With Massachusetts voters being asked in November to decide whether to legalize medical marijuana, the Dukes County Youth Task Force has come out against the proposal, saying it would exacerbate existing marijuana use by Island teens.

“The Youth Task Force feels committed to opposing ballot question three, primarily based on the fact we don’t want there be more access for kids for marijuana,” task force coordinator Theresa Manning told the Gazette.

Ballot question three asks voters to approve a law that would eliminate state criminal and civic penalties for the medical use of marijuana for qualifying patients. In brief, the patients must have a “debilitating medical condition,” including cancer, glaucoma, hepatitis C and multiple sclerosis, and obtain a written certification from a physician.

Ms. Manning said that on the Island, teens use marijuana at a rate much higher than the state and national average, and teens already face pressure from a tourist and party culture.

“We’ve seen an increase in marijuana use since decriminalization,” she added, referring to a 2008 vote that decriminalized possession of marijuana under one ounce. She said that the proposed new law would eliminate the stigma associated with the drug and suggest that there are medical or health benefits.

But she said that marijuana “really does impair” a developing brain, including memory, cognitive function and IQ.

“Ballot Question 3 to legalize marijuana as medicine would increase both access to marijuana, and social acceptability of the drug — and the research clearly shows that these two variables have direct causal link to increased teen marijuana use,” the task force said in a statement. “The risks of medical marijuana laws outweigh the benefits. Therefore, the Dukes County Health Council Youth Task Force Coalition opposes Ballot Question 3.”