As marijuana smoke wafts around Long Island, here's what to know about health effects and where it's legal

Since New York legalized the recreational use of marijuana in 2021, the pungent smell of weed wafting through the air has become more noticeable for many Long Islanders as they walk down the street, pass windows of houses and apartments, or sit in the park.

Even though no state-licensed recreational cannabis dispensary has yet opened on Long Island, and few have opened elsewhere in the state, Long Islanders are able to obtain marijuana legally through home deliveries. And stores illegally selling marijuana in New York have flourished, with an estimated 1,400 in New York City alone as of last winter, according to officials there.

Yet is the marijuana sold illegally safe? Are there negative health effects to secondhand smoke? Could you get high passing through a cloud on the street? Where can someone legally light up?

Here are answers to those and other questions Long Islanders may have as marijuana use becomes more open in public.

How dangerous is secondhand marijuana smoke?

It depends on how much you're exposed to and where. A study released last year that measured air quality in a room in which several people were smoking marijuana out of a bong — a type of water pipe — found very high levels of fine particulate matter, which can damage the lungs. Levels remained elevated hours after the smoking ended.

“Even if you’re not smoking, you’re going to get a really large dose of fine particles, not only during the time the smoking is happening,” said Katharine Hammond, a professor of public health at the University of California, Berkeley, and a study co-author.

R. Lorraine Collins, a public health professor at the University at Buffalo, said she is especially concerned about children living in homes where adults regularly smoke inside. “Their lungs are very vulnerable,” she said.

Hammond said that if you live in an apartment and your neighbor is smoking, you also can be exposed to fine particulate matter.

How about if I’m outside?

“The outdoor situation is a whole lot healthier and safer, because the vape, or the particulate matter [from smoke], is being dissipated in the air,” Collins said.

Passing someone on the sidewalk who is smoking is "not really high risk,” she said. Sitting for a few minutes next to someone on a park bench while they’re smoking could present slightly more risk, she said.

One of Collins’ chief concerns of people smoking marijuana in public is, “Does a kid look at that as modeling a behavior they may want to try?”

Can I get high from secondhand smoke?

Not if you’re just passing someone on the street, Collins said.

With most exposure to secondhand smoke, “You can find detectable levels of THC, but typically it's not at the level to change behavior," she said. THC is the chemical in marijuana that causes a high.

If you're in a crowded indoor space — such as a concert hall — for a long period of time and you're near multiple people who are smoking, you may "start feeling somewhat of an effect," but it's unlikely to be a significant high, she said.

What are the overall health risks associated with marijuana?

A lot is still unknown because marijuana is illegal under federal law, and that often makes it difficult to do research, said Collins, who worked on a 2017 National Academies of Sciences, Engineering and Medicine report on marijuana and health.

The report said evidence suggests or indicates that smoking marijuana regularly can lead to chronic cough, increased risk for heart attacks and greater risk of developing social anxiety disorders and schizophrenia. Smoking marijuana during pregnancy is linked to lower birth weight in newborns.

That said, studies linking cognitive and physical health problems to marijuana typically are of heavy users.

“For people who are able to use occasionally, it really hasn’t borne out that it’s problematic,” said Dr. Kevin Hill, an addiction psychiatrist and associate professor of psychiatry at Harvard Medical School.

Marijuana has fewer negative health consequences than alcohol and tobacco, a 2018 state Department of Health report concluded.

What about the effect on adolescents and young adults?

The most important phase of brain development is through age 25, and cannabis use during that time can affect what and how you learn, and have long-term implications, Collins said. Marijuana use is highest among people in their late teens to early 20s, a federal survey shows, and that is “actually the worst time to disrupt the development of your brain,” Collins said.

Is it legal to smoke marijuana in public?

It's generally legal to light up on sidewalks and other places cigarettes are permitted.

“The law essentially made it legal to smoke cannabis anywhere where you are allowed to smoke tobacco,” said John Kagia, director of policy for the state Office of Cannabis Management.

One exception: It is illegal for the driver and passengers to smoke or vape marijuana in a motor vehicle, even if it’s not moving.

It is illegal to smoke or vape marijuana — or tobacco — in state and municipal public parks, beaches and other recreational facilities, as well as on federal land, and in private businesses. The state plans to issue licenses for “social consumption spaces,” similar to cigar lounges, Kagia said.

Public outdoor smoking is allowed in part because children and others can be exposed to indoor smoke and vapor, and leases and rules prohibit all smoking inside some private and public-housing apartments, Kagia said.

Even so, he said, just because the law allows use in most public spaces doesn't mean you should light up anywhere. “We urge New Yorkers to be good neighbors," he said. "Just be mindful of where you’re consuming in public settings."

Is the store down the street from me selling cannabis doing so legally?

Probably not. There currently are only 13 state-licensed recreational marijuana dispensaries open in New York, none on Long Island, according to the cannabis office; others are slated to open on Long Island and elsewhere in the coming months.

The Shinnecock Indian Nation in Southampton has granted one license for cannabis sales and has eight other applications pending, Newsday recently reported. The cannabis office has said that federally recognized tribes can allow marijuana sales outside state regulations.

Armed with new enforcement powers, the cannabis office is planning “a significant ramp-up” in the coming weeks to stop illegal sales, Kagia said.

In Nassau County, where no town has authorized sales, about 60 stores have been cited for illegally selling marijuana since the state legalized cannabis use, Nassau County Police Department spokesman Lt. Richard LeBrun said. 

The Suffolk County Police Department said in an email that it does not keep track of the number of stores in the county cited for illegal sales.

Is there any difference between the cannabis sold in licensed and unlicensed stores?

Yes. Unlicensed products “may be tainted with other things that you do not want to ingest, both from a lung health issue and from a behavioral issue,” Collins said. Some illegal marijuana has been found laced with the dangerous and potentially deadly drug fentanyl, she said.

State law requires that all cannabis sold at a licensed store be tested by a laboratory for contaminants and other materials, and to measure potency.

“The rollout of regulated retail outlets in New York has been abysmally slow,” Collins said. “What that’s done is left the illegal stores to just fill in the gaps, the vacuum.”

Is it safer to smoke, vape or eat cannabis edibles?

Smoking and vaping carry the most risks, although vaping may be “slightly better,” Collins said.

Edibles don’t expose the lungs to particulate matter or chemical vapor, she said. But they take much longer to produce a high, so some people eat too much, she said.

Cannabis is dangerous for children, so make sure you keep edibles out of their reach, Collins said.

What are the medical benefits of marijuana use?

There is evidence cannabis treatment can lead to a significant reduction in symptoms for people with chronic pain and multiple sclerosis, and that it can prevent and treat chemotherapy-induced nausea and vomiting, the National Academies report found.

By David Olson

david.olson@newsday.com@DavidOlson11

David Olson covers health care. He has worked at Newsday since 2015 and previously covered immigration, multicultural issues and religion at The Press-Enterprise in Southern California.