

There are many examples of second-order reactions for example, associations, addition reactions, etc. The decomposition of gaseous nitrogen dioxide (2NO2 2NO + O2) follows the rate law, -d[N02]/dr = fc[N02]. The binding of a hormone to a receptor protein is also second-order. 

A number of NO-derived reactive species can initiate lipid peroxidation, including nitrogen dioxide and, most notably, ONOO , which displays unique properties as a mediator of lipid oxidation. On a molecular basis, ONOO is a more potent lipid oxidant than hydrogen peroxide and, unlike H2O2, it does not require metal catalysis. The one-electron oxidants such as metals, as well as heme proteins and peroxynitrite, are assumed to play an important role in many diseases associated with oxidative stress. Heme proteins such as horseradish peroxidase (HRP) can produce alkylperoxyl radicals through two sequential... 

Nitrogen dioxide (N02) is a brownish irritant gas sometimes associated with fires. It is formed also from fresh silage exposure of farmers to N02 in the confines of a silo can lead to silo-filler s disease. The 2008 TLVs are shown in Table 56-1. 

The equilibrium mixture of nitrogen dioxide and dinitrogen tetraoxide is completely associated at —9°C to the latter form which is marginally endothermic (Allj (g) +9.7 kJ/mol, 0.10 kJ/g). Above 140°C it is completely dissociated to nitrogen dioxide, which is moderately endothermic (AHf (g) +33.8 kJ/mol, 0.74 kJ/g). 

Oxidant gases such as nitrogen dioxide and ozone have also been studied with regards to their role in the development of asthma. Both of these gases have been associated with asthma exacerbations (Pamia et al., 2002), have increased airway responsiveness to inhaled allergens in asthmatic subjects (Jenkins et al., 1999), and can produce inflammatory changes in the airways (Davies Devalia, 1993 Devalia et al., 1999). Asthmatic children exposed to exhaust emissions experience more symptoms and reduction in peak flow measurements and increased hospital admissions for asthma exacerbations (Wyler et al., 2000). 

Nitric acid is a strongly acidic, corrosive liquid that is produced by the oxidation of ammonia and subsequent reaction of the oxidation products with water. Pure nitric acid is colorless. The characteristic yellow-brown color generally associated with concentrated solutions is due to dissolved nitrogen dioxide.91... 

Pilotto, L.S., R.M.Douglas, R.G.Attewell, and S.R.Wilson. 1997. Respiratory effects associated with indoor nitrogen dioxide exposure in children. Int. J. Epidemiol. 26(4) 788—796. 

Most health effects associated with nitrogen oxides (NOjc) are attributed to nitrogen dioxide. The main source of NOx in homes can be traced to gas stoves and heaters, where combustion takes place to produce heat. The combustion first produces NO, which then oxidizes rapidly to N02. High levels of N02 (approximately 150 ppm) can be lethal, while concentrations in the range of 50-150 ppm can produce lung disease. Lower concentrations may lead to eye, nose, and throat irritation. 

The free radical nature of the nitric oxide molecule allows it readily to form association products with other free radicals. Both the nitroxyl radical (HNO) and nitrogen dioxide (NO2) may be regarded as simple association products of this type, and the high reactivities of both these species towards H, OH or O are able to produce several interesting and important effects when one of the two nitrogen oxides is added to, or formed in, the hydrogen—oxygen system. 

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