Synergism smoke

Listing gaseous emissions, concentrations, smoke characteristics prevailing winds and exposed zones toxicity or nuisance potential effects of synergism or poor atmospheric dispersing conditions. Consent limits. 

A number of studies of the toxicity of zinc oxide/hexachloroethane smoke have been conducted (Brown et al. 1990 Karlsson et al. 1986 Marrs et al. 1983). These studies demonstrate that smoke exposure results in pulmonary inflammation and irritation. When male Porton Wistar rats were exposed to hexachloroethane/zinc oxide smoke for 60 minutes, the lungs showed pulmonary edema, alveolitis, and areas of macrophage infiltration 3 days later. At 14 days, there was interstitial fibrosis and macrophage infiltration. At 28 days, increased fibrosis and macrophage infiltration were noted. However, these same symptoms occurred when the animals inhaled zinc chloride there was no apparent synergism between the zinc chloride and residual hexachloroethane (Brown et al. 1990 Richard et al. 1989). This is consistent with the fact that smoke contains little hexachloroethane and the observation that acute exposure to 260 ppm hexachloroethane had no effects on the lungs of rats (Weeks et al. 1979). 

When two compounds exert the same action by acting at different sites, their interaction will often result in a synergistic effect but a simple additive effect is also a possibility (the synergism between smoking and asbestos exposure is the classical example). 

Saric M, Lucic-Palaic S Possible synergism of exposure to airborne manganese and smoking habit in occurrence of respiratory symptoms. In Walton WH (ed) Inhaled Particles, rV pp 773-779. New York, Pergamon Press, 1977... 

The combination of melamine with hydrated mineral fillers can improve the fire retardancy behavior of PP, eliminating at the same time the afterglow phenomenon associated with these fillers used in isolation.70 Similarly in EVA copolymer, antimony trioxide used in combination with metal hydroxides has been reported to reduce incandescence.56 Chlorinated and brominated flame retardants are sometimes used in combination with metal hydroxides to provide a balance of enhanced fire-retardant efficiency, lower smoke evolution, and lower overall filler levels. For example, in polyolefin wire and cable formulations, magnesium hydroxide in combination with chlorinated additives was reported to show synergism and reduced smoke emission.71... 

The human data, as well as the animal studies indicate that cannabinoids may ameliorate some symptoms of MS. Unfortunately, a definitive large-scale study has yet to be performed. Such a study should take into account that (a) the placebo effect in MS is very high (b) the effective doses recorded are close to, or identical with the doses that cause cannabimimetic effects (c) cannabis (marijuana, hashish) is obviously not identical to zf9-THC, and that other constituents may synergize THC action (d) smoking cannot be compared with oral administration, and (e) the anal route of administration [141] may be a preferred one. 

Tobacco smoke. Tobacco smoke produces particulate matter that acts as an adsorption site for toxic vapors)26 In addition to particulates, tobacco smoke produces more than 4000 individual toxic compounds, including 43 known carcinogens. 27 Many of the toxic effects of tobacco smoke that have been established empirically cannot be ascribed to individual compounds in that smoke. With more than 4000 different toxins, the number of mixtures possible is incalculable. Numerous examples of synergism between tobacco smoke and other toxicants have been identified. These include tobacco smoke and asbestos or other mineral fibers, I28 29 alcohol, I30 31 organic solvents, 32 biological... 

Tobacco smoking alone greatly enhances the risk for coronary heart disease (CHD) J44l Smoking and elevated serum cholesterol level synergis-tically increase the levels of CHD observed. 61 No mechanism for the synergism was proffered by the study. 

Coke oven workers are at risk for developing chronic obstructive pulmonary disease (COPD). There is a dose-dependent relationship between exposure to the benzene soluble fraction of coke oven emissions and COPD. Smoking in coke oven workers synergistically increases the incidence of COPD.1621 Though many of the compounds in cigarette smoke are identical to those in coke oven emissions, that alone cannot account for the observed synergism. 

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