This is Scientific American — 60-Second Science. I'm Christopher Intagliata.
There are thousands of gun shows in the U.S. each year—swap meet–type gatherings where the sellers' tables are covered in guns, ammunition, accessories, books.
Just as varied as the wares, are the laws that govern what's legal at the shows. California requires background checks for all buyers, even when purchasing guns from private citizens, rather than licensed dealers. Nevada does not.
So researchers treated the situation as an inadvertent experiment. They tracked gun deaths and injuries in California communities within a couple hours' drive of the Nevada border, before and after hundreds of gun shows in the two states.
They saw no increase in deaths or injuries in the weeks following California gun shows. But after shows in nearby Nevada, the number of hurt and killed citizens in those same California communities climbed 70 percent, compared to pre–gun show levels.
That translates to 30 additional deaths and injuries in those California zip-codes, during the decadelong study period. "If we extended this study nationwide, it's possible that the number of deaths and injuries associated with gun shows could really add up." Ellicott Matthay, an epidemiologist at U.C. Berkeley, who led the study.
Her team's analysis appears in the Annals of Internal Medicine.
Matthay says the results suggest California's stricter laws may be effective in preventing some gun-related injuries. But: "It also suggests that travel to less restrictive states may threaten the effectiveness of firearm laws within California."
But that situation may change. Because Nevada voters approved more restrictive background checks for private gun sales last year. The law has yet to be implemented. But if it is, it'll be a longer drive for gun buyers looking to skirt their local laws.
Thanks for listening for Scientific American — 60-Second Science Science. I'm Christopher Intagliata.
就像这些商品一样，枪支展规定的管控枪支法律也是多种多样的 。加利福尼亚州要求对所有枪支买家进行背景调查，即使从私人而不是特许经销商那里购买也不例外 。而内华达州则没有这种规定 。
因此，研究人员将这种情况视为一种无意实验 。他们对加州社区发生的枪支致死致伤事件进行了追踪，那里距离内华达州边界约几小时车程，他们在两个州举行数百次枪支展的前后进行了追踪 。
他们发现，在加州枪展后的几周内，伤亡人数没有增加 。但是，在邻近的内华达州枪展之后，相同加州社区的伤亡人数比枪展前增加了70% 。
这样一来，在长达十年的研究中，这些加州社区的伤亡人数上升了30% 。“如果我们在全美开展这项研究，那枪展可能真的会使死伤人数增加 。”埃利科特·马特海是加州大学伯克利分校的流行病学家，她也是这项研究的领导者 。
马特海表示，研究结果表明加州较为严格的法律也许可以有效地避免一些与枪支有关的受伤事件 。但是，“研究还表明，去管理较松的地方旅游可能会威胁加州枪支法律的效力 。”
但是，这种情况可能会改变 。去年内华达州选民投票通过了一项法律，对私人枪支销售进行更严格的背景审查 。但是，该法律尚未实施 。如果开始实施，那枪支购买者将要开更长时间的车程来躲避当地法律 。
谢谢大家收听科学美国人——60秒科学 。我是克里斯托弗·因塔利亚塔 。
1. rather than 而非；胜于；而不是；
例句：The opposition appear to have chosen the path of cooperation rather than confrontation.
2. treat as 对待；看待；处理；
例句：Police say they're treating it as a case of attempted murder.
3. compared to 与…相比；和…比起来；
例句：He's a mere slip of a lad compared to his brother.
4. add up 增加；
例句：It's the little minor problems that add up.