Ronna Schaffer of Attleboro was an early education teacher for more than two decades. She worked with children of all ages, including infants and toddlers. She loved the children, but had one concern from what happened after many were dropped at day care each morning.

“I would smell smoke in their clothes and in their hair and car seats,” Schaffer said. “I started to think, ’Wow, if it’s so pervasive that I smell this, what’s happening inside?’”

Years later, as a retiree, Schaffer lobbied her then-state representative, Paul Heroux, to push for a bill called “Little Lungs.” The bill was designed to prevent adults from smoking in a car with children small enough to fit into car seats. Police would be allowed to stop the driver and issue a citation. Heroux sponsored the bill three times as a state representative from 2013 to 2017. It never passed.

The idea got new life when Heroux was elected as mayor of Attleboro, taking office in January 2018. Heroux has now proposed the “Little Lungs” ordinance on a city level.

“If a police officer observes that somebody has a cigarette in hand and there is a child in a car seat, that gives them the grounds to pull somebody over and issue a citation based on that,” Heroux told WGBH News.

Right now, the proposed fine is $100. Attleboro city councilors, who have yet to consider the ordinance, could vote to change the amount of the fine. Second-hand smoke is a public health danger, to adults and children, according to the American Lung Association. Heroux says confined spaces, like a car, only make the health effects worse.

“It’s in the child’s best interest not to smoke around them, especially in a car,” Heroux said.

There is some criticism of the proposed ordinance on civil liberties grounds. Rahsaan Hall, director of the Racial Justice Program for the ACLU of Massachusetts, said the ordinance could lead to racial profiling.

“For as much as we appreciate the desire to want to get to a serious health concern, which is second-hand smoke for children,” Hall told WGBH News, “it’s always a concern for the ACLU whenever we are creating more opportunities for people to be engaged with police.”

Hall said that concern is greater for drivers of color.

“We full well know that there are racial disparities in the way that people in communities of color, particularly black and Latinx folks, are stopped by the police,” Hall said. “There are more adverse outcomes from those stops.”

Heroux says he cannot let what might happen stop him from pushing to address a public health issue.

“If somebody were to do that, we’ll deal with that problem of a racially-profiling police officer,” Heroux said. “Just because somebody might be doing the wrong thing over here, it doesn’t mean that we don’t do the right thing over here.”

Maine, New York, New Jersey and Hawaii have similar ordinances in certain areas of those states. According to the Massachusetts Department of Public Health, no city or town in the state has such an ordinance.

Heroux hopes the city council will vote to make Attleboro the first in the state to have one. At the time of this article's publication, the ordinance does not appear on any agenda for upcoming city council meetings.

A previous version of this story incorrectly stated the mayor of Attleboro's first name. The change has been reflected above. We regret the error.