It was almost like telling them that obesity is good for you. Facing a lecture hall full of public health experts, Dr. Shaul Katzir, a historian at Tel Aviv University's Porter School of Environmental Studies, claimed Monday that a new Knesset law requiring bicycle riders to wear helmets was wrong and would harm public health as many would give up riding instead. Speaking at the Health Ministry's 13th annual conference on education and health promotion at Kibbutz Ma'aleh Hahamisha, Katzir raised the ire of most of the hundreds of audience members who were convinced the law would minimize brain and head injuries incurred by bicyclists, as well as skaters, rollerbladers, and skateboarders. Katzir, a devoted biker, delivered his lecture right after that of Liri Andy-Findling of Beterem, the national child safety and health organization that fought to pass the law, which went into effect in July. Andy-Findling declared that bicycle helmets have been shown to reduce harm to the head and brain, in the case of an accident, by 88 percent. A total of 660 children and youth were hospitalized last year with injuries received while riding bikes and other wheeled devices. In its fight for mandatory helmets, Beterem created a broad coalition of government ministries, the Israel Police, hospital neurosurgeons, medical societies and public organizations, all of whom backed the law. A survey conducted for Beterem found that 75% of a representative sample were aware of the law even before it went into effect, and 92% were in favor of it. Bicycle and toy shops were told to inform customers that they needed to wear helmets when biking or skating. Andy-Findling said the Israel Police reported increased use of helmets even before it began fining violators. But Katzir, who conducted his "research on the danger of the law" with TAU colleague Dr. Daniel Mishori, told the audience that "We think bikes are among the best ways to exercise and the best means for active transportation. But even if helmets gave 100% protect[ion] to the whole body, which they don't, forcing people to wear them by law will cause a decrease in use by 10% and cause harm to public health." Helmets, he argued, are uncomfortable, especially during Israeli summers, and riders don't like the inconvenience of carrying them along. Katzir said helmets reduce injuries when a rider falls and the impact to his or her head comes at no more than 20 kilometers per hour, but have little protective effect when he is hit by a vehicle. The law, he said, was more suited for Holland or Denmark, where bikers fall but rarely collide with vehicles. Katzir concluded that it should be "left to riders, especially adults, whether to wear helmets in the city. In rural areas, they should be worn because they will help riders." Although some participants were persuaded by Katzir's arguments, others - including the ministry's outgoing head of public health Dr. Alex Leventhal - were furious. Andy-Findling was upset at not being allowed to counter his arguments and maintained that they were "not based on fact." One veteran public health expert who heard both arguments sided with the Beterem representative, saying many falls from bikes in which helmets protected the riders from injury were not reported, creating inaccurate documentation. A Health Page feature on the conference will appear on Sunday, November 25.