As global attitudes about cannabis shift towards a more liberal, legalized future, one British researcher is speaking up about the dangers of U.K. teen cannabis use. The thing is, he’s not concerned about the weed, but instead how much tobacco is being added to British spliffs.

According to the Daily Mail, Ian Hamilton, a researcher at York University, has made it his goal to bring attention to the severe health threats caused by mixing tobacco with weed, even going as far as calling spliffs, or mole bowls, a gateway drug to nicotine addiction.

“Even if they quit using cannabis they may find they experience tobacco withdrawal.” Hamilton said about teenage spliff smokers. “They also expose themselves to all the other health risks associated with tobacco such as cancer, heart disease and respiratory problems.”

Instead of pushing tired rhetoric about the dangers of cannabis, Hamilton is using a collective interest in marijuana to restart the conversation about the ever-present dangers of tobacco.

“'If we accept that millions of people will carry on using cannabis then we should encourage them to use cannabis in ways that avoid tobacco and minimise harm to their health.” Hamilton told the Daily Mail.

“We urgently need to provide clear public health messages in a way that young people will engage with.”

Perhaps legalizing and normalizing cannabis would do the trick?