Do local environmental factors contribute to dementia? FAU nursing professors want to find out.

The phenomenon that locals refer to as “black snow”  – intermittent sugarcane burning that starts each October and ends as late as May – might not only be a problem for South Florida's air quality, but could have an impact on residents’ brain health.

Two professors from FAU's College of Nursing are leading a team of investigators from four other institutions to evaluate the relationships between social isolation, lack of built environment and intermittent sugarcane burning on brain health. Funding from the National Institutes of Health (NIH) is supporting this five-year study of largely rural farming communities surrounding Lake Okeechobee with a $4.2 million grant, FAU announced last August.

The professors, Dr. Lisa Kirk Wiese and Dr. Christine Williams, both of the Christine E. Lynn College of Nursing, are finding that more participants than expected have signed up for the study. Their team, which includes community-based research assistants and students, recruits rural residents ages 45 and up to study the intersection of multiple factors: lack of meeting places that support social engagement with seasonal sugarcane burning, in citizens facing increased risk of dementia over time.

The study currently being conducted in the Glades is called community-based participatory research. That means that residents of the studied community are involved in the planning, implementation and evaluation of the study. Thus far, since January of this year, more than 300 residents across five communities have participated in the study recruitment events, Wiese said, indicating that there is a high level of interest among rural residents.

Wiese also partners with Healthier Glades, which assists residents in the historically underserved rural areas of Palm Beach County – areas such as Belle Glade, Pahokee, South Bay and the unincorporated community of Canal Point – located in the western section of the county along Lake Okeechobee. Their overall mission, she says, is to help people in these communities cope with life’s stressors and promote better mental health and physical well-being. For about a decade, she has been providing health education, screenings and prevention programs in the Glades region. This community engagement has spurred research projects funded at the regional, state and national level.

A major focus throughout her research has been increasing awareness about Alzheimer's disease in this area, which lies in close proximity to farms that use sugarcane burning.

“We’d be out there, and there would be some black ash falling, or you’d smell the smoke. It would be really strong for a day, then it’ll be gone. But people said, ‘Oh yeah, when it’s like that, we just don’t go out, we don’t do anything. There’s not enough to do here anyway,’” Wiese explained in an interview. 

Wiese and William’s team is already aware that studies have shown a correlation between air pollution and the development of Alzheimer’s and other neurodegenerative diseases. However, they are investigating if adding in other factors also correlate to an increased risk. An individual's lack of social engagement, lack of built environment and amount of exposure to PM2.5 or fine particulate matter small enough to enter the lungs and bloodstream may all play a role. “Built environment” refers to places that foster human activity and interaction, such as parks, coffee shops and stores.

Wiese and her team are only in the beginning stages of this study. They expect to have results available beginning in 2028.

What’s unique about the air pollution in the Glades is that it’s intermittent. Researchers want to see if that specifically has an effect. For the study, air pollution levels will be matched with people’s mood, cognitive health and time spent outdoors. All of these factors will be measured twice a year. Researchers will see if anything changes over time. If anything does, they aim to pinpoint what led to those changes.

“We don’t want to stop any of the industries in the region. Farming is the vast majority of residents’ livelihood, and a mainstay of the economy. We do want to see if there are health-related issues stemming from the varied factors we are examining. If so, there are things we can do to help educate the residents to protect their health, and partner with the agricultural companies to adopt farming practices that protect health,” said Wiese. “The ultimate goal is to empower folks to age in place, and avoid early admission to a nursing home or other long-term care setting.”

Other Florida scientists and physicians have taken a keen interest in this issue.

Chang-Yu Wu is a professor of Environmental Engineering at the University of Miami. In 2012, the Palm Beach Department of Health hired Wu to conduct a study in which he and his team simulated the burning of sugar cane leaves in a combustion chamber and tested what pollutants were emitted. The pollutants that they studied are called PM2.5, or particulate matter with a smaller diameter than 2.5 micrometers. Wu said the minute size of these particles makes them dangerous.

Wu says brain inflammation and diseases like Alzheimer’s from this air pollution are possible.

“The pollutants get directly into the brain without going through the lung: it’s actually going through your nose. There is a channel that directly transports these pollutants to the brain,” he said. Research has shown that this air pollution is linked to cognitive decline, and new evidence has associated it with neurodegenerative diseases like Alzheimer’s and Parkinson’s disease.

“Really, there is no part of the body that is untouched by air pollution. It really causes head-to-toe harm,” said Dr. Ronald Saff, an asthma specialist, environmental activist and member of the nonprofit health advocacy group Physicians for Social Responsibility.

Saff explained that the real danger of this kind of air pollution is that the particles are ultrafine, allowing them to surpass the body's lines of defense. These particles can go right into blood vessels and cause blood clots, heart attacks, and even strokes.

“One of the most dreadful things I’ve ever seen is Rosenwald Elementary School,” said Saff. “It’s literally surrounded by sugar cane fields, and the Palm Beach County School District rents out that property to the sugar cane companies, and the sugar cane is being burned, you know, literally yards away from where school children are–many suffer from underlying asthma.” 

In 2008, there was an instance in which school children at Rosenwald were hospitalized with respiratory issues due to the thick smoke blowing into the school. Grist Magazine reported that six school children were hospitalized, and nine were treated by paramedics. 

According to Palm Beach County School Districts’ lease agreements, it is verified that the land surrounding Rosenwald Elementary has been rented out to U.S. Sugar for the use of growing sugar cane.

Health issues correlated to the agricultural practice of sugarcane burning have been seen in the local elementary school. Now, studies are underway to see if the pollution may have adverse effects on the elderly population and their risk of developing Alzheimer’s disease and other dementia-related conditions. 

The U.S. Sugar website cites a 2022 “State of Our Air Report.” It concludes that “Glades communities have air that is good, safe and clean,” according to Robert H. Buker, Jr., the company’s President & CEO. (Buker retired in October.) A press release last fall said that air in the Glades was cleaner than coastal areas.

Saff hopes for more national awareness of an issue that is often viewed through a hyper-local lens.

“It needs more national attention and maybe the EPA or Biden or Congress will do something,” said Saff. “But until then, it’s just tragic if you have to live in the Glades and inhale that deadly smoke.”