When drug users buy heroin on the streets of Baltimore, they don't know whether it also contains fentanyl, a synthetic painkiller so powerful that small amounts can kill.
Now the city plans to tell them when and where the heroin is likely to be adulterated.
By using real-time overdose data from emergency responders, city health officials plan to identify fentanyl hot spots and head there with warnings. They will inform providers of drug treatment and services to the homeless, area residents and others, who can share the information with drug users or people who know them.
The city health department spearheaded creation of a fentanyl task force, which brings together representatives of several city agencies.
"It's so dangerous that getting ahead of this as much as we can is crucial," health department spokesman Sean Naron said. "Users are very scared of fentanyl, but they don't always know it's there."
The number of fentanyl-related fatal overdoses in Baltimore increased tenfold from 2013 to 2015. The city suffered 260 heroin-related overdose deaths last year and 160 fentanyl-related deaths.
The U.S. Drug Enforcement Administration believes the fentanyl is made in labs overseas and mixed into heroin here because it is cheaper. A dose sold as heroin can be entirely fentanyl.
The task force is the latest move by the city and state health departments to counter rising overdose deaths. Officials have sought to increase access to treatment and have trained an army of private citizens to use the opioid overdose antidote naloxone.
City officials have urged opioid users to avoid taking the drugs alone so someone is able to revive them with naloxone if they overdose.
"Overdoses continue to kill more people in our city than homicide, and quality, on-demand treatment remains out of reach for the vast majority of those suffering from addiction," Dr. Leana Wen, Baltimore's health commissioner, said in a statement. "We would never tolerate this for any other disease, so we must strengthen our efforts to ensure that no more lives are lost to this devastating disease that affects individuals, families and communities."