The percentage of overdose deaths linked to smoking drugs rose sharply in recent years, overtaking injection as the leading route of drug use involved in such deaths, according to a new report from the US Centers for Disease Control and Prevention.

The report, published Thursday, looked at information from crime scene investigations, witness reports and autopsy data and categorized overdose deaths by evidence of smoking, injecting, ingesting or snorting drugs. Researchers compared data on drug deaths from January to June 2020 with data from July to December 2022. By the end of 2022, smoking was the most common form of drug consumption involved in overdose deaths.

Specifically, the percentage of overdose deaths that involved smoking increased almost 74% – from 13.3% to 23.1% – between 2020 and 2022. During the same time period, the percentage of overdose deaths involving injections fell from 22.7% to 16.1%.

More than 109,000 people died of a drug overdose in the United States in 2022 alone. Nearly 70% of those who died were using synthetic opioids, mostly illegally created fentanyl and fentanyl analogues that are slightly altered – and often deadly – forms of the medically prescribed drug.

Smoking a drug is the quickest way for it to reach the brain. People may have switched from injecting drugs to smoking due to a perception that the overdose risk is lower, according to the report. Users may also have a sense that they have “more control” over how much of the drug they are consuming, the researchers said. Fentanyl, though, is such a powerful drug that even a small amount can be deadly.

Among the other reasons people may have been switching, the CDC report said, is that smoking can have fewer adverse health effects such as abscesses. Fentanyl users often inject it several times a day, and that can wear out their veins; smoking eliminates injection site challenges.

Knowing about this trend can help harm-reduction workers provide users with safer smoking materials, in addition to fentanyl test strips and naloxone, that can reduce the health risks of sharing smoking equipment with other drug users.

Molly Reid, an epidemiologist whose research focuses on access to safer smoking equipment, said that many harm reduction organizations carry syringe service programs, but with this information about smoking, they can expand what they offer.

“Sometimes, if the only thing that people can get is free syringes, they may decide to inject because that’s what they have available,” said Reid, who did not work on the new study.

Reid said it would be good to develop more research that compares the risks of injecting versus smoking fentanyl. If what’s known about the dangers of heroin aligns with fentanyl, “it’s not the fact that people are increasingly smoking drugs that’s driving this overdose trend, it’s that fentanyl is just so deadly.”

“Smoking is still likely safer than injecting, but not enough to make up for the added danger of fentanyl,” Reid said. “We definitely need more naloxone, fentanyl test strips and overdose awareness education out there.”

Drug overdose deaths reached a record high in 2022, according to the CDC, and fentanyl has been a significant factor contributing to the rise. Provisional data published by the agency Wednesday suggests that 2023 is on track to be another devastating year; more than 111,000 people died from a drug overdose in the 12-month period ending in September. Synthetic opioids, primarily fentanyl, were involved in more than two-thirds of those deaths.