Air pollution and hardening of arteries — Long term exposure to air pollution may be linked to heart attacks and strokes by speeding up atherosclerosis – Long term exposure to air pollution may be linked to heart attacks and strokes by speeding up atherosclerosis, or “hardening of the arteries”. The researchers found that higher concentrations of fine particulate air pollution (PM2.5) were linked to a faster thickening of the inner two layers of the common carotid artery, an important blood vessel that provides blood to the head, neck, and brain.