A new study has discovered that exposure to air pollution significantly affects our memory, causing a memory loss equivalent to up to ten years of aging.
The study, conducted by researchers from the University of Warwick, examined how air pollution affected people's memory. It involved analysis of a nationally-representative sample of 34,000 individuals across 318 geographical areas in England.
The researchers examined data on air quality for each district, including levels of both nitrogen dioxide (NO2) and particulate matter (PM10), which has a diameter of 10 micrometers or smaller. Both nitrogen oxide and particulate matter can come from burning fossil fuels from car and other vehicle exhausts, power plants and industrial emissions.
The study also involved asking participants to remember 10 words in a standardized word-recall test and were scored from zero to ten based on their responses. Participants' age, health, level of education, ethnicity, and family and employment status were also considered as they are factors that can impact memory.
Results revealed that participants living parts of England with high levels of NO2 and PM10 had significantly worse memory scores. According to the researchers, the gap between the memory scores of people from England's cleanest areas, found on the west coastline in districts such as Devon and West Somerset, and those from the most-polluted areas, places like Kensington and Islington in London, is equivalent to memory loss from 10 extra years of aging.
Co-author 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."
Meanwhile, co-author Professor Nattavudh Powdthavee pointed out: "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."
