Low Level Exposure to GB Vapor in Air: Diagnosis/Dosimetry, Lowest Observable Effect Levels, Performance-Incapacitation, and Possible Delayed Effects
Abstract
The purpose of this effort was to re-monitor EEG-signals of vehicle or pyridostigmine- pretreated marmosets during a 5 h air-exposure in Nov. 2001 under experimental conditions similar to those in Nov. 2000 when they were first 5 h exposed to air followed by 5 h exposure to low levels of GB vapor in air in a concentration range of 7.5 - 150 micron/m3. The EEG-records were analysed by using Fast Fourier Transforms (FTT) in order to quantify the power spectra of the different frequency bands and by visual examination of the raw signals to quality typical clinical effects. In Nov. 2000 there were significant (p < 0.05) charges in most of their EEG-bands during GB exposure compared to corresponding bands during previous air-exposure, the AChE-activity in blood samples was significantly inhibited, and one hour after exposure disturbances in memory and motor function were observed. The LOAEL (C.t) values for significant changes in EEG-bands were 0.2 for d2 and b2 bands) and 0.1 mg.min.m-3 (for t1 band) for vehicle or pyridostigsnine- pretreated marmosets, respectively. During as h air-exposure in Nov. 2001 all marmosets still demonstrated EEG-bands which differed significantly (p <0.05) from corresponding bands during air-exposure one year earlier. in most vehicle-pretreated marmosets the energy (micronV2) per EEG-band was higher than that observed one year earlier. This phenomenon was less pronounced in pyridostigmine-pretreated animals. Visual examination of the EEG-records revealed clear bursts of alpha frequencies (around 9 Hz), so-called sleep-spindles which were more frequently present in pyridostigmine- pretreated GB exposed animals and in the vehicle pretreated animals exposed to 7.5, 25 or 150 microng/m3 GB
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2002
- Accession Number
- ADA400785
Entities
People
- Herman P. Helden
Organizations
- Prins Maurits Laboratorium TNO