Is polluted air escalating dementia rates?

Antonella Zanobetti was engaged in pioneering research to investigate connections between exposure to environmental elements, like pollution and heat, and severe neurological and cardiovascular illnesses. However, three of her studies were paused due to the Trump administration’s widespread termination of Harvard research grants in May.

Initial evidence indicates that air pollution negatively affects the brain, stated Zanobetti, an environmental epidemiologist and principal research scientist at the T.H. Chan School of Public Health. She anticipated that her studies would enhance understanding of possible correlations between exposure and augmented risk of dementia, as well as assess the protective effects of modifiable risk factors like green space.

“It is essential to complete all the projects we are undertaking,” remarked Zanobetti, who directed a team of researchers in 2020 to carry out the first national investigation on the impact of air pollution on Alzheimer’s and Parkinson’s. “We must comprehend the elements that could influence hospitalization for neurological ailments. The high incidence of neurodegenerative diseases is a significant public health concern.”

Driven by aging populations and industrial activities, neurological conditions are escalating across the nation and worldwide. Alzheimer’s disease ranks as the sixth leading cause of mortality in the U.S., and the death toll for Parkinson’s is increasing rapidly. The global tally for individuals with Parkinson’s is anticipated to surpass 12 million by 2040.

“It’s vital to comprehend the influence of environmental factors on neurological disorders to aid in crafting public health policies.”

For one of Zanobetti’s suspended studies, her team was reviewing Medicare and Medicaid claims to gauge how long-term exposure to air pollution might elevate hospital admissions for Alzheimer’s and associated dementias. “We intended to explore whether air pollution exposure heightens mortality risk and/or accelerates rehospitalization,” she explained.

Gathering the data proved challenging since, when patients with Alzheimer’s or Parkinson’s are hospitalized, their neurodegenerative condition is often not the primary cause. “It could be a stroke or a fall,” Zanobetti clarified. “We were in the process of developing techniques to address statistical hurdles, including outcome misclassification, alongside investigating the influence of heat on hospitalizations.”

An additional study, co-directed by Danielle Braun, aimed to analyze the effects of heat and various environmental factors on hospitalizations for Parkinson’s and was expected to have two further years of funding when it was halted.

“We were in the midst of examining the effects of elevated temperatures and other air pollutants on Parkinson’s-related hospital admissions,” stated Zanobetti. “Our goal was to quantify both the chronic and acute impacts of multiple environmental exposures to comprehend how air pollution, heat, or other exposures affect hospitalization for Parkinson’s.”

Zanobetti faced the loss of a third grant. Co-directed by Petros Koutrakis, this study was set to be the first to demonstrate the effects of particle radioactivity on cardiovascular disease, which is the leading cause of death in the U.S.

Particulate matter, or minuscule particles of air pollutants, can be inhaled and penetrate the lungs, heart, and brain, noted Zanobetti. Particle radioactivity arises from radionuclides in the atmosphere that cling to fine-particle pollution and, once inhaled, emit ionizing radiation within the body.

The Environmental Protection Agency has leveraged prior research conducted by Zanobetti and her team on the health impacts of particulate matter to lower National Ambient Air Quality Standards for fine particulate matter, aiming to mitigate health hazards associated with air pollution. Last year, her research, along with that of other T.H. Chan School of Public Health scientists, contributed to the establishment of more stringent federal regulations on particulate pollution.

In summary, Zanobetti’s three terminated grants aimed to furnish scientific proof of the relationships between environmental factors and Alzheimer’s, Parkinson’s, and heart disease, intending to guide the creation of policies that would enhance air quality and safeguard public health, she remarked.

“It’s crucial to grasp the role of environmental exposures in neurological disorders to facilitate the development of public health policies,” asserted Zanobetti. “It’s genuinely disheartening to witness everything we labored for come to a standstill. There is so much left to explore, so much to learn, and we are unable to pursue it.”