The Prenatal Development Effects of Carbon Dioxide (CO2) Exposure in Rats (Rattus Norvegicus)
Abstract
Female rats were exposed to clean air or 1.5%, 2.0%, 2.5%, or 3.0% carbon dioxide (CO2) gas for ~23 hr/day from GD6-20 of pregnancy. There were no remarkable post-exposure findings in adults, including no differences in bodyweight or food consumption. There were no remarkable post-exposure findings in fetal bodyweight, and no malformations or developmental variations following CO2 exposure. There were two statistically significant findings in the 3.0% CO2 group: a higher mean post-implantation loss per litter (early resorptions) and a corresponding lower mean proportion of viable fetuses per litter. These results yield a No Observed Adverse Effect Level (NOAEL) of 2.5% and a Lowest Observed Adverse Effect Level (LOAEL) of 3.0% for CO2. Using the 2.5% NOAEL as a point of departure for a developing a CEL and an interspecies uncertainty factor of 3 yields a recommended CEL of 0.8% for CO2. Developmental endpoints are assumed to result from a single day of exposure during gestation; therefore, the 24-hour EEL is also recommended to be made 0.8% CO2. These recommendations should not outweigh any other studies that may derive a lower recommendation based on relevant data and endpoints.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 12, 2012
- Accession Number
- ADA583166
Entities
People
- Brian Wong
- Kimberly S. Bynum
- Michelle Okolica
- R. A. James
- William R. Howard
Organizations
- Naval Medical Research Unit Dayton