SEATTLE — Even brief exposure to highway pollution could cause significant increases in blood pressure, a new study from the University of Washington has found, adding to a growing body of work correlating vehicle exhaust with negative health outcomes. The effects are near immediate: Two hours in Seattle’s rush hour was enough to increase blood pressure by nearly 5 millimeters of mercury, a jump that would push someone with normal levels to elevated or from elevated levels to stage 1 hypertension. The peer-reviewed study, published in the Annals of Internal Medicine, was conducted by a team at...