Blue haze

Filter P per Processing. In the fabrication of fuel oil and air filters for vehicles such as motorcycles and diesel locomotives, heat processing of the filter paper is required to cure the resin (usually phenoHc) with which the paper (qv) is impregnated (see Phenolic resins). The cure-oven exhaust, which contains water vapor, alcohols, and dimers and trimers of phenol, produces a typical blue haze aerosol having a pungent odor. The concentration of organic substances in the exhaust is usually rather low. 

An extensive source of natural pollutants is the plants and trees of the earth. Even though these green plants play a large part in the conversion of carbon dioxide to oxygen through photosynthesis, they are still the major source of hydrocarbons on the planet. The familiar blue haze over forested areas is nearly all from the atmospheric reactions of the volatile organics... 

Thoiins Long-chain organic polymers responsible for the blue haze in the atmosphere... 

Despite the diverse chemical types represented by forest pesticides, the variety of their formulations, and the many rates and routes of application, two factors remain consistently present in their environment—sunlight and powerful reagents. Quite apparently, these forces are active and acting. The well-known "blue haze" observed over forests in many parts of the world remote from man s chemical wastes is a result of photooxidation reactions of volatile natural chemicals similar to those which generate manmade smog. 

Impurities in the drying atmosphere are exhausted in the air and have been referred to as "blue haze." One company has made substantial progress in collecting the blue haze emissions in a duct where they are directed through a series of water showers, filters and other equipment. Then the water is evaporated leaving a heavy liquefied residue which is collected on a stainless steel belt and deposited in storage vats. Currently this residue is being used as a fuel supplement, but some feel that it may be a future source for development of new chemicals. Apparently, this process meets Environmental Quality Standards with reference to air pollution. 

The meat was still pale. Beads of fat clung to it like sweat dipping through the mesh to splash hissing on the hot coals bebw. Thin cuds of smoke drifted lazi ip from them, scenting the air with a pungpnt blue haze. 

Ozonolysis of pinenes contributes to OH radical and SOA formation. The latter has been speculated to be responsible for the formation of "blue haze". Hence, it is of vital importance to quantitatively understand the roles of ozonolysis of a- and jS-pinenes on both OH and SOA formation in the troposphere. The O3 reaction with both pinenes follows the Criegee mechanism, similar to that of iso-prene. The initial step proceeds through cycloaddition of O3 to the C=C double bond of each pinene, forming a primary ozonide (POZ). The available reaction energy is retained as the internal energy of the product, resulting in formation... 

Isoprene, the common name for 2-methyl-1,3-butadiene, is given off by plants as the temperature rises, a process thought to increase a plant s tolerance for heat stress. Isoprene is a component of the blue haze seen above forested hillsides, such as Virginia s Blue Ridge Mountains. 

The biosphere is a major contributor to the atmosphere of heavier hydrocarbons. Fritz Went (8, 9), who first recognized the global extent of smog, pointed out the general importance of natural emissions from vegetation. He estimated that sources in the biosphere annually emit between 170 X 10 and 10 tons of hydrocarbon material to the atmosphere. Went also observed that these materials are mainly in the terpene class and that, because they are photochemically reactive, these materials are polymerized in atmospheric photochemical reactions to form an organic aerosol. He attributes the blue haze found in many forested areas to the optical effects of this aerosol. 

During the photooxidative reactions, aerosols are formed which are undoubtedly similar to the aerosols forming the blue haze over densely vegetated areas. This aerosol may also account for a significant quantity of the natural organic continental aerosol. 

All terpenes have one or more reactive double bonds. Reactions of terpene vapors in the presence of sunlight and air photochemically generate a blue haze over these forests when there is little air movement hence the name Blue... 

Last but not least come the environmental feedbacks that link atmospheric chemistry, the biosphere and climate change. Isoprene is a major biogenic trace component of the atmosphere. It was more than 40 years ago when Went (1960) discussed a specific relation between plant emissions and a blue haze observed above the countryside vegetation on sunny... 

Went (1960b, 1964) hypothesized that the blue haze often observed over forested regions is due to aerosols resulting from the photooxidation of terpenes and other organic compounds emitted from vegetation. Schwartz (1974) and Hull (1981) have studied particulate products from the oxidation of a-pinene. Schuetzle and Rasmussen (1978) have similarly studied limonene and terpinolene. Ring opening was observed in all cases. The products from a-pinene are shown in Fig. 7-17. The major products from... 

Went, F. W. (1960b). Blue hazes in the atmosphere. Nature 187, 641-643. 

Minus blue. Haze cutting in aerial photography, AAA. 45A... 

ACUTE HEALTH RISKS irritation of eyes, skin and respiratory system conjunctivitis comeal damage coughing nausea pulmonary edema destructive to tissues of mucous membranes "smoky vision" halo vision seeing "blue haze" difficult breathing loss of consciousness. 

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