As teenagers, David Toth and his sister grew up working at their dad’s dry-cleaning business in Rochester, N.Y.

Decades later both were diagnosed with Parkinson’s disease. Doctors told them it was likely linked to exposure to perchloroethylene (PCE), a chemical used for dry cleaning fabrics.

“You could smell it all the time,” says Toth, 74 years old, of Victor, N.Y., who was diagnosed with Parkinson’s in 2011. “I was around it quite a bit.”

Parkinson’s disease is the fastest-growing neurodegenerative disease in the world. But it’s also one of the most preventable, according to Dr. Ray Dorsey , neurologist at Atria Health and Research Institute in New York and co-author of a new book, “The Parkinson’s Plan: A New Path to Prevention and Treatment.”

A progressive nervous-system disorder, Parkinson’s primarily impacts movement. As dopamine-producing brain cells die, movement becomes affected, resulting in tremors, muscle stiffness, slowed movement and impaired balance.

Some doctors like Dorsey say most cases appear to be caused by environmental factors. A study in the journal Brain last year found that only 13% of Americans carry a genetic risk factor for the disease.

“The vast majority of Americans have no known genetic cause or risk factor for their disease,” says Dorsey. “So the principal cause of disease lies not with us, but outside of us, in our environment, in chemicals in our food, water and air.”

Other doctors say conversations about preventing Parkinson are missing the mark.

“We’re very much oversimplifying if we say ‘If we just get rid of that particular pollutant we are going to prevent Parkinson’s,’ ” says Dr. Brad Racette , chair of neurology and senior vice president at Barrow Neurological Institute in Phoenix. “We will probably have a measurable effect on the number of cases, but I think the key message is it’s not as simple as a single pollutant is causing an individual’s Parkinson’s.”

And Dr. Rodolfo Savica , a professor of neurology at the Mayo Clinic in Rochester, Minn., says there are a number of environmental and genetic factors that increase the risk of Parkinson’s disease.

“Increasing the risk doesn’t mean it will cause the disease,” says Savica.

“It’s fair to say that as of today we can potentially modify, identify and change some of the environmental exposures that we know can be a risk,” he adds. “But not everything can be explained solely by the environmental factors.”

While the debate over causation plays out, it is worth considering some of the ways that doctors like Dorsey recommend to potentially reduce your risk of developing Parkinson’s disease.

* Research the area near your home. Try not to move to an area near a golf course or Superfund site. A May JAMA Network Open study found that people who live within one mile of a golf course have a 126% increased risk of developing Parkinson’s.

Golf courses use high amounts of pesticides, like chlorpyrifos, which have been linked to Parkinson’s. The federal government banned the use of the weedkiller paraquat on golf courses in 2021.

While some states have banned or put restrictions on the use of chlorpyrifos on golf courses, it’s still allowed in some places. So check with area golf courses to find out what pesticides they use.

Superfund sites aren’t well marked, but you want to avoid living too close to one since toxic chemicals leak into the soil and eventually the surrounding air. The Environmental Protection Agency has a database to search for sites and environmental firms can test your air.

* Minimize exposure to dry-cleaning chemicals. The federal government is phasing out the use of PCE in dry cleaning, with a full phaseout by 2034. Most uses of another chemical, trichloroethylene (TCE), are banned.

Check to see what your dry cleaner uses and look for one that uses alternative cleaning methods. Be especially cautious if you live in a building above a dry cleaner. Studies have found unsafe levels of chemicals in the air of such homes.

TCE is a known carcinogen so also a risk factor for developing cancer. PCE is considered a likely carcinogen.

If your cleaner uses a PCE cleaning agent, air out your clothes somewhere like the garage for a day before bringing them home to avoid breathing in the chemicals.

* Air pollution is another risk factor . Air quality is something largely out of our control and dependent on government regulations, Racette says. He recommends lobbying your local representatives to take measures to better regulate potentially harmful chemicals.

“Do whatever you can to improve indoor air quality,” he says.

Dorsey recommends using an air purifier, particularly if you live in an urban area. Make sure the purifier has carbon filters that remove volatile organic chemicals.

* Drink clean water. If you drink water from a private well, it’s not regulated by the Safe Drinking Water Act. This means it could be contaminated.

Such wells tend to be in rural areas near farms where pesticides can wash off into groundwater, Dorsey says.

Be sure to test your well for pesticides and chemicals. There are mail-in tests. The EPA also has a list of certified laboratories that test water.

A carbon water filter can also reduce potential exposure to chemicals and pesticides that may have leached into your water. You can install under-sink or faucet filters. Even using a filter on a water pitcher works.

* Try to minimize overall pesticide exposure. Paraquat is a herbicide commonly used on farms and in yards for weed control. It is banned in many countries, but not the U.S.

Some studies have found links between long-term exposure and an increased risk of Parkinson’s disease, though evidence is mixed. And such studies can only show associations, not prove causality. Still, doctors and researchers say it’s toxic and best to avoid.

“Be careful what you’re spraying on your grass,” says Dorsey.

Write to Sumathi Reddy at Sumathi.Reddy@wsj.com