Air pollution impairs mental health

Exposure to relatively high levels of air pollution is associated with increased use of community mental health services by people with dementia, shows a large long-term study focusing on a high traffic area of ​​London, UK, published in an open access journal. Mental Health ⁽¹⁾.

The researchers suggest that the decrease in nitrogen dioxide and particles can reduce demand in urban areas and help free up resources in several overburdened psychiatric services.

Much research has focused on the effects of air pollution in older age, including its possible role in accelerating cognitive decline and dementia.

They add that many studies have focused on the effects of air pollution in older age, including its possible role in accelerating cognitive decline and dementia.

But while air pollution has been linked to greater use of healthcare services by people with dementia, these studies have focused primarily on hospital services rather than hospitals. public utilitieswhere the majority of people with this condition are cared for in the UK.

For nine years 5024 elderly people

To fill this gap, the researchers studied nine years of 5,024 older people (aged 65 and over) in four south London boroughs seeking community-based mental health services. initial diagnosis of dementia in the period from 2008 to 2012.

More than half (54%, 2718) were diagnosed with Alzheimer’s diseasecaused by deposits of plaques and tangles in the brain; one fifth (20%, 1022) had vascular dementiacaused by damage to the vessels of the brain; and more than a quarter (26.5%, 1330) had another type of dementia or unspecified dementia.

Quarterly estimates of two major air pollutants, nitrogen dioxide, have been published (NO2) And suspended particles (PM2.5 and PM10)— in the area surrounding the participants’ homes, they interacted with their anonymous mental health stories in the period 2008-12

Exposure to all air pollutants was higher in people with vascular dementia.

Exposure to all air pollutants was higher in people with vascular dementia and lower in people with Alzheimer’s disease. The follow-up period was divided into three periods: up to 12 months, up to 5 years and up to 9 years after diagnosis.

In that first year of observationhigher exposure to all air pollutants was associated with increased use of community mental health services by people with dementia after controlling for potential contributory factors.

The higher the level of exposure, the more often these services are used, especially in the case of NO2 exposure. It was especially noticeable in people with vascular dementia.

Compared to those who lived in areas with the lowest NO2 exposure, those who lived in areas with the highest NO2 exposure 27% more likely to use these services. And for those exposed to the highest levels of very fine particles (PM2.5), 33% more likely to seek mental health services.

The association between PM2.5 and more frequent mental health service visits was still clear after 5 and 9 years for people with Alzheimer’s disease and vascular dementia, but was more clear for people with vascular dementia.

During the study period, Mini Mental State Exam (MMSE) measure brain function and Health of the Nation Outcome Scale (HoNOS65+) For measure physical health and social activity.

NO2 exposure has been associated with higher HoNOS65+

At all time points, NO2 exposure was associated with higher HoNOS65+, which indicates deterioration in health and social functioning, including the ability to perform routine activities of daily life, but not deterioration in cognitive functions. Similar results were obtained for particles.

air pollution this was not related to brain function as measured by MMSE scores during the study period. However, NO2 exposure was associated with higher HoNOS65+ scores at all time points, indicating poorer health and social functioning, including the ability to perform daily activities. The results were similar for PM2.5.

This is an observational study, so definitive conclusions about causation cannot be made. The researchers also acknowledge that they were unable to assess the effects of exposure to pollutants at an early age, fluctuations in exposure over 9 years, or changes in exposure due to mobility of residence or time spent away from home.

However, based on their findings, they calculated that if the annual PM2.5 exposure in London (11.6 µg/m3 in 2019) were reduced to 5 µg/m3, as recommended World Health OrganizationThe number of times people with dementia visit community mental health services could fall by 13% per year.

Similarly, lowering annual NO2 levels (39 µg/m3 in 2019) to the recommended limit of 10 µg/m3 could reduce annual mental health visits by 38%. These ratings can extends to other major cities from high-income countries with heavy diesel traffic, they suggest.

“Reducing exposure to pollutants can reduce the use of mental health services for people with dementia, freeing up the resources of already overburdened mental health services.”

“Based on the evidence presented, we argue that air pollution can be considered an important population-level target for reducing the use of mental health services in people with dementia, especially people with vascular dementia,” they write.

They add: “Reducing air pollution, and NO2 in particular, through public health interventions, such as expanding ultra-low emission zones, has the potential to improve the functioning and disease trajectories of people with dementia.”

“Reducing exposure to pollutants can reduce the use of mental health services for people with dementia, freeing up the resources of already overburdened mental health services,” he concludes.