Low level exposure to GB vapor in air: Diagnosis/dosimetry, lowest observable effect level (LOEL) and lowest observable adverse effect level (LOAEL)
conference paper
The purpose of the present study was to establish for both saline-pretreated and pyridostigmine-pretreated conscious guinea pigs whole-body exposed to low levels of GB vapor:
(i) The Lowest Observable Effect Level (LOEL) for GB, i.e., the C.t-value (t = 5-h) of exposure at which an internal dose (fluoride-regenerated GB from blood ChE) becomes measurable.
(ii) The Lowest Observable Adverse Effect Level (LOAEL) for GB, i.e., the C.t-value (t = 5-h) of exposure at which effects start to affect performance.
(iii) Whether unexpected adverse effects on performance emerge through the combination of pyridostigmine-pretreatment and GB exposure.
Read-out parameters reflecting adverse effects on performance during exposure were pupil size (miosis), EEG, visually evoked response (VER), and 1-h after exposure startle-response and shuttle-box active avoidance behavior. The lowest exposure concentration of GB which resulted in significant (p < 0.05) effects on these parameters by the end of a 5-h exposure period was taken for calculating the LOAEL (C.t-value) for each of these parameters. The averaged LOEL for saline-pretreated guinea pigs was 0.010 ± 0.002.0 mg.min.m-3 (t = 84 ± 17 min) which did not differ significantly from that of pyridostigmine-pretreated animals (0.014 ± 0.002.0 mg.min.m-3).
These data were addressed in the light of the recommended occupational limits for GB vapor in air.
(i) The Lowest Observable Effect Level (LOEL) for GB, i.e., the C.t-value (t = 5-h) of exposure at which an internal dose (fluoride-regenerated GB from blood ChE) becomes measurable.
(ii) The Lowest Observable Adverse Effect Level (LOAEL) for GB, i.e., the C.t-value (t = 5-h) of exposure at which effects start to affect performance.
(iii) Whether unexpected adverse effects on performance emerge through the combination of pyridostigmine-pretreatment and GB exposure.
Read-out parameters reflecting adverse effects on performance during exposure were pupil size (miosis), EEG, visually evoked response (VER), and 1-h after exposure startle-response and shuttle-box active avoidance behavior. The lowest exposure concentration of GB which resulted in significant (p < 0.05) effects on these parameters by the end of a 5-h exposure period was taken for calculating the LOAEL (C.t-value) for each of these parameters. The averaged LOEL for saline-pretreated guinea pigs was 0.010 ± 0.002.0 mg.min.m-3 (t = 84 ± 17 min) which did not differ significantly from that of pyridostigmine-pretreated animals (0.014 ± 0.002.0 mg.min.m-3).
These data were addressed in the light of the recommended occupational limits for GB vapor in air.
TNO Identifier
526830
Source title
BioScience 2000, US Army Medical Defense Bioscience Review, 4-9 June 2000
Pages
463-482
Files
To receive the publication files, please send an e-mail request to TNO Repository.