The Montgomery County Housing Authority has become the latest public housing agency to ban smoking.

Starting July 1, the ban affects its 616 units countywide, executive director Joel Johnson said at a county commissioners meeting Thursday. The policy prohibits smoking indoors but will allow residents to smoke outside at least 25 feet away from buildings.

It mirrors bans in Philadelphia and Chester County, and a broader effort in public housing nationwide. In November, the U.S. Department of Housing and Urban Development said it would require all federally subsidized housing authorities to implement nonsmoking policies in the next several years.

Johnson outlined the policy during a meeting at which the commissioners passed an ordinance banning smoking at county parks, trails, and historic sites. Commissioners said each move was a step to promote health and protect residents from secondhand smoke.

Johnson said the housing authority had received enormous numbers of complaints about smoke spreading through hallways and into ventilation systems. About 30 percent of its residents are smokers, he said. The agency's board adopted the policy in March and is offering free smoking cessation classes to residents.

Commissioner Valerie Arkoosh said she spoke with the housing authority about a potential ban last year. Residents "were pleading with me, actually, to try to make their building smoke-free," she said.

Shirley O'Donnell, president of the residents council at Marshall W. Lee Towers in Conshohocken, said she can smell smoke as soon as she enters the elevator in her building. She said it was difficult for a nonsmoker to live in an apartment between two people who smoke in their units.

"I feel sorry for the smokers, I know it's going to be hard for them," she said.

The ban on smoking in county parks also prohibits e-cigarettes from all parks and trails. Officials say the ordinance will promote health and reduce litter. Arkoosh said that ordinance, which takes effect immediately, was consistent with the purpose of county parks: to encourage residents "to get outside and be healthy."