Crack cocaine smoking too may be legal in the only city in North America where addicts can shoot heroin into their veins at a government-sanctioned injection site.
Officials in Canada's westernmost British Columbia province are touting the idea of opening up an existing smoking room at Vancouver's Insite centre, but stress it is currently only at the "concept stage."
British Columbia provincial health officer Perry Kendall told AFP: "There's a growing amount of evidence that smoking crack cocaine increases the risk of contracting HIV."
The British Columbia Centre for Excellence in HIV/AIDS is the latest to make the link in a study published Tuesday in the Canadian Medical Association Journal.
"By taking addicts off the street and allowing them access to supervised smoking rooms, we could reduce the risk while putting them in contact with health workers" and potentially break their drug habit, Kendall said.
In turn, this would reduce the spread of HIV/AIDS, he said.
The study did not pinpoint the cause of higher incidence of HIV infection among crack cocaine smokers.
But it suggested these individuals may be taking more risks, such as participating in unsafe sex, during crack cocaine binges. They may also attract more HIV-positive individuals into their social groups.
As well, wounds in and around the mouth of addicts often caused by the use of metal or glass pipes may make them more vulnerable to HIV transmission during activities such as oral sex or pipe sharing, said the study.
"I think now is the right time," Kendall said. "We know what the problem is. We just need to address it."
In recent years, cities across Canada have experienced an explosive increase in the use of crack cocaine, whereas the use of other illicit drugs such as heroin appears to be on the decline, said researchers.
Vancouver's Insite facility opened in 2003, but its drug smoking room was never opened as evidence was lacking to support such an approach to treat crack cocaine abuse.
Also, the facility's exemption from Canadian laws allowing it to host heroin users is specific to those clients only -- not crack cocaine users.
The federal government has been fighting in court to revoke Insite's special permission to operate, granted by a previous administration.
As well, there remain unresolved concerns for staff about second-hand smoke from crack cocaine inhalation, said Kendall.