Worldwide, the practice of preparing agricultural fields by burning crop residue contributes large quantities of gaseous pollutants and aerosol particles to the atmosphere and is a known cardiorespiratory health hazard. It has been shown that combustion byproducts in smoke cross the blood-brain barrier causing brain inflammation, and repeated inhalation of smoke can contribute to cognitive decline and dementia among older adults.
Federal efforts to monitor air quality have been focused on population-dense urban communities. As such, impacts of smoke exposure from agricultural fires on the risk of Alzheimer's disease and related dementias (ADRD) in rural populations are not well understood.
People who live in the rural communities along Lake Okeechobee are subjected to repeated, intermittent exposures to air pollution during agricultural fires. Not only is the risk of ADRD among aging residents of these communities from repeated air pollution a concern, but smoke exposure also is associated with an anxious, irritable and depressed mood, which could lead to social isolation and thereby impact mental health in general.
To better understand this issue, researchers from Florida Atlantic University have received a five-year, $4.2 million R01 grant from the National Institute on Aging of the National Institutes of Health (NIH) in collaboration with the University of Miami, Colorado State University and Washington State University.
The project, "The Role of Air Quality and Built Environment in Social Isolation and Cognitive Function Among Rural, Racially/Ethnically Diverse Residents at Risk for Alzheimer's Disease," will involve a total of 1,087 community-dwelling adults ages 45 and older who have not been previously diagnosed with ADRD from 50 neighborhood, block groups within five communities along Lake Okeechobee.
Lake Okeechobee is the largest freshwater lake in Florida and the second largest in the contiguous United States. The southern portion of the lake is rural, multiculturally diverse and home to sugarcane farmworkers whose social engagement wanes during agricultural burns. As socially vulnerable residents, they are at risk for ADRD because they lack access to resources available in urban settings.
An interdisciplinary team from nursing, social work, urban and regional planning, and epidemiology will examine the effects of smoke-related air pollution during agricultural burn and non-burn seasons on social isolation, cognitive function and risk of ADRD in rural residents at the southern end of Lake Okeechobee in Palm Beach County. As part of the study, researchers also will deploy easy-to-install, low-cost air pollution monitors in about 60 homes to assess ambient smoke levels.
For the study, the research team will gather electronic data using smartwatches in a subsample of 120 residents representing five Lake Okeechobee communities. The smartwatch subsample will be monitored for physical activity, social activity and cognitive performance. Biomarkers will provide passive continuous sensing of heart rate, respiratory rate, blood pressure, height/weight and calculated BMI.
"Our research team will use mobile devices and AI to explore how momentary changes in smoke from agricultural burns could lead to anxiety, depression and irritability, resulting in decreased physical activity, movement and social activity outside the home and in various built and social environments," said Lisa Kirk Wiese, Ph.D., principal investigator and an associate professor in FAU's Christine E. Lynn College of Nursing. "We will be gathering real-time data from our study participants that will provide detailed insights to immediate changes to behaviors and mood that occur when they encounter low air quality or distressed environments and how this translates to cognitive performance."
A key factor in this work has been the continuous engagement of rural community residents and organizations in the design, implementation and evaluation of research to decrease dementia risk.
Amyloid plaques and neurofibrillary tau tangles – a hallmark of Alzheimer's disease – can begin 20 years before any symptoms start to appear. Most research on Alzheimer's disease and related dementias targets older adults. Our study will include middle-aged adults when dementia risks begin to accelerate. As a result, we will be able to promote early awareness of the disease and earlier modification of the associated risk factors."
Christine Williams, DNSc, multi-PI and professor emeritus in FAU's Christine E. Lynn College of Nursing
Research co-investigators of the project include experts across various scientific fields: Janet Holt, Ph.D., an academic researcher in FAU's Christine E. Lynn College of Nursing; JuYoung Park, Ph.D., a professor in the Phyllis and Harvey Sandler School of Social Work, within FAU's College of Social Work and Criminal Justice; Diana Mitsova, Ph.D., chair and professor, Department of Urban and Regional Planning within FAU's Charles E. Schmidt College of Science; Lilah M. Besser, Ph.D., research assistant professor, Department of Neurology, University of Miami Miller School of Medicine; Sheryl Magzamen, Ph.D., associate professor, Department of Epidemiology, Colorado State University; Jeffrey Pierce, Ph.D., professor of atmospheric science, Colorado State University; and consultant Diane Cook, Ph.D., Regents Professor and a Huie-Rogers Chair Professor, School of Electrical Engineering and Computer Science, Washington State University.
"This study will provide evidence for the interactions between community and individual factors that heighten dementia risk in rural and diverse communities that face severe, adverse social determinants of health as well as high rates of this disease," said Safiya George, Ph.D., Holli Rockwell Trubinsky Eminent Dean and Professor, FAU Christine E. Lynn College of Nursing. "Importantly, the findings from this study will inform a mitigation model and public health interventions that will diminish the threat of Alzheimer's disease and related dementias in rural settings and ultimately improve quality of life and reduce health care expenditures."
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