Research has revealed a significant link between long-term exposure to road traffic noise and an increased risk of developing Parkinson's disease. The largest study of its kind, published in JAMA Neurology, followed 3.1 million Danish individuals aged 40 and over for 18 years, using nationwide health register data to establish this association.
Parkinson's disease is a progressive neurological disorder that causes damage to parts of the brain over time, leading to movement and balance problems. While previous research has highlighted environmental toxins like air pollution, microplastics, and pesticides as risk factors for neurological disorders, this study specifically examines the connection between noise pollution and Parkinson's disease risk.
The study found a consistent association: for every 11.5dB increase in noise levels at the most exposed exterior of a participant's residence, their risk of developing Parkinson's disease rose by 3% over the study period. Researchers suggested that having a quiet area within the home could help mitigate this increased risk. Thomas Münzel, one of the study's authors, noted that environmental noise is "still a young entrant in the Parkinson's disease risk-factor literature," advocating for further research into this newly identified credible risk factor.
While the study accounted for air pollution, it lacked information on individual lifestyle factors. However, the researchers argue that the consistent association observed across different education and income levels suggests lifestyle factors would not have significantly altered the findings. Potential biological pathways linking noise exposure to Parkinson's disease involve stress responses and disrupted sleep, with chronically disturbed sleep from noise pollution potentially leading to increased cortisol levels.
Environmental epidemiologists, including Professor Anna Hansell of the University of Leicester, noted that noise is likely a general stressor rather than a specific environmental risk factor for Parkinson's. Dr Peter Chan highlighted the interesting aspect of varying noise levels within a home, while John Stewart, chair of the UK Noise Association, suggested this research adds to evidence linking traffic noise to health and recommends governments focus on reducing main road noise.