Saharan dust, agricultural field dust and automobile exhaust are among the primary sources of air pollution for the towns south of Lake Okeechobee, according to a study published in April by Florida A&M University and Tuskegee University.

On average, less than 1% of the particulate matter in air samples came from sugar cane burns, the study found. The highest level of sugar cane ash – less than 5% -- was found in a sample from a site near a burned cane field.

Researchers found the air quality in the “Glades” region stayed within the Environmental Protection Agency (EPA) National Ambient Air Quality Standards (NAAQS), even when sugar cane fields were burned.

University researchers met with officials from the Belle Glade, Clewiston, Pahokee and South Bay area at the Lawrence Will Museum on April 29 to review the study findings.

“Tuskegee University and Florida A&M University closely monitored the air quality in the Everglades and assessed the pros and cons of preharvest burning, specifically in regard to the regional economic and environmental impacts on the citizens of Palm Beach and Hendry Counties,” said Dr. Olga Bolden-Tiller, Tuskegee’s Dean of the College of Agriculture, Environmental and Nutrition Sciences. “We paid special attention to ensure that members of all of the communities in the region were represented and visited sugarcane production sites associated with U.S. Sugar.”

She said Tuskegee University and Florida A&M are land grant universities. “We understand communities are made of people,” she said. “Any concern that people have, we feel as a land grant institution, we have to answer that call.”

The first part of the experiment was to determine the level of particulate matter in the air, Bolden-Tiller explained. The second part was to determine what was in the particulate matter.

The researchers set up air quality monitors at six test sites in Clewiston, South Bay, Belle Glade, Pahokee and Loxahatchee. These sites included urban, residential and industrial areas, as well as the Gator Boulevard site near a sugar cane field, explained Dr. Gamal El Afandi of Tuskegee University.

He said they also conducted their own sugar cane burn tests on the farm at the university.

“It was important that we use our own data from our own equipment,” he explained. They found some peaks in particulate matter, but the air quality remained in the range EPA considers “good.”

The data was collected every minute of every hour, added Bolden-Tiller,

 Researchers found that the region’s air quality stayed within the Environmental Protection Agency’s National Ambient Air Quality Standards, including during sugar cane burns, with PM2.5 levels peaking for a few in May. PM2.5 refers to fine particles of 2.5 micrograms or less – about 3% the diameter of a human hair. According to the EPA, these fine particles can remain suspended in the air for extended periods and cane pose health risks when inhaled.

Researchers documented a spike in the particulate matter for three days in May 2024, with air in the “moderate” range while in the rest of the study period the air quality was in the “good” range.

The second part of the study involved examining the particulate matter.  Miller Environmental Solutions gathered the particulate matter using a variety of methods to collect airborne dust and particulate that lands on surfaces.

These samples were examined under an electron microscope at Tuskegee University to determine their source.

• Saharan dust was the influential source of up to 85% of particles in some samples, particularly during the three days in May when PM2.5 levels peaked. Saharan dust is a mixture of sand and mineral particles originating in North Africa. It is transported by winds to the Southern United States.
• Agricultural field dust, which includes soil, mineral dust, pollen and mold spores, was the source of 35 to 95%.
• Road dust accounted for 35 to 65%. This includes mineral dust, asphalt dust, silica dust, tire rubber dust and vehicle exhaust dust.
• Vehicle emissions were 10 to 65% of samples. These include carbon dust, palladium dust (from catalytic converters), oil droplets, iron oxides, sulfur oxides, nitrogen oxides and oil soot.
• Sugar cane ash was less than 1% in samples, with the exception of a sample taken at the cane field site, which had less than 5% sugar cane ash.
• Vegetative ash other than sugar cane was less than 1%.
• Pollen was 1%.
• Mold spores were 1 to 10%.

The researchers held community outreach sessions in the community to better understand key concerns, said Lucy Asare-Baah, also with Tuskegee University. “It was important for us to use a participatory approach.”

She said at one meeting, residents raised concerns about a foul odor in the area. The researchers discovered the source of the problem was the sewer system.

At the meeting, Bolden-Tiller responded to a question about fertilizer and pesticides that may burn with the sugar cane.

“Our data shows whatever particles rise in the air, they are not impacted at harmful levels,” she explained. Some of the burning is doing some good when it comes to different chemicals that may be a part of agriculture, she added, because the heat destroys them.

Bolden-Tiller said air pollution is a problem all over the world. “I visit countries where people have to wear masks like it’s covid,” she said.

“Science doesn’t lie,” she continued. “That’s why it’s so important that we have our land grant universities to do research.”

The study was conducted April 12 to Sept. 6, 2024. At the April 29. 2025 meeting, researchers were asked why they didn’t test October through March, when sugar cane burning is more active.

There was sugar cane burning in April and May, Miller explained. “We wanted to continue it June through September because we wanted to find out what is going on during those times.”

Bolden-Tiller said they also conducted sugar cane burn research at the university to compare to the results they found in the Everglades Agricultural Area.

Another meeting participant asked about the increase in cases of asthma in children. “That is not unique in this area,” said Bolden-Tiller. The national average has gone up across the entire country, even in areas where no sugar cane is grown, she added.

 “We have to look at all the different impacts that could be causing it,” she said. “If we don’t ask the question and do the research, we won’t know the answer. There are a lot of things contributing to these issues. It could be the environment. It could be other things.”

She said they would like to come back and do more research.

The full report is online at: www.tuskegee.edu\caens

Florida Forest Service regulates the preharvest burning of sugar cane in Florida. Burns are only allowed when there is no wind (so the ash will fall back on the fields) or winds will send ash into other cane fields, away from populated areas. Permits are given by 40-acre fields, for a 4-hour window on the day of the burn.

In 2024, a total of 4,557 burn permits were issued for sugar cane burns:

January: 636

Feburary: 565

March: 694

April: 605

May: 235

June: 0

July: 0

August: 0

September: 5

October: 388

November: 767

December: 662