If Americans would switch to bikes from their cars for half of the short trips they make during the warmer six months, national health costs could be cut by up to $3.8 billion each year, according to a study published in Environmental Health Perspectives, the journal of the National Institute of Environmental Health Sciences.

The study, conducted by researchers at the University of Wisconsin-Madison, focused on identifying air pollution reductions in the 11 largest metropolitan areas in the upper Midwest if short auto trips were eliminated.

The researchers estimated the reductions in emissions of very fine particles, which lodge in the lung, could reduce by 433 annual deaths from cardiovascular and pulmonary diseases.