Air pollution amplifies Parkinson’s risk when genetics also a factor
Study notes need to lower exposure to fossil fuels, smoke, and the like
Air pollution may increase the risk of Parkinson’s disease, particularly in people who are already genetically predisposed to develop the disorder, a study shows.
“We discovered that individuals with elevated genetic susceptibility and heightened exposure to air pollutants faced a markedly heightened risk of [Parkinson’s],” its researchers wrote. “Therefore, applying effective techniques for mitigating air pollution as soon as possible is crucial in order to protect individuals, particularly those having a high genetic sensitivity, from a higher risk of [Parkinson’s] development.”
The study, “Genetic susceptibility modifies the association of long-term air pollution exposure on Parkinson’s disease,” was published in npj Parkinson’s Disease.
Genetics can be a Parkinson’s risk factor, tied to between 5% and 10% of cases
The causes of Parkinson’s remain poorly understood, but it’s well established that a person’s genetics play a substantial role in influencing disease risk.
Several studies also suggest that exposure to air pollution can increase the risk of Parkinson’s. But whether the effects of air pollution on Parkinson’s risk are mediated by genetics is less clear.
Scientists in China conducted an analysis of data from the U.K. Biobank covering roughly 312,000 people who were followed for a median of more than 12 years. Over the course of follow-up, 2,356 (0.76%) of these individuals developed Parkinson’s.
The scientists calculated a Parkinson’s risk score for each individual based on genetic data, and they also collected information about their exposure to air pollution. Statistical models then were used to estimate the effects of pollution and genetics on Parkinson’s risk.
Results showed that two types of air pollutants were associated with an increased Parkinson’s risk: PM10 (particles found in smoke and dust that are less than 0.01 mm in diameter), and nitrogen dioxide (NO2, generated by motor vehicles, fossil fuels and their industries, etc.). People in the highest quartile of PM10 exposure were at 20.1% increased risk of Parkinson’s, and those in the highest quartile of NO2 exposure were at 24.7% greater risk.
‘Considerable amplification’ of risk when genetics and pollutants involved
The effects of these pollutants were much stronger, however, when genetics also were considered. Individuals in the highest quartile of PM10 or NO2 exposure and at highest genetic risk of Parkinson’s had more than twice as high a disease risk than did people without genetic risk with less pollution exposure.
“Upon evaluating the compounded effects of genetic predisposition and air pollutant exposure, we detected a considerable amplification in the risk of [Parkinson’s] among participants possessing heightened genetic susceptibility and concurrently exposed to elevated air pollutant concentrations,” the scientists wrote.
Study findings indicate that people whose genetics put them at increased risk of Parkinson’s may be more vulnerable to air pollution, the scientists said.
“Therefore, our findings imply that reducing air pollution levels would provide a potential benefit for individuals who are genetically predisposed” to Parkinson’s, they added.