Acrolein (CH2CHCHO) is a potent irritant found in tobacco smoke [in high concentrations up to 50 parts/million (ppm)], wood smoke, and diesel exhaust and is a component of photochemical smog.
Endothelium The endothelium is the thin layer of cells that lines the interior surface of blood vessels,forming an interface between circulating blood in the lumen and the rest of the vessel wall. These cells are called endothelial cells. Endothelial cells line the entire circulatory system, from the heart to the smallest capillary. Endothelial dysfunction, or the loss of proper endothelial function, is a hallmark for vascular diseases, and is often regarded as a key early event in the development of atherosclerosis.