According to a recently published study, exposure to road and traffic noise over a longer period of timeassociated with a higher risk of dementia. The study results show that the development of dementia in such cases would be possible, especially in Alzheimer's disease. The researchers estimate that a large proportion of dementia cases can be attributed to this noise exposure. Furthermore, this finding suggests great potential for prevention by reducing traffic noise.
How traffic noise can affect the brain
In addition to common risk factors such as cardiovascular disease and unhealthy lifestyles, environmental pollution can also play a role in the development of dementia. Traffic noise is also considered the second worst environmental factor for public health in Europe after air pollution. Statistics show that around a fifth of the European population is exposed to such risk above the recommended level of 55 dB (decibels). Studies have consistently linked such noise pollution to various diseases and health conditions such as coronary heart disease, obesity and diabetes. However, there is little research into traffic noise and dementia and the results are contradictory. Therefore, the researchers examined the association between long-term residential exposure to road traffic and railway noise and the risk of dementia in two million adults over 60 years of age. They estimated noise on the most and least exposed sides (or facades) of all residential addresses in Denmark.
Taking into account potential influencing factors related to residents and their neighborhood, the researchers found that 10-year average exposure to road traffic and railway noise on the most and least exposed building sides is associated with a higher risk of overall dementia. These associations showed a general pattern of increased risk at higher noise exposure levels, but with a flattening or even small reduction in risk at higher noise levels. Possible explanations for the influence of noise on health are:Release of stress hormonesand sleep disorders. These could lead to a type of coronary heart disease as well as changes in the immune system and inflammation. The resultsthis studycould have a major impact on estimating the burden of disease and health care costs from traffic noise.
