J Physiol. 2021 Nov 3. doi: 10.1113/JP282179. Online ahead of print.
ABSTRACT
KEY POINTS: Long-term exposure to elevated levels of atmospheric CO2 is an uncontrolled experiment already underway. This is the first known study to assess non-respiratory physiological impacts of long-term (conception to young adulthood) exposure of mice to CO2 at levels that may arise in the atmosphere due to global emissions. Exposure to elevated CO2 , in comparison to control mice, altered growth patterns in early life and resulted in hyperactive behaviours in young adulthood. Renal and bone parameters, which are important to balance acid-base levels to compensate for increased CO2 exposure, remained relatively unaffected. This work adds to the body of evidence regarding the effects of carbon emissions on mammalian health and highlights a potential future burden of disease.
ABSTRACT: Atmospheric carbon dioxide (CO2 ) levels are currently at 418 parts per million (ppm), and by 2100 may exceed 900 ppm. The biological effects of lifetime exposure to CO2 at these levels is unknown. Previously we have shown that mouse lung function is altered by long-term exposure to 890 ppm CO2 . Here, we assess the broader systemic physiological responses to this exposure. Mice were exposed to either 460 ppm or 890 ppm from preconception to 3 months of age, and assessed for effects on developmental, renal, and osteological parameters. Locomotor, memory, learning, and anxiety-like behaviours of the mice were also assessed. Exposure to 890 ppm CO2 increased birthweight, decreased female body weight after weaning, and, as young adults, resulted in reduced engagement in memory/learning tasks, and hyperactivity in both sexes in comparison to controls. There were no clear anxiety, learning, or memory changes. Renal and osteological parameters were minimally affected. Overall, this study shows that exposure of mice to 890 ppm CO2 from preconception to young adulthood alters growth and some behaviours, with limited evidence of compensatory changes in acid-base balance. These findings highlight the potential for a direct effect of increased atmospheric CO2 on mammalian health outcomes. Abstract figure. The aim of this study is to investigate how rising atmospheric carbon dioxide (CO2 ) levels affect mouse physiology. To achieve this, mice were exposed to either 460 ppm (standard housing conditions) or 890 ppm (may eventuate by 2100) from preconception to 3 months of age. Mice were assessed for effects on developmental, renal, osteological, and behavioural parameters. Exposure to 890 ppm CO2 increased birthweight, decreased female body weight after weaning, and, as young adults, resulted in reduced engagement in memory/learning tasks, and hyperactivity in both sexes in comparison to controls. There were no clear anxiety, learning, or memory changes. Renal and osteological parameters were minimally affected. Overall, this study shows that exposure of mice to 890 ppm CO2 from preconception to young adulthood alters growth and some behaviours, with limited evidence of compensatory changes in acid-base balance. While more work needs to be done, these findings highlight the potential for a direct effect of increased atmospheric CO2 on mammalian health outcomes. This article is protected by copyright. All rights reserved.
PMID:34731494 | DOI:10.1113/JP282179
Full Text Link: Read More