NEW ORLEANS — Dominique Thomas had to think hard to count all the people in her family who had developed Parkinson’s disease.
Three of her family members have died of complications related to Parkinson’s, she said. At least four others are living with Parkinson’s symptoms. Yet all have been reluctant to seek medical care.
Thomas’s family reflects two realities of Parkinson’s in Black communities, neurologists and advocates say. One, communities of color are disproportionately exposed to environmental pollutants, including pesticides and other chemicals linked to Parkinson’s. At the same time, some Parkinson’s experts worry that Black Americans are underdiagnosed for the disease.
Thomas is clinical coordinator for the Movement Disorder and Memory Division at Ochsner Health in New Orleans, part of a global research study on Parkinson’s and Black populations. Louisiana State University, the University of Florida and other medical centers are also working on research into novel genes, access to care and health disparities.
It’s not uncommon for Thomas’s African American patients diagnosed with Parkinson’s to reveal, “‘Oh, my grandfather, I think he really had Parkinson's disease,’ but they didn't talk about it,” Thomas said. “It was the hush-hush in the family. Maybe grandma knew, but didn't tell the family.”
Conventional medical wisdom has it that Black people are less likely to develop Parkinson’s. Black patients are diagnosed with the disease at half of the rate of white patients. But advocates and researchers stress that insurance access, under-reporting of symptoms and mistrust in healthcare could all help drive underdiagnosis.
Parkinson’s in the family
Thomas grew up in Raceland, Louisiana, a historic center of the state’s sugarcane industry. Those fields, like Florida's, were historically sprayed with paraquat, a weed-killer now known for its toxicity and association with Parkinson’s. She remembers running through the cane fields alongside friends, chopping a stalk, peeling back its skin and chewing on the sugary treat. They sometimes played in the crop dusters’ mist. They chased down mosquito trucks, too.
“Growing up, it's something normal…mosquito trucks coming down, and you hear it, zzzzz. And then it’s like ‘oh the truck’s coming guys, alright, we gonna run behind and make the little man blow his horn,’” Thomas remembered. “It’s the funny things like that, that you can remember doing and that was fun for us.”
What was fun as kids turned serious for Thomas as she grew up to see the burden of environmental exposure in her own family—and in her patients. Research identifies widespread disparities in exposure and harm from pesticides and other chemicals, with Black and other people of color bearing a disproportionate burden.
Thomas said her family, like many others, had limited options when it came to good job opportunities in rural Louisiana. Many of them went to work at the Monsanto chemical manufacturing plant in Luling, now owned by Bayer AG, which produces glyphosate, the active ingredient in the popular herbicide Roundup.
“This is a community thing. Your go-to place for where you wanted a job, where you were making money at. You go to school, get your degree, go work here as an engineer because they were paying great money, and where a lot of families were able to buy their first piece of land,” she said.
“So it was the company that you wanted to work for.”
Now, she can’t help but think about all the different potential exposures her relatives encountered: The cane fields. The mosquito trucks. The plant where they helped manufacture herbicide. Air pollution. The Bayer plant where numerous Thomas family members worked had the highest toxic releases of any facility in the state of Louisiana in 2024, according to the Environmental Protection Agency.
Researchers believe that a combination of factors may trigger the biological changes that ultimately lead to Parkinson’s, which can include a variety of exposures to chemicals and toxins. Throughout Thomas’s life, she’d see symptoms of Parkinson’s creep up on several of her family members: the shaking hands and stooped gait; later, being prone to falls.
She ultimately made it her career to help people with the disease.
Dominique Thomas of Ochsner Parkinson's Comprehensive Care Center in New Orleans highlights the environmental and cultural barriers keeping Black patients from participating in research studies and receiving proper diagnoses. (Emma Twombly/WUFT News)
Justice in Louisiana’s “Cancer Alley”
In St. James Parish between New Orleans and Baton Rouge, Pastor Harry Joseph described seeing fellow pastors develop Parkinson’s.
“I thought it was coming from preaching, we got a couple of pastors that got Parkinson’s and I said ‘man, he got it because he preached so hard,’” Joseph joked. “Other preachers were looking and saying, ‘That’s what he got it from, preaching hard.’”
“I said naw that’s not from the preaching,” said Joseph, the 71-year-old pastor of Mount Triumph Baptist Church of St. James Parish. “’I’m going to continue to preach hard.”
Joseph grew up in nearby Donaldsonville, which, like St. James Parish, lies in the heart of “Cancer Alley,” a stretch of the Mississippi River known for its high concentration of industry–and high rates of cancer and other illnesses.
Joseph became an environmental activist by virtue of where he lives, a region with some 200 fossil fuel and petrochemical plants that manufacture roughly a quarter of the nation’s petrochemical products. He wonders about how the pollution may have influenced his pastor friends’ Parkinson’s and his own Lou Gehrig’s disease.
Sharon Lavigne, 73, an environmental justice advocate and lifelong resident of St. James Parish, grew up in the rural region drinking crisp water from the lake in her backyard and eating fresh produce from her family’s garden. She’s been diagnosed with an autoimmune disease, and has watched people in her tight-knit community die of cancer. “Nobody takes accountability for what's going on over here,” Lavigne said.
“If we try to sue one, they gonna say they are not the reason, somebody else is the reason,” said Lavigne, who is part of a lawsuit against St. James Parish for directing hazardous industrial development toward Black-majority districts and churches.
“It's hurtful,” said Lavigne. “Y'all killing us, [and] we don't know who gonna be next.”
Residents and researchers detail the cost of chemical pollution — and why cleanup alone can never fully deliver justice to fence-line communities. (Emma Twombly/WUFT News)
“An actual white disease”
Back at Ochsner Medical Center in New Orleans, Thomas said a lot of her Black patients didn’t think Parkinson’s was a disease that affected them.
“‘We had no idea, we thought that this was an actual white disease,’” Thomas recalled patients telling her.
Belief that Parkinson’s symptoms are part of natural aging; racial biases held by practitioners; and stigma could all impact the low diagnosis rate among African Americans, according to research and movement-disorder specialists.
“It’s scary from the beginning, especially if you’re an active person. It’s a prideful thing, if [you’re] used to working in front of the public, and that’s probably why I’m not working—because of pride,” said Orien Greene, a retired mortician in Gainesville who is active in Florida’s Black PD Group. The fellowship group for Black people with Parkinson’s is organized by UF’s Norman Fixel Institute for Neurological Diseases, which is also involved in the global research study.
Greene said he has a genetic disposition for the disease. An estimated 15% of cases have a known genetic link. Researchers say some combination of genetics and environment play a role in who develops Parkinson’s. When he was young, Greene said, he worked from “dark to dark” on his family’s farm spraying pesticides. Then he spent his career as a mortician handling embalming chemicals. Both are known to increase risk of developing Parkinson’s. But a big part of the challenge now that he has it is the shame of having a disease that isn’t normalized in the Black community.
“I don’t want to be shaking like this, be on a walker in front of people,” Greene said.
Low clinical trial participation
Black Americans make up only 1.7% of Parkinson’s research trials, according to UCLA Health. In one study analyzing the 33 Parkinson’s trials reporting racial enrollment over 22 years, only 1% of all participants were African American. In another study examining the outcomes of Parkinson’s in non-whites, only 1.9%, or 162 of 8,514 participants, identified as African American.
Bernard Coley, 74, is caregiver to his wife, Denise Coley, who has Parkinson’s. He became an advocate for Black people with Parkinson’s shortly after she was diagnosed in 2018. The lack of Black people in Parkinson’s spaces was obvious.
Coley attributes lack of Black participation in clinical trials to the history of unethical medical experimentation on Black Americans, from times of slavery and beyond.
“The predominant subject of clinical research in the U.S. was done on Black people,” Coley said. “And we disappear from clinical research, except for a limited number of things, especially where you can imagine white people didn't want to be the subjects.”
The Coleys have diversified Parkinson’s spaces since stepping onto the scene. They engage Black communities across the country. They’ve published a storybook that highlights stories of Black people with Parkinson’s. They’ve worked with movement-disorders specialists to get more Black people involved in clinical trials.
Dr. Chantale Branson, a neurologist and assistant professor of medicine at the Morehouse School of Medicine in Atlanta, said she thinks the problem is with the medical community: “I think that Black people aren't being asked, they're not even in the room to have those conversations,” Branson explained. “I think they're just being overlooked because usually you need a referral to see the specialist in the first place, so somebody has to initiate that to get them in the room.”
Black people displaying signs of Parkinson’s might not be familiar with the disease and seek out specialists, said Thomas in New Orleans. Having someone like her to host educational sessions about the disease targeted at African Americans and stress the importance of participating in clinical trials helps, she said.
“A lot of people are like, ‘well, I don't want to be a guinea pig.’ That's the first thing all African American patients say,” she said. “So, I take that time…and then that makes them comfortable to be able to participate in research. Now they have a full-blown understanding of what research is. ‘Here's how you're making a difference,’ and then, typically, they bring other people back to come and participate in research.”
Living with “The Shakes”
Having Parkinson’s isn’t a death sentence, neurologists stress. But it can impair one’s way of life greatly, especially if left untreated. In addition to being less likely to be diagnosed, Black people are more likely to receive a delayed diagnosis, said Branson.
Once diagnosed, Black patients are less likely to be treated by a specialist, and to be prescribed Levodopa, one of the most effective drugs to treat Parkinson’s motor symptoms.
Others may not know of the different treatment options possible for Parkinson’s. In a study Branson conducted with Black participants, nearly 70% didn’t know of treatment options beyond their current regimen. Nor did they know about Deep Brain Stimulation, surgical placement of a pacemaker-like device in the brain to help control movement when medication isn’t enough.
Branson was inspired to dedicate her neurological career to studying Parkinson’s in Black people after her aunt developed the disease. She was diagnosed five years after displaying symptoms. Timely diagnosis, Branson said, is the most crucial denominator for quality of life. It’s also the biggest problem Black people face in their journey to proper treatment.
Like Branson’s aunt, Greene, the retired Gainesville mortician, lived with the symptoms of Parkinson’s for five years before he was officially diagnosed. Most diagnoses take a little under three.
Thomas, the New Orleans clinical coordinator, says she still runs into people every day who don’t understand or know what Parkinson’s is. “They consider it as ‘my family member has the shakes,’ or ‘my family falls a lot.’ “ With education, outreach and improved care, she hopes she can help change outcomes for them—and for her own reluctant family members.
“I want the public and everyone to understand,” Thomas said, “that your Black Parkinson's patients are there.”
This story is part of Poisoned Pathways, an investigation into chemical exposure and Parkinson’s disease supported by the Pulitzer Center and reported by the WUFT Environment & Ag Desk at the UF College of Journalism and Communications.
