Exposure to air pollution affects performance on hippocampus-dependent cognitive tasks

Abstract

The effects of exposure to air pollution on cardiovascular and pulmonary health are well explored in current literature. However, an understanding of how such pollutants may affect cognitive function is yet to be reached. This paper first reviews the available literature assessing the link between both acute and chronic exposure to air pollution – specifically to particulate matter (PM) and nitrogen dioxide (NO2) – and cognitive function. The results from this review suggest that investigation of the effects of AP on hippocampus-based functions, including spatial navigation and memory, would also be beneficial This paper then describes the methodology employed in a pilot study to address the link between lifetime exposure to PM2.5 and NO2 and performance on hippocampus-dependent tasks. 46 participants (12 males; 20.73 [SD = 3.68]), recruited at the University of Birmingham, completed 3 cognitive tasks: a hippocampus-dependent spatial working memory task (MemoryArena), a hippocampus-dependent transfer learning task (TL) and a hippocampus-independent attention network task (ANT). Lifetime Exposure to PM2.5 was significantly positively correlated with the number of training trials required to reach 80% accuracy on the MemoryArena task; participants who had been exposed to higher levels of PM2.5 throughout their lifetime required more (XX trials/ppb PM2.5 exposure) training trials to learn the correct configuration of items. Performance on the Phase 1 of the TL task – which corresponds to acquiring knowledge of the initial associations between items – was correlated with lifetime exposure to PM2.5 (r = .392*, p = .010), lifetime exposure to NOx (r = .372*, p = .015) and exposure to NOx in the last 3 years (r = .359*, p = .020). In the ANT, exposure to PM2.5 and NO2 was also linked with increased reaction time (secs) on Congruent Valid trials (r = .552**, p = .000b; and r = .500**, p = .002 respectively). Exposure to PM2.5 since moving to Birmingham was significantly associated with Reaction Time (secs) on Incongruent Valid trials (r = .337*, p = .045) and Incongruent Invalid trials (r = .340*, p = .043). Implications of these finding and proposed future directions are discussed

    Similar works