A new study finds U.S. adults increasingly perceive daily smoking and secondhand exposure to marijuana smoke as safer than tobacco smoke, views that do not reflect the existing science, CNN reports.

Researchers at the University of California, San Francisco surveyed more than 5,000 adults. They compared public perceptions of the safety of marijuana smoke versus tobacco smoke in 2017, 2020 and 2021. The study found adults increasingly viewed marijuana as safer than tobacco over time. In 2017, 36.7% percent of participants felt daily marijuana smoking was safer than tobacco smoking. By 2021, that had increased to 44.3% of adults surveyed.

Adults who were younger or not married were more likely to think marijuana was safer, while those who were retired were less likely to think so.

“When you burn something, whether it is tobacco or cannabis, it creates toxic compounds, carcinogens, and particulate matter that are harmful to health,” said lead study author Dr. Beth Cohen. “It’s the combustion that’s the problem, so this idea that because cannabis is ‘natural’ burning and inhaling it is fine is just wrong.”