Fifty mosquito repellent products, including mosquito repellent patches and wristbands, prove to be of little help, said Beijing quality supervision¹ authorities after conducting sample tests recently.

近日，北京市质监局对包括驱蚊贴和驱蚊手环在内的50款驱蚊产品进行抽样检测后发现产品无一有效。

Bought from online and offline stores, these new mosquito repellent products, with price tags varying from 5.2 to 66 yuan, all boasted a plant-based formula with a long effective duration for babies and pregnant women.

这些新型驱蚊产品是从线上和线下商店购买的，价格从5.2元至66元不等，均号称采用植物配方，驱蚊效果持久，儿童和孕妇适用。

The result is obvious and disappointing. These products, regardless of a touted² period of effectiveness ranging from five hours to 60 days, did very little in preventing mosquitoes.

检测结果是显而易见且令人失望的。这些产品，不管有效时间是5小时还是60天的，都在驱蚊方面收效甚微。

Scientists noted³ that the dose of citronellol, an oil used for keeping insects away, in mosquito repellent products is the key factor in assessing its effectiveness.

科学家们曾指出，驱蚊产品中的香茅醛（一种被用来驱虫的油剂）的剂量是评估其驱蚊有效性的关键因素。

Among the 50 samples, 14 of them did not have citronellol, while the rest reportedly had the ingredient but at amounts below the standard.

据报道，50份样品中的14份根本不含香茅醛，其他样品中虽然含有香茅醛，但剂量低于标准。

Those repellent patches and wristbands that claim to ward⁴ off mosquitoes are not friendly to babies and pregnant women, a group that these products target.

那些声称能驱蚊的驱蚊贴和驱蚊手环，实际上对婴儿和孕妇并不友好，而这些产品所瞄准的正是这一群体。

Researchers said the so-called plant-based and non-toxic products on the market have yet to undergo scientific testing, which is why vulnerable groups are not advised to use such repellents.

研究人员表示，市场上所谓的植物性和无毒产品还没有经过科学测试，这就是为什么不建议弱势群体使用这种驱蚊产品。