Exposure to Traffic Noise Linked to Higher Dementia Risk

> researchers estimate that as many as 1,216 out of the 8,475 cases of dementia registered in Denmark in 2017 could be attributed to these noise exposures ... Worldwide, the number of people with dementia is expected to exceed 130 million by 2050

Original research article: Residential exposure to transportation noise in Denmark and incidence of dementia: national cohort study (September 2021), https://www.bmj.com/content/374/bmj.n1954

> [Having studied for over ten years almost 2 million people over 60yo in Denmark, including over 100'000 with incident dementia] This nationwide cohort study found transportation noise to be associated with a higher risk of all cause dementia and dementia subtypes, especially Alzheimer’s disease

Besides/before the cognitive damages in focus,

> Transportation noise is considered the second worst environmental risk factor for public health in Europe, only surpassed by air pollution. ... Epidemiological studies have consistently linked transportation noise to various diseases and health conditions, such as coronary heart disease, obesity, and diabetes. The proposed biological mechanisms for an effect of noise on health are noise induced stress reactions, with activation of the autonomic nervous and the endocrine system and subsequent release of stress hormones, affecting several physiological functions. Exposure to noise during the night can also lead to sleep disturbance and fragmented sleep. Experimental studies have found associations between transportation noise at night time and endothelial dysfunction, increased oxidative stress, alterations in the immune system, and increased systemic inflammation, which in turn are regarded as early events in the onset of dementia and Alzheimer’s disease