SAN FRANCISCO (KGO) -- There has been a dramatic spike in the number of injuries among people who ride electric scooters, according to a study done by UCSF.
RELATED: Only 4% of electric scooter riders injured in accidents were wearing helmets, study finds
In California, lobbyists for the e-scooter companies fought hard against helmet laws that would have protected people.
From 2014 to 2018 the number of scooter-related injuries and hospital admissions in the U.S. quadrupaled, growing by 222% percent. The number across the board was 39,000 injuries.
RELATED: SF officials to vote on scooter legislation after injuries, pain for neighbors
Dr. Benjamin Breyer of UCSF Health compiled the data collected from hospitals across the country.
"The thing that I thought was the most striking is one in three people that came to the emergency room had a head injury," Breyer said.
That's twice the rate of head injuries for bicyclists, but many resist the idea of wearing a helmet.
"They don't go that fast and they dont come with a helment, and I'm not going to bring my own helmet," Jamar Jasper, an e-scooter rider said.
Breyer said, "the group that got injured the most were 18 to 34-year-olds."
The push to allow people over 18 to without helmets began 80 miles from San Francisco, in Ripon, a city in the Central Valley.
Assemblyman Heath Flora introduced AB 2989 requiring only those under 18 years of age to wear a helmet. The argument was, if adult bicyclists aren't told to wear helmets, stand-up motorized scooter riders shouldn't have to either.
The bill was signed by then Governor Jerry Brown in September 2018.
One of the e-scooter companies, Bird, gave us this statement: "We provide them to riders for free and to date, we have given away more than 65,000 helmets."
Enrique Sigui wasn't wearing a helmet when he was involved in an accident. He does now.
"Just to protect myself when I go in traffic," Sigui said. "If I fell, the part that is going to get hurt the most is the head, so a helmet is a good idea."
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Dramatic spike in electric scooter injuries across US, report says