Population aging and economic conditions can amplify the health effects of air pollution

UNIVERSITY PARK, Pennsylvania — An aging population and setbacks in economic development could outweigh the health benefits of lower air pollution and slowing climate change, according to a team of researchers led by the Penn State which examines air quality and the factors most likely to impact future premature deaths.

The team used past and projected data to model five future scenarios by estimating premature deaths from air pollution and identifying the regions of the world that could be most affected. They published their findings today (October 24) in the journal Nature Sustainability.

“When we think about the impacts of pollution on future populations, exposure to ambient particulate matter – or air pollution – caused by fossil fuel emissions, is the greatest threat to global health,” he said. said lead researcher Wei Peng, assistant professor of civil and environmental engineering. at Penn State College of Engineering and International Affairs at Penn State School of International Affairs. “The burden of health is unequally distributed between countries and borne disproportionately by countries in the South. To make credible projections of future global health, we created an integrated modeling framework that combines air quality simulations with macro-level socio-demographic factors like global population and economic development.

The researchers integrated data from the World Climate Research Program Scenario Model Intercomparison Project with the National Oceanic and Atmospheric Administration (NOAA) Geophysical Fluid Dynamics Laboratory to estimate how changing socio-economic trends and climate mitigation efforts may influence global fossil fuel use and resulting air quality.

The resulting model estimated pollution exposure levels and the number of premature deaths with varying values ​​of pollution control, socio-economic trends and global warming over the years 2015 to 2100. In the five scenarios , the researchers found countries and regions that were limiting emissions and had declining fossil fuels. use had lower pollution concentrations.

However, lower pollution concentrations alone did not necessarily reduce the predicted number of deaths. According to Peng, aging and declining baseline mortality — the natural death rate unrelated to air pollution — were better predictors of premature death than exposure to air pollution alone.

“Emerging markets like China and India contribute less than half of global carbon emissions, but they suffer 60% of global health damage from air pollution,” Hui said. Yang, a Penn State doctoral candidate in civil and environmental engineering and first author on the paper. “It’s partly because they don’t have enough end-of-pipe controls or effective regulations controlling how much emissions industries can put into the air.”

In most future scenarios, China and India represent the highest estimated premature death numbers, the researchers found. Peng said this is likely the result of higher exposure rates due to lack of controls, combined with an aging population that is more vulnerable to pollution exposure.

“Areas with poor socioeconomic conditions and limited access to health care tend to have higher baseline mortality rates,” Peng said. “If you couple that with an aging population, death rates go up. If we do more to clean the air and limit emissions, we have a chance for a different future, to combat some of the negative health effects of coming socio-demographic changes.

Co-author Dan Westervelt, assistant Lamont Research Professor at Columbia University, said their modeling framework can inform societies’ next steps to mitigate the impacts of air pollution.

“Understanding the potential pathways of future air pollution and the associated health burden using Earth system models is key to developing effective mitigation strategies,” he said. “This work sheds new light on disentangling the impacts of emissions, climate change, exposure levels and demographic factors to determine the future health burden of air pollution.

Other co-authors include Xinyuan Huang of Penn State’s Department of Civil and Environmental Engineering and Larry Horowitz of NOAA’s Geophysical Fluid Dynamics Laboratory.

The National Science Foundation and a seed grant from the Penn State-Monash Collaboration Development Fund supported this work.