Increased CO2 levels could be risk to young lungs, Australian scientists find

Australian researchers have found that elevated levels of carbon dioxide in the atmosphere, in line with many climate predictions, could harm the development of young lungs, after observing the impacts of predicted conditions on mice.

In a world-first study, Australian scientists from the Telethon Kids Institute, Curtin University, The University of Western Australia and the Australian National University found that increased levels of carbon dioxide in the air had the potential to damage young lungs.

The research has been published in the journal Environmental Health Perspectives, and found mice experienced diminished young functions and greater difficulty breathing when raised in a high carbon dioxide environment.

The research team simulated an atmosphere with 900 parts per million of carbon dioxide, levels predicted to occur by the end of the century under many emissions scenarios, finding that it had a direct impact on both the lung function and lung structure of mice.

The scientists found that the impacts occurred throughout the life of the mice, including during pregnancy, early life, and into early adulthood.

“The lung damage included altered alveoli, which is the critical part of the lung that helps with gas exchange – meaning they could have had more difficulty breathing,” researcher associate professor Alexander Larcombe, a member of the Wal-yan Respiratory Research Centre, said.

“We also saw some changes in the actual physical structure of the lungs and both of these changes meant the lungs weren’t functioning as they should.”

Researchers said that the findings indicate that urgent and continued research into the impacts of elevated carbon dioxide levels was necessary.

“Current levels are just over 400ppm, and climate change modelling predicts that within our lifetimes it is likely to increase to about double that,” Larcombe added.

“There is a lot of research that looks at the environmental and health impacts of climate change, but none that focus solely on the health effects of breathing in higher levels of carbon dioxide in the atmosphere.”

The researchers found that the increased levels of carbon dioxide predominantly impacted younger lungs, and that there were no observed impacts on mice exposed to the higher concentrations once they had reached adulthood.

“This work has shown us that exposure to these predicted CO2 levels in pregnancy and early life is likely driving changes in lung function when the mice are adults. This therefore could be an opportunity to focus in on this period and help to protect lung development, and therefore improve the health outcomes later in life,” report co-author and University of Western Australia research Dr Caitlin Wyrwoll said.

“The lungs are the first organs that we would expect to see affected, and it gives us a clue that other systems in the body might also be affected.”

“We need to do further research into how it affects the respiratory system, as well as how the bones and the kidneys are developing, but also how the brain is working,” Dr Wyrwoll added.

Deputy Director of the Menzies Institute for Medical Research, Professor Graeme Zosky, said that the research revealed a new dimension to the potential impacts of increased greenhouse gas emissions.

“This is the first study to show a link between early-life exposure to future levels of atmospheric carbon dioxide and impaired lung growth. The findings of the study imply that the primary effect is on body growth and lung stiffness in females,” professor Zosky added.

“Early deficits in growth and lung stiffness are strong predictors of future risk for chronic lung disease and we know that these deficits are unlikely to improve later in life. This has implications for lung health in the community as carbon dioxide levels continue to increase in the coming decades.”

“This work adds to the growing body of evidence regarding the effects of carbon emissions on community health and shows that we need to act now to reduce the burden of disease in future generations,” professor Zosky added.

The scientists intend to continue the study over a longer period of time, to observe the impact of higher carbon dioxide concentrations on the development of other systems, including brain and kidney function.