Inhalation toxicology
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Inhalation toxicology · Jan 2010
Upper airways sensory irritation responses of mice exposed to mainstream smoke from four cigarette types.
Relative sensory irritation responses for Swiss-Webster mice exposed nose-only to mainstream tobacco smoke were evaluated for several cigarette types using a smoking regimen consisting of a 35-ml puff, 2 s in duration, taken once per minute. The degree of sensory irritation for each cigarette type was evaluated as the smoke concentration inducing a 50% reduction in breathing frequency. The smoke concentration inducing 50% respiratory depression is called the RD(50) value. ⋯ This is indicative of reduced upper airways irritation by Eclipse that may be due to its distinct design. Study findings suggest that the irritating nature of mainstream tobacco smoke from different cigarette types can be evaluated effectively in terms of smoke concentration using the relative sensory irritation assessment. These findings constitute the first report about use of the RD(50) sensory irritation response during comparative evaluations of mainstream tobacco smoke.
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Inhalation toxicology · Dec 2009
Toxicological responses in SW mice exposed to inhaled pyrolysates of polymer/tobacco mixtures and blended tobacco.
Modern cigarette manufacturing is highly automated and produces millions of cigarettes per day. The potential for small inclusions of non-cigarette materials such as wood, cardboard packaging, plastic, and other materials exists as a result of bulk handling and high-speed processing of tobacco. Many non-tobacco inclusions such as wood, paper, and cardboard would be expected to yield similar pyrolysis products as a burning cigarette. ⋯ These responses were increased compared to exposure to tobacco pyrolysate alone. No moribundity or mortality occurred during the study. The data suggest that polymeric inclusions pose a minimal additional toxicologic hazard in humans.
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Inhalation toxicology · Dec 2009
ReviewHealth-based Provisional Advisory Levels (PALs) for homeland security.
The Homeland Security Presidential Directive #8 (HSPD-8) for National Emergency Preparedness was issued to " establish policies to strengthen the preparedness of the United States to prevent and respond to threatened or actual domestic terrorist attacks, major disasters, and other emergencies by requiring a national domestic all- hazards preparedness goal. "In response to HSPD-8 and HSPD-22 (classified) on Domestic Chemical Defense, the US Environmental Protection Agency (US EPA) National Homeland Security Research Center (NHSRC) is developing health-based Provisional Advisory Levels (PALs) for priority chemicals (including chemical warfare agents, pesticides, and toxic industrial chemicals) in air and drinking water. PALs are temporary values that will neither be promulgated, nor be formally issued as regulatory guidance. They are intended to be used at the discretion of risk managers in emergency situations. ⋯ Three exposure levels (PAL 1, PAL 2, and PAL 3), distinguished by severity of toxic effects, are developed for 24-hour, 30-day, 90-day, and 2-year durations for potential exposure to drinking water and ambient air by the general public. Developed PALs are evaluated both by a US EPA working group, and an external multidisciplinary panel to ensure scientific credibility and wide acceptance. In this Special Issue publication, we present background information on the PAL program, the methodology used in deriving PALs, and the technical support documents for the derivation of PALs for acrylonitrile, hydrogen sulfide, and phosgene.
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Inhalation toxicology · Dec 2009
Inhibition of immunological function mediated DNA damage of alveolar macrophages caused by cigarette smoke in mice.
Exposure to cigarette smoke impairs the pulmonary immune system, including alveolar macrophage function, although the mechanisms by which this occurs are not fully elucidated. This study investigates the effect of cigarette smoke exposure on the antigen-presenting activity of alveolar macrophages, which is required for antigen-specific response to T cells. C57BL/6 mice were exposed to cigarette smoke for 10 days using a Hamburg II smoking machine, and alveolar macrophages were obtained by bronchoalveolar lavage. ⋯ These results suggest that inhibition of the antigen-presenting activity of alveolar macrophages may result from decreased expression of major histocompatibility complex class II and B7-1 molecules and interleukin-1beta messenger RNA gene expression following cigarette smoke exposure. Furthermore, inhibition of antigen presentation in alveolar macrophage may result from DNA damage induced by excessive amounts of reactive oxygen species being generated by alveolar macrophages following cigarette smoke exposure. These findings suggest that cigarette smoke impairs the immunological function of alveolar macrophages and, as a result, increases the risk for pulmonary infection.
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Inhalation toxicology · Nov 2009
Comparative StudyA new tool for the early diagnosis of carbon monoxide intoxication.
Invasive measurement of carboxyhemoglobin (COHb) by blood gas analysis (BGA) is accepted as the standard diagnostic procedure in diagnosis of inhalation injury and carbon monoxide (CO) intoxications. The main disadvantage of BGA with COHb testing is the unavailability in pre-hospital rescue conditions. The non-invasive SpCO analysis using pulse CO oximetry (Rad57, Masimo Corp., USA) represents an easy-to-handle device to facilitate the diagnosis of CO intoxication. ⋯ When different blood gas analyzers in our department were tested with the same patient sample, a mean error of 2.4% was found. This is only 1% lower compared to the mean error of pulse CO oximetry. Therefore, pulse CO oximetry represents a reliable measurement technique that is easy to handle and could facilitate the early diagnosis of CO intoxication in pre-hospital rescue conditions.