Definition:
Aerosol:suspension of fine solid particles or liquid droplets in a gas. Examples are smoke, oceanic haze, air pollution, smog and CS gas. The word aerosol derives from the fact that matter "floating" in air is a suspension. (Wipedia)
Particulate Matter: are tiny subdivisions of solid or liquid matter suspended in a gas or liquid.
Redox potential (reduction potential): a tendency of a chemical species to acquire electrons and thereby be reduced.
Electrophile: electron lover- a substance that accepts an electron pair. Carbonyls and acids are examples.
quinone: a class of organic compounds that are formally derived from aromatic compounds.
Background: In other blogs, we have explained how particulate matter is a health hazard and the smaller or more fine the particulate the more likely it is to cause a heightened inflammatory response. There are several reasons for this but two important ones are because they have a larger surface area to bind with other contaminants and they are small enough to reach the deeper part of the lungs (if inhaled) or digestive tissue (if ingested) and infiltrate lower levels of tissue where they increase inflammation. Recently, a study of mice demonstrated how different strains have different basal levels of antioxidant genes that could potentially cause a increased or decreased risk for health consequences. In this case, it was a model for COPD which is an inflammatory respiratory disease and cigarette smoke. One can conclude from the results of this study and if the same is true for humans as it is for mice, different ethnic groups, lineages, etc. may be more susceptible than others to environmental contaminants. Interestingly, different mouse strains exhibit differences in basal levels of proinflammatory cytokines, oxidative stress and also expression of antioxidant genes Nrf2, HO-1, glutathione and others including IL-6. (Vecchio) These results augment controversial findings that suggest infections are less environmental than they are genetic and a person's susceptibility and ability to recover has to do less with environmental factors than it does genetics. (EurekAlert)
A few new studies shed a little bit more light on the chemical properties of PM and provides support for the idea that "semi-volatile and volatile contaminants have been implicated in causing adverse health effects. From this study, the author examined hazard levels in regards to the particle or vapor in an aerosol. He explains that redox-active components are particle-phase and vapors are more electrophilic and noted that latter contaminants were capable of inducing HO-1, a strong antioxidant and stress response protein. From this he concluded that volatile properties should be considered when determining the hazardous nature of a contaminant." While this may seem like greek to some, a general conclusion one can make from this is volatile properties of contaminants have adverse health effects. In addition, an investigator must be cognizant and consider genetic expression may influence a person's immune response to environmental contaminants including those that are volatile vapors.
Comment: The findings of these studies should have important influence on treatments descisions for MCS patients.
Vecchio, D., Arezzini, B., Pecorelli, A., Valacchi, G., Martorana, P. A. A., and Gardi, C. (2010). Reactivity of mouse alveolar macrophages to cigarette smoke is strain dependent. American journal of physiology. Lung cellular and molecular physiology. http://www.citeulike.org/user/HEIRS/article/6675046?show_msg=already_posted
Eiguren-Fernandez, A., Shinyashiki, M., Schmitz, D. A., Distefano, E., Hinds, W., Kumagai, Y., Cho, A. K., and Froines, J. R. (2010). Redox and electrophilic properties of vapor- and particle-phase components of ambient aerosols. Environmental research. http://www.citeulike.org/group/7769/article/6704033
(2010). Rockefeller scientist to speak at aaas on infections as genetic disorders.
http://www.citeulike.org/user/HEIRS/article/6704247
Shinyashiki, M., Eiguren-Fernandez, A., Schmitz, D. A., Di Stefano, E., Li, N., Linak, W. P., Cho, S.-H. H., Froines, J. R., and Cho, A. K. (2009). Electrophilic and redox properties of diesel exhaust particles. Environmental research, 109(3):239-244. http://www.citeulike.org/group/7833/article/6705178
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