Fatal bicycle accidents are often linked to alcohol consumption, according to a report published today in the Journal of the American Medical Association. Researchers from Johns Hopkins University studied 466 Maryland bicyclists and found that one in three fatally injured riders had elevated blood alcohol levels at the time of their accident. The team also found that a blood alcohol concentration of 0.08 gram per deciliter, the legal level of drunkenness in most states, increased the cyclist's risk of serious or fatal injury by 2,000 percent.

Significantly, only 5 percent of injured bikers who had been drinking wore helmets. "It's a double jeopardy," says Guohua Li, lead author of the study. "Those who ride under the influence are most in need of protection, yet in our study, they were least likely to wear helmets." (As surprising as the new results are, alcohol may play an even more prominent role in biking injuries: this study did not consider those injuries that occurred at night, which is when 56 percent of fatal biking accidents take place.)

Exactly why people are boozing and biking isn't entirely clear, but 30 percent of the injured riders who had elevated blood alcohol levels also had received citations for driving while intoxicated. The authors suggest that in some cases the people in their study may have been traveling by bicycle because their driver's licenses had been suspended. Whatever the reasoning, the risk associated with bicycling under the influence is sobering. "Alcohol abuse and bicycling," says team member Susan P. Baker, "is an increasing public health problem that warrants more enforcement."