"In a study published in the New England Journal of Medicine, they found while heart attacks are reduced for one day in the fall following the clocks’ return to standard time, heart attacks increased for three days in the spring following the start of daylight saving time."
"...workplace injuries increase the Monday after the clocks spring forward because of workers’ sleep loss, but there is no compensatory benefit in the autumn when clocks fall back. Estimates of potential lives saved from driver and pedestrian fatalities with later sunsets range from 180 people per year to 366—the equivalent of saving a life every day."
http://www.bostonglobe.com/ideas/2014/10/04/why-massachusetts-should-def...