Whole body exposures to a phosphoric acids aerosol: I. Spontaneous activity effects in wild rodent and avian species.
Two inhalation-chamber studies were conducted to assess acute (2-h out-of-chamber) and subacute (< or = 6 d postexposure) spontaneous activity effects of whole-body phosphoric acids aerosol exposure(s) in black-tailed prairie dogs (Cynomys ludovicianus) and rock doves (Columba livia). The aerosol was generated using a red phosphorus/butyl rubber (RP/BR) mixture under development as a military obscurant. Each study involved (1) 3 RP/BR target concentration groups [0.0 (controls), 1.0, and 4.0 mg/L], (2) 24 prairie dogs or rock doves (8/group), with gender included as a factor, (3) a successive 3-phase paradigm (2 d preexposure; 4 and 2 d of about 80 min/d exposures to RP/BR for prairie dogs and rock doves, respectively; and 6 d postexposure), and (4) infrared detection of the rodents'/birds' home-cage movements. In-chamber atmospheres were uniform and acceptable for all exposures; median aerosol mass concentrations ranged from 0.76 to 0.89 mg/L and 3.46 to 3.74 mg/L for the 1.0 and 4.0 mg/L groups, respectively, with median phosphoric acid (H3PO4) readings of between 67.2 and 74.3%; median particles were < or = 0.85 microns. Mortality was negligible; no prairie dogs died, but 1 male rock dove died on d 3 postexposure to two 4.0 mg/L target concentrations of RP/BR aerosol. Group x session interactions were significant for the acute activity counts of both species. The acute mean ambulatory (e.g., walking) counts of prairie dogs and the acute mean ambulatory and horizontal (e.g., preening) counts of rock doves exposed to 4.0 mg/L RP/BR aerosol were relatively less than those of the other groups after the first 2 or 1 exposures, respectively. Nevertheless, acute session means for all groups approximated or exceeded the 23 h/d activity measured during the pre- and postexposure phases--data indicating that chamber confinement caused a temporary, sharp increase in activity for both species irrespective of RP/BR aerosol concentrations. No RP/BR concentration-related, subacute shifts in the activity of the rodents/birds were observed.
USDA/APHIS/ADC, Denver Wildlife Research Center, CO 80225-0266.
R T
RT
Sterner
D000280:Administration, Inhalation; D000336:Aerosols; D000704:Analysis of Variance; D000818:Animals; D010856:Columbidae / Q000502:physiology*; D005260:Female; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D010756:Phosphoric Acids / Q000008:administration & dosage / Q000633:toxicity*; D012589:Sciuridae / Q000502:physiology*
D000336:Aerosols; D010756:Phosphoric Acids