WEDNESDAY, Jan. 22, 2014 (HealthDay News) — Even very low blood levels of alcohol increase the risk of deadly car crashes, a new study finds.

Drunk driving laws need to be updated to reflect this fact, the researchers contend.

They examined data from more than 570,700 fatal traffic crashes in the United States between 1994 and 2011, and focused on drivers with a blood alcohol level of 0.01 to 0.07 percent, which some refer to as “buzzed driving.” Legally, a driver is considered drunk once blood alcohol levels reach 0.08 percent.

Drivers with a blood alcohol level of 0.01 percent — well below the legal limit — were 46 percent more likely to be officially and solely blamed for a crash than the sober drivers they collided with, according to the study led by sociologist David Phillips, at the University of California, San Diego.

“We find no safe combination of drinking and driving — no point at which it is harmless to consume alcohol and get behind the wheel of a car,” Phillips said in a university news release.

There is no sudden switch from being blameless below the legal limit to being blamed once over the legal limit, the researchers also found. Instead, blame rose steadily as blood alcohol levels increased from 0.01 to 0.24, according to the study published online recently in the journal Injury Prevention.

Drivers with blood alcohol levels between 0.01 to 0.07 often don’t receive more severe punishment than sober drivers involved in crashes, the researchers noted.

Police, judges and the general public treat a blood alcohol level of 0.08 percent as “a sharp, definitive, meaningful boundary,” and don’t impose harsh penalties on drivers with alcohol levels below that, Phillips said. He added that perspective needs to change.

“Our data support both the National Highway Traffic Safety Administration’s campaign that ‘Buzzed driving is drunk driving’ and the recommendation made by the National Transportation Safety Board, to reduce the legal limit to [blood alcohol level] 0.05 percent,” Phillips said. “In fact, our data provide support for yet greater reductions in the legal [blood alcohol level].”

More than 100 countries already set their legal blood alcohol level limits at 0.05 percent or lower, according to the news release.

More information

The U.S. Centers for Disease Control and Prevention has more about impaired driving.