Water pollution linked to higher risk of rare brain disorder

A study of more than 500,000 people found that living near water-polluting facilities may cause a rare brain disorder called progressive supranuclear palsy.(CN) — Those who live near facilities that release water pollutants may face a higher risk of developing a rare brain disorder that mimics Parkinson’s disease but progresses much faster, scientists say.The study, published Wednesday in Neurology, found an association between living near these facilities and developing progressive supranuclear palsy, or PSP. However, it does not prove that pollution causes the disorder.PSP belongs to a group of neurodegenerative diseases known as atypical parkinsonism. It shares some symptoms with Parkinson’s disease but usually progresses much faster and responds differently to treatment.“These results suggest that environmental water pollutants potentially play a role in the development of progressive supranuclear palsy,” said study author Charlie Weige Zhao, a physician at Harvard Medical School in Boston.The researchers followed more than 500,000 people in the United Kingdom for up to 25 years. During that time, 221 developed PSP. They matched each person with PSP to 10 people of the same age and sex who did not have the disorder.Using participants’ home addresses in 2007, the researchers estimated how close they lived to industrial facilities that reported releasing pollutants. Facilities included wastewater treatment plants, intensive aquaculture operations, chemical plants and thermal power stations.About one-third of people who developed PSP lived within roughly three miles of one of these facilities, compared with about one-quarter of those who did not develop the disorder.The differences also varied by pollutant type. Roughly 16% of people with PSP lived near a facility that released pesticides, compared with 11% of those without the disorder.After accounting for factors such as age, sex and education level, the researchers found that people living near facilities that released pesticides such as atrazine, simazine and diuron were 66% more likely to develop PSP than those who did not live near such facilities.People living near facilities that released inorganic pollutants, including phosphorus, nitrogen and fluorides, were 60% more likely to develop the disorder. For organic pollutants such as benzene, ethylbenzene and toluene, the likelihood was 52% higher. For heavy metals such as lead, mercury and cadmium, it was 38% higher.The team found no association between PSP and proximity to facilities that released chlorinated solvents or persistent organic pollutants.“We also found some evidence that the risk of PSP decreased in proportion to how far away people lived from the facility as the distance increased to up to about six miles,” Zhao said. “There is also evidence that the length of time people lived near the polluting facilities played a role in their risk of PSP.”Researchers did not have complete information about participants’ work histories, preventing them from analyzing potential exposure to pollutants in the workplace. Many facilities also released multiple types of pollutants, making it difficult to isolate the effects of any one type.Zhao emphasized that the overall risk of developing PSP remains low, regardless of where people live.“Further studies are needed to confirm these findings, but this is a step forward in understanding what raises a person’s chance of getting PSP,” he said.Subscribe to our free newslettersOur weekly newsletter Closing Arguments offers the latest about ongoing trials, major litigation and rulings in courthouses around the U.S. and the world, while the monthly Under the Lights dishes the legal dirt from Hollywood, sports, Big Tech and the arts.Additional Reads