Details:

Alternative Title:
Parathion -- inhalation and oral toxicity studies on rats and dogs
Corporate Authors:
Aberdeen Proving Ground (Md.).‏ Edgewood Area‏. Toxicology Division. ; National Institute for Occupational Safety and Health.
Aberdeen Proving Ground (Md.).‏ Edgewood Area‏. Toxicology Division. ; National Institute for Occupational Safety and Health. Less -
Description:
Handwritten on title page: “Parathion -- inhalation and oral toxicity studies on rats and dogs performed for NIOSH by Toxicology Division, Edgewood Arsenal, Aberdeen Proving Ground, Maryland, 89 pages.”

Acute and subacute oral and inhalation toxicity of ethyl parathion (56382) was studied in male Sprague-Dawley-rats crossed with Wistar-rats and male Beagle-dogs. Experimental animals received single acute or subacute doses administered over 6 weeks. Median lethal concentration (LC50) for rats in acute inhalation studies was 84.00 milligrams per cubic meter (mg/m3). The red blood cell (RBC) median cholinesterase activity inhibition concentration was 5.43mg/m3, and the plasma median cholinesterase activity inhibition concentration was 7.28mg/m3. Toxic signs included tremors, convulsions, salivation, respiratory difficulty, and death. Dogs were acutely exposed to concentrations ranging from 0.0153 to 37.13mg/m3. Cholinesterase activity was inhibited at all exposure concentrations. In acute oral studies, the LD50 for rats was 6.85mg/kilogram (kg), the RBC median cholinesterase activity inhibition concentration was 2.58mg/kg, and the plasma median cholinesterase activity inhibition concentration was 2.5mg/kg. Tremors, salivation, convulsions, prostration, and death were observed. In dogs, the acute oral LD50 was 8.27mg/kg, the RBC median cholinesterase activity inhibition concentration was 1.5mg/kg, and the plasma median cholinesterase inhibition activity concentration was 1.67mg/kg. Tremors, convulsions, and death were observed. In subacute inhalation studies, 0.01mg/m3 had no effects in rats, whereas doses of 0.10 and 0.74mg/m3 had moderate and pronounced effects, respectively. In dogs, 0.001mg/m3 subacute inhalation exposure had no effects, whereas 0.01 and 0.20mg/m3 had moderate and pronounced effects, respectively. In subacute oral toxicity tests the ethyl parathion concentrations producing no effect, moderate effects, and pronounced effects on RBC and plasma cholinesterase activity in rats were 0.05, 0.10, and 0.25mg/kg, respectively. The corresponding values in dogs were 0.05, 0.10, The authors suggest that human exposure levels can be predicted from observed effects on RBC or plasma cholinesterase activity.

NIOSHTIC No. 00134578


Subjects:
[+]
Animal-studies Biological-effects Clinical-symptoms Comparative-toxicology Dose-response Medical-research Mortality-data Physiological-response Toxic-effects
Document Type:
Report
Collection(s):
Stephen B. Thacker CDC Library collection
Main Document Checksum:
[+]
urn:sha256:02856246274899178d96d421a7fd5ad0af3f754ece4f28e2dac4e0c111aa09a5
Download URL:
https://stacks.cdc.gov/view/cdc/21994/cdc_21994_DS1.pdf
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