NEW DELHI: People living in regions with median levels of air pollution have a 56 per cent greater risk of developing Parkinson's disease compared to those living in regions with the lowest level of air pollution, finds a study.

The study, published online in the journal Neurology, was conducted to identify national, geographic patterns of Parkinson's disease and test for nationwide and region-specific associations with fine particulate matter.

The population-based geographic study identified nearly 90,000 people with Parkinson’s disease from a Medicare dataset of nearly 22-million.

"Previous studies have shown fine particulate matter to cause inflammation in the brain, a known mechanism by which Parkinson’s disease could develop," said Brittany Krzyzanowski, a researcher at Barrow Neurological Institute in the US, who led the study.

"Using state-of-the-art geospatial analytical techniques, we were, for the first time, able to confirm a strong nationwide association between Parkinson’s disease and fine particulate matter in the US," she added.

The study also found that the relationship between air pollution and Parkinson’s disease is not the same in every part of the country, and varies in strength by region.

"Regional differences in Parkinson’s disease might reflect regional differences in the composition of the particulate matter. Some areas may have particulate matter containing more toxic components compared to other areas," Krzyzanowski said.

Researchers hope the data from this novel study will help enforce stricter policies that will lower air pollution levels and decrease the risk for Parkinson's disease and other associated illnesses.

"Despite years of research trying to identify the environmental risk factors of Parkinson’s disease, most efforts have focused on exposure to pesticides," Krzyzanowski said. "This study suggests that we should also be looking at air pollution as a contributor in the development of Parkinson’s disease."