Even temporary rises in air pollution may impair memory and thinking in older men, according to new research.
Scientists working on the study, which tracked nearly 1,000 men living in the Greater Boston area, said the research was important in two particular ways. First, the findings indicate a potential causal link from pollution to brain function, expanding existing scholarship that ties bad air to heart and lung issues. Second, the study suggests that even relatively low levels of air pollution can negatively impact cognitive function, and over short periods of time.
There is some encouraging news. The impact from short-term exposure can be reversed by a change in living conditions, though the discovery of brain impact remains concerning, said Andrea Baccarelli, a senior author on the study published in the journal Nature Aging and professor of environmental health sciences at Columbia University.
“These shorter-term effects are reversible: when air pollution clears, our brain reboots and starts working back to its original level,” Baccarelli said. “However, multiple occurrences of these higher exposures cause permanent damage.”
The study compiled multiple cognitive test scores, including word and number recall and verbal fluency, and checked the scores against local pollution levels of PM2.5s, which are airborne particles smaller than 2.5 micrometers. The men involved in the study were white and had an average age of 69.
The effect was evident even when concentrations of PM2.5s stayed below 10 micrograms per cubic meter, the World Health Organization guideline level. That level, by the way, is routinely surpassed in major cities. London, for example, the Guardian reports, uses 25 micrograms per cubic meter as its “safety” threshold.
In an interesting development, the new brain-focused study found evidence that test scores were less affected by short-term rises in air pollution if the male participants were taking aspirin or other non-steroidal anti-inflammatory drugs, known as NSAIDs.
“Our study indicates that short-term air pollution exposure may be related to short-term alterations in cognitive function and that NSAIDs may modify this relationship,” the authors wrote, but stopped short of recommending this anti-inflammatory drug regimen strictly as a “treatment” against pollution impacts.
A separate study led by Jamie Pearce at Edinburgh University has found that exposure to air pollution in childhood was linked to poorer thinking skills late in life.
Late last year, a 9-year-old London girl who died after an asthma attack is thought to be the first person in the world to have air pollution listed as an official cause of death.
Pollution studies have long highlighted the effects on human lives of long exposure to dirty air. And in the developed world the harm is more common in poorer neighborhoods than wealthier. That inequity has pushed many environmentalists to insist to U.S. President Joe Biden and other leaders that “environmental justice” feature in climate-change plans.