Drug tests required for people on parole or probation often fail to detect the use of synthetic marijuana, a substance that is increasing in popularity, according to a pilot study recently released by the White House Office of National Drug Control Policy.

The study, conducted by the ONDCP and the University of Maryland’s Center for Substance Abuse Research across three sites in the District, Virginia and Maryland, prompted calls for updated testing.

“Most drug tests are testing for the old epidemics, and they need to update their panels,” said Eric Wish, director of the center and the principal investigator in the study. “This is not only for the criminal justice system but the public health system as well.”

Authorities have said they are investigating whether three deaths in Colorado in early September were linked to synthetic marijuana, and there has been an uptick of emergency-room admissions linked to its use.

Figures from the Drug Abuse Warning Network showed that in 2010 there were 11,406 ER admissions related to synthetic cannabinoids. That number more than doubled in 2011, to 28,531.

The substances — which have hundreds of names, including K2 and Spice — are sold in colorful packets for between $9 and $12. They contain psychoactive substances, chemically similar to the active ingredient in marijuana, that are applied to plant material and smoked. Some studies have suggested that the synthetic substance can be more potent and addictive than marijuana.

The researchers, who tested a sample of young men who are in the D.C. parole and probation system, found that 39 percent of them tested positive for synthetic cannabinoids but passed a traditional drug screen. That number was lower among those tested from the Chesterfield Community Corrections Services in Chesterfield County, Va., at 20 percent, and among those tested from the Prince George’s County Drug Court, at 13 percent.

“For the first time, we found a drug that was as likely to be found in persons who had failed the limited criminal justice system screen as in persons who had passed,” the report said.

Researchers said the findings suggest not only that people in the criminal justice system are unlikely to be flagged for the use of synthetic marijuana, but that the same is true of people who undergo routine testing, such as some hospital workers, military personnel and others who are tested in their workplaces.

“You have people coming into these places exhibiting strange behaviors, and they enter the public health system looking for help, but the doctor may not know what is wrong with the person,” Wish said. “The public health system needs to start looking at these new metabolites to screen for them.”

Wish also said that expanding testing could help to identify people who take synthetic cannabinoids in order to avoid detection.

Altering testing panels may run into roadblocks at a time when federal, state and local agencies are facing budget cuts.

None of the three sites for the project included screening for synthetic marijuana, and the special testing for the study cost an average of $63 per specimen. More than 1,000 specimens were tested.

Despite this, Rafael Lemaitre, associate director for public affairs at the ONDCP, said the agency hopes that the study will spur state and local officials to stay ahead of emerging trends related to synthetic drugs.

“We hope these findings will help state and local officials have a greater awareness regarding the prevalence of synthetic drugs in their communities as they seek to stop the revolving door of our criminal justice system by guiding more offenders into treatment,” Lemaitre said.