The public health risks posed by automotive particulate emissions are well known. Such particles are sufficiently small to reach the deepest regions of the lungs; and moreover act as carriers for many potentially toxic substances. Historically, diesel engines have been singled out in this regard, but recent research shows the need to consider particulate emissions from gasoline engines as well. Already implicated in more than one respiratory disease, the strongest evidence in recent times points to particle-mediated cardiovascular disorders (strokes and heart attacks). Accordingly,...