Hearing and Performance During a 70-h Exposure to Noise Simulating the Space Station Environment

Introduction: Elevated hearing thresholds have been documented in some astronauts after long-term spaceflights although noise levels were lower than those normally associated with noise-induced hearing loss in ground-based operations. The present study was conducted to determine whether prolonged exposure (70 h) to levels (72 dBA) recorded on...

Long-term, low-level exposure of guinea pigs and marmosets to sarin vapor in air: Lowest observable effect level

Realistic scenarios for low-level exposure to nerve agents will often involve exposures over several hours to extremely low doses of agent. In order to expose animals to the lowest controllable concentrations of agent and to increase exposure times until a lowest observable effect level (LOEL) becomes measurable, a validated system was developed...

Human safety and pharmacokinetics of the CFC alternative propellants HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3,3-heptafluoropropane) following whole-body exposure

HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3,3-heptafluoropropane) are used to replace chlorofluorocarbons (CFCs) in refrigerant and aerosol applications, including medical use in metered-dose inhalers. Production and consumption of CFCs are being phased out under the Montreal Protocol on Substances that Deplete the Ozone Layer....

Pathological and immunological effects of respirable coal fly ash in male Wistar rats

In this study the effects of inhalatory exposure to coal fly ash on lung pathology and the immune system in rats were examined. Rats were exposed to 0, 10, 30, or 100 mg/m3 coal fly ash (6 h/day, 5 days/wk) for 4 wk, or to 0 and 100 mg/m3 for 1 wk, and for 1 wk followed by a recovery in clean air of 3 wk. A concentration-related increase in lung...

Inhalation toxicokinetics of soman stereoisomers in the atropinized guinea pig with nose-only exposure to soman vapor

The toxicokinetics of the four stereoisomers of the nerve agent C(±)P(±)-soman were studied in anesthetized, atropinized guinea pigs for nose-only exposure to soman vapor. During exposure the respiratory minute volume (RMV) and respiratory frequency (RF) were monitored. Blood samples were taken for chiral gas chromatographic analysis of the...

One-year time sequence inhalation toxicity study of vinyl chloride in rats. I. Growth, mortality, haematology, clinical chemistry and organ weights

Wistar rats were exposed to atmospheres containing 0 (control) or 5000 ppm vinyl chloride monomer (VCM), 7 h/day, 5 days/week, for a period of 52 weeks. After 4, 13, 26 and 52 weeks each time 10 rats/sex/group were killed and subjected to extensive examinations. The present paper deals with growth, mortality, haematology, clinical chemistry and...