众所周知，保护雨林有益于保持生物多样性。可你是否知道这也对人体健康大有益处？本周《新发传染病》上刊登的一篇文章指出，这是因为砍伐树木越少就有可能使疟疾发作的越少。森林覆盖面积仅减少4%就能使疟疾发病率提高50%。
You know saving the rainforest is good for biodiversity. But it may also be a boon to human health. That's because less clear-cutting may mean less malaria, according to a paper out this week in the journal Emerging Infectious Diseases. Researchers looked at stats for 2006 from 54 health districts in western Brazil. The sites had more than 15,000 cases of malaria. The investigators compared those cases to deforestation in the same health districts over the previous 10 years. They found that a loss of just four percent of forest cover was associated with nearly 50 percent more malaria cases. And malaria risk was highest five to 10 years after the jungle was cleared. Not all mosquitoes carry malaria. But the human-loving species Anopheles darlingi does, and previous studies have shown that it thrives in disturbed areas. In fact, you're over 200 times more likely to find one of them biting you in a clearing than you are deep in the jungle, where other more benign species compete with them for blood. So how much clear-cutting is too much? We don't know yet - but an intact swath of rainforest appears to provide free public health services. -Christopher Intagliata
众所周知，保护雨林有益于保持生物多样性。可你是否知道这也对人体健康大有益处？本周《新发传染病》上刊登的一篇文章指出，这是因为砍伐树木越少就有可能使疟疾发作的越少。 研究人员对巴西西部54个卫生区在2006年的统计数据进行了研究，这些区域有15000多例疟疾病患。研究人员将过去10年间同一卫生区里的疟疾病例与毁林开垦的情况作了比较，发现森林覆盖面积仅减少4%就能使疟疾发病率提高50%，而当这些热带丛林被砍伐殆尽的5至10年间，疟疾的发病率升至最高点。 并非所有的蚊子都携带有疟疾病毒。但酷爱叮人的达[林]氏按蚊可不是省油的灯，它们个个都携带疟疾病毒，而且先前的研究表明它们在人类活动强干扰地区（林木砍伐严重地区）更加肆虐。要知道，你在树木全被砍伐而光的林地被这种蚊子叮上一口的几率可是在丛林深处的200倍！密林莽丛中同样嗜血的生物跟这些疟蚊比起来可要仁慈得多。 那么，伐林砍木多少算是过度了呢？现在还不清楚——但是一片完整的雨林却可以极大地改善公共健康哦。