Eighteen-year-olds can no longer legally buy cigarettes in Brookline, as a measure spearheaded by high school students to raise the minimum age to purchase tobacco products kicked in last weekend. The new bylaw will affect 28 local retailers who sell tobacco products, according to Wesley Chin, the town’s tobacco control program coordinator. The 19-plus age requirement was an initiative led by Eric Dumas and fellow members of the Peer Leadership Group at Brookline High School last year in an effort to cut down on smoking by students. Town Meeting approved the idea by an overwhelming vote, 169-1, last spring, and the change took effect as of June 1. The new bylaw puts Brookline with Needham, which was the first community in the state to raise the minimum age to buy tobacco, as well as Arlington, Belmont and Dover as local communities that have enacted a stricter standard than the state, which sets the threshold at 18 years old. “A regulation aimed at increasing the purchase age of tobacco to 19 is good public health policy, as research suggests that those who delay the onset of smoking are less likely to develop a smoking habit,” said Alan Balsam, director of the town’s Health Department, in a statement Monday. Full story for BostonGlobe.com subscribers.