- Nearby industrial water pollution facilities were associated with an increased risk of developing progressive supranuclear palsy (PSP), a rare brain disease.
- Heavy metals, pesticides, and organic and inorganic pollutants showed significant risk associations.
- PSP risk declined with distance, while longer residence near facilities increased risk.
People living near industrial facilities that polluted the water supply were more likely to develop progressive supranuclear palsy (PSP), a rare and severe neurodegenerative tauopathy, a study of U.K. Biobank participants showed.
PSP risk was linked with proximity to facilities that emitted heavy metals (OR 1.38, 95% CI 1.03-1.85), pesticides (OR 1.66, 95% CI 1.12-2.46), other organic pollutants (OR 1.52, 95% CI 1.13-2.04), and other inorganic pollutants (OR 1.60, 95% CI 1.19-2.15), reported Charlie Weige Zhao, MD, of Harvard Medical School in Boston, and co-authors.
The risk of PSP decreased as the distance from the facilities increased, the researchers wrote in Neurology. “There is also evidence that the length of time people lived near the polluting facilities played a role in their risk of PSP,” Zhao said in a statement.
“Diseases like PSP have causes. The gene contributions to PSP are modest. Instead, environmental factors likely contribute to this disease, which was first described just over 60 years ago,” Ray Dorsey, MD, of Atria Research and Global Health Institute in New York City, who wasn’t involved with the study, told MedPage Today.
“Zhao and colleagues have highlighted that environmental toxicants — metals and pesticides, for example — linked to other neurodegenerative disorders may be playing a role in PSP,” said Dorsey, co-author of “The Parkinson’s Plan,” a book proposing that Parkinson’s disease may be primarily environmental in origin.
“This PSP study also suggests that exposure via water or ingestion may be important,” he added. “More research like this and in the lab is needed to identify the causes of this terrible disease so it can be prevented, slowed, and treated.”
PSP is a movement disorder characterized by parkinsonism, eye movement abnormalities, and balance problems. There currently is no treatment that effectively stops or slows its progression.
Previous work by Zhao and co-authors did not implicate air pollution in the U.K. Biobank study cohort, but water pollution was not measured.
In the current study, the researchers compared incident PSP cases and matched controls in the prospective U.K. Biobank cohort by baseline residential proximity to European Pollutant Release and Transfer Register (PRTR) facilities.
Facilities included wastewater treatment plants, intensive aquaculture, chemical plants, and thermal power stations. Pollutants were classified as heavy metals, chlorinated solvents, persistent organic pollutants, pesticides, other organic pollutants, or other inorganic pollutants.
Incident PSP diagnoses were identified during 2007 to 2025. PSP cases were matched 1:10 with controls who did not have a diagnosis of parkinsonism or dementia.
The analysis included data from 221 PSP cases and 2,249 controls. The mean age in both groups was 63. Approximately 41% of participants were women and 91% were British.
The researchers used 2007 — the earliest year of full U.K. Biobank recruitment — as the index PRTR reporting year. In 2007, there were 305 reporting facilities, and co-emission, particularly of heavy metals, was common.
“Using the 2010 PRTR report, heavy metals, other organic pollutants, and other inorganic pollutants retained significant risk associations; chlorinated solvents also met the threshold for significance,” Zhao and colleagues noted.
When modeled as a continuous variable, a greater distance from the nearest polluter was associated with a lower risk of an incident PSP diagnosis for pesticides (OR 0.86), other organic pollutants (OR 0.91), and other inorganic pollutants (OR 0.90, P=0.015 for all), they added.
PSP diagnoses were based on coding and misdiagnosis was possible, the researchers acknowledged. Residual confounding, including participants’ occupation histories, may have influenced results.
Many industrial facilities emitted more than one type of pollutant and data for specific pollutant exposures should be treated as exploratory, Zhao and co-authors added.
