WEST SPRINGFIELD -- The Joint Committee on Marijuana Policy held its second public hearing on Monday, listening to testimony from several Western Massachusetts mayors, a prominent addiction specialist and citizens concerned about how Beacon Hill will handle the legalization of marijuana.

The committee is tasked with considering dozens of bills that would alter the state law passed by voters in November. Monday's hearing at West Springfield High School was a chance for the 17 state House and Senate members to hear ideas from the general public.

Several members hail from the Pioneer Valley, including Rep. John Velis, D-Westfield, and Sen. James Welch and Rep. Michael Finn, both Democrats from West Springfield. The committee is led by Rep. Mark Cusack, D-Braintree, and Sen. Patricia Jehlen, D-Somerville.

West Springfield Mayor Will Reichelt said a majority of the town's voters opposed the ballot initiative, called Question 4, and there is concern that the Town Council cannot stop retail pot shops from opening. The law requires a ballot initiative in each town that wants to opt out.

"I'm not aware of any other zoning that has to go on the ballot to opt out," said Reichelt. "If (retail) is allowed in the community, make sure we have the ability to zone it in a way that's good for our community."

As written, the law allows the state to overrule a local retail marijuana zoning ordinance, a dynamic Reichelt said was not fair. He added that the current tax structure does not provide enough revenue to municipalities.

Right now, a town or city cannot impose a tax higher than 2 percent, while the state can add another 3.75 percent.

"If a community wants ... to increase it, I think that should be in our hands," said Reichelt.

Mayor Alex Morse of Holyoke was a vocal supporter of Question 4. He told the committee that retail marijuana will put a big dent in street sales, but only if taxes are kept low.

"If we raise it too high too soon, it won't have the intended consequence of driving out the black market," Morse said. "If you want to raise the tax at all, just raise the portion that would go directly to the local communities (instead of) an increase in the overall tax."

Morse disagreed with Reichelt about local control of the industry, saying town officials should not have the authority to ban pot shops, framing the issue as a matter of personal choice.

In November's election, 54 percent of Massachusetts voters approved the ballot measure that allows adults to possess, use, grow and gift marijuana, with some restrictions. Gov. Charlie Baker signed a bill, passed by just a few legislators in late December, delaying the opening of retail pot shops until July 2018.

"Please don't hold up or delay the process any longer," said Morse to a round of applause from several dozen people in attendance.

Local officials from Amherst said some of the language in the law is too vague and the committee should clarify certain sections, while residents of Easthampton and other towns said the law should be left alone entirely, considering it was passed by popular vote.

The committee heard detailed testimony from Dr. Ruth Potee, a Greenfield physician and addiction specialist who speaks at local schools about the dangers drugs pose to young people's brains. She said the minimum age to legally purchase marijuana should be 25, the age at which the brain is done developing.

She said people under 25 tend to believe that marijuana is not addictive or harmful, that it alleviates anxiety and insomnia, and is preferable to alcohol and tobacco. There is a vast "chasm of belief" between those ideas and "what we think as scientists," said Potee.

"I actually think alcohol and marijuana are similar substances in the fully adult brain, and I think they need to be regulated in a similar fashion," said Potee.

She called for the committee to limit the psychoactive chemical THC in retail marijuana to 15 percent at most. Some marijuana edibles and concentrates are 90 percent THC.

"How high do you need to get? Honestly," said Potee.

Echoing a representative of the anti-drug West Springfield CARE Coalition, Potee encouraged the committee to ban sugary treats that look like candy, which she argued are specifically designed to entice teenagers.

In written testimony, Springfield Mayor Domenic Sarno pointed out several "ambiguous" areas of the law and drew the committee's attention to the case of Mary Jane Makes Your Heart Sing, a short-lived business that charged a $20 cover and gave customers "free" marijuana.

Sarno said it will be difficult to allocate "scarce resources to monitor and enforce future attempts to circumvent the law." At this point, it remains impossible to tell if a 2 percent local tax would be enough to cover such costs, he said.

The committee is accepting written testimony from the general public. Two public hearings are scheduled for next month. The first is at 11 a.m. on April 3 at the Statehouse in Boston. The second is April 10 at 4 p.m. at Shrewsbury High School.