Breathing polluted air could damage the memory and age the brain by 10 YEARS in the worst affected areas, study warns
- High levels of nitrogen dioxide (NO2) and particulates (PM10) affected memory
- The most-polluted air was found in Kensington and Islington in London
- A 50 year old in polluted Chelsea has the memory of a 60 year old in Plymouth
People living in polluted parts of England can expect to be more forgetful as scientists draw a link between high levels of pollutants and memory loss.
Researchers from the University of Warwick found that human memory is significantly worse in areas with high levels of nitrogen dioxide (NO2) and air particulates (PM10).
Comparing the memory of those living in England’s most-polluted areas with those in the cleanest air found that those breathing in more pollutants had the memory loss equivalent to someone 10 years older than them in the clean area.
The same result had been found in a prior smaller-scale laboratory research on rats and other animals.
London’s polluted skyline at sunset (stock). The researchers examined 34,000 English citizens randomly sampled from across England’s local-authority districts
But the new research, by professors Nattavudh Powdthavee and Andrew Oswald, is some of the first to confirm the same in humans.
The researchers examined 34,000 English citizens randomly sampled from across England’s local-authority districts.
Everyone in the study was asked to remember 10 words in a standardised word-recall test.
The analysis adjusted for a large number of other influences on the quality of people’s memory — including people’s age, health, level of education, ethnicity, and family and employment status.
The report, revealed a strong link between air pollution and impaired memory, and is to be published in the journal Ecological Economics.
Although memory slowly worsens as most people grow older the authors estimate that those in those living in England’s most-polluted have the equivalent of 10 extra years of ageing on their clean air inhabiting counterparts.
Professor Andrew Oswald said: ‘When it comes to remembering a string of words, a 50 year old in polluted Chelsea performs like a 60 year old in Plymouth.
‘We are still not exactly sure how nitrogen dioxide and air particulates act to do this’.
The traditional British seaside resort of Weston super mare in Somerset (stock)
The most polluted air in England is in places like Kensington and Islington.
The cleanest is on the west coastline in districts like Devon and West Somerset.
Professor Powdthavee said: ‘There is a little prior evidence of a negative association between levels of traffic pollution and memory using data on elderly individuals and in children.
‘But almost all research in human studies on this topic has been based on elementary correlations and not on nationally representative samples of individuals in a country. We have tried to solve these two problems in our study.’
Using a nationally representative sample the researchers have been able to study the link between data on a standardised word-recall test that was done in the year 2011 by 34,000 randomly sampled English citizens.
They then collated this with data on NO2 and PM10 across 318 geographical areas.
The paper does not focus on the extreme loss of memory that is a characteristic of dementia-like conditions.