Forty-percent of the injuries linked to electric scooter use involve knocks to the noggin while nearly 95 percent of riders don’t wear helmets, according to a first-of-its kind study published Friday, January 25.

As electric scooters and bike shares zoom into cities across the country, health experts are chasing after the potential public health and safety issues circling the micromobility market. The new study, published in JAMA Network Open, is the first to try to track the pattern of injuries linked to electric scooters.

“[M]any thousands of riders are now using standing electric scooters daily on US streets shared with millions of pedestrians and drivers,” the authors—a group of researchers at University of California, Los Angeles—write. They also note that the new transport trend is only expected to speed up, with dockless electric scooter service Lime valued at $1.1 billion and its rival Bird valued at more than $2 billion. “Therefore, understanding the impact of rising scooter use on public health is more important than ever,” the researchers conclude.

To catch some of the first injury-related data, the researchers monitored medical records at two UCLA-affiliated emergency departments for a year, skimming for scooter injuries. They nabbed 249 reports of injuries involving electric scooters between September 1, 2017 and August 31, 2018. For comparison, they identified 195 bicycle injuries and 181 pedestrian injuries at the emergency departments during the same time frame.

Of those injured in scooter-related accidents, 58 percent were male and the mean age was 33.7 years old. Nearly 92 percent of the injured were people riding a scooter at the time of their injury. The remaining were non-riding pedestrians, including 11 who were hit by scooters and five who tripped over parked scooters.

The most common type of injuries recorded were head injuries, accounting for 40 percent of scooter injuries overall, the researchers found. Though most were not serious cases and the injured were discharged home from the emergency room, two cases were severe and admitted to intensive care. Other common injuries included bone fractures (32 percent) and the grouping of contusions, sprains, and lacerations (28 percent).

Only 10 of the injured riders were documented as wearing a helmet. And in a series of public observation sessions, researchers noted that nearly 95 percent of riders weren’t wearing helmets despite local laws requiring helmet use.

With the low helmet use and high head-injury rate, the researchers are hoping the data can inform health policy. The finding is timely, they note, as California just signed into law a Bird-supported bill that removes helmet requirement for electric scooter riders over aged 18.

In an accompanying editorial, Frederick Rivara, an injury prevention expert at the University of Washington, emphasized that health researchers weren’t trying to rain on the scooter parade with the injury data. “We are not troglodytes trying to stuff the genie back in the bottle,” he wrote. But, Rivara said, health experts should work with micromobility companies, helmet manufacturers, and policy makers to address safety.

“We as purveyors of health care and public health should partner with these other players to ensure that these companies are not creating a new public health problem,” he concluded.

JAMA Network Open, 2018. DOI: 10.1001/jamanetworkopen.2018.7381 (About DOIs).