Is there a link between air pollution and damage to memory?

New research from the University of Warwick found that human memory is significantly worse in parts of England with high levels of air pollution.

The research used Understanding Society data to look at the difference in memory quality between England’s cleanest and most polluted areas.

The researchers found that living in the most polluted areas of England caused damage to the memory, equivalent to the loss of memory from 10 extra years of ageing. This is consistent with previous smaller-scale laboratory research on rats and other animals. But this research, by Nattavudh Powdthavee, Professor of Behavioural Science, and Andrew Oswald, Professor of Economics and Behavioural Science, is some of the first to confirm the same in humans.

The researchers examined 34,000 adults randomly sampled from across England’s local-authority districts. Everyone in the study was asked to remember 10 words in a standardized 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.

Memory slowly worsens as people grow older. The researchers estimate that the difference in memory quality between England’s cleanest and most-polluted areas is equivalent to the loss of memory from 10 extra years of ageing. 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.

“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”, said Professor Powdthavee, “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.”

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”.

You can read the full research paper here

This research featured in the media:

The Times, Air pollution takes decade off memory, study suggests 
Daily Mail, Breathing polluted air could damage the memory and age the brain by 10 YEARS in the worst affected areas, study warns