美国国家公共电台 NPR To Repel Ticks, Try Spraying Your Clothes With A Pesticide That Mimics Mums（在线收听）

DAVID GREENE, HOST:

We have been reporting on the rise of some really nasty diseases caused by tick bites - everything from Lyme disease to Rocky Mountain spotted fever. Well, now a new study is shedding light on an old technique to repel ticks that many people don't use. It is a repellent that you spray on your clothing and not on your skin. And here's more from NPR's Allison Aubrey.

ALLISON AUBREY, BYLINE: Back in the 1980s, the U.S. military tested the use of a pesticide derived from the flowering chrysanthemum plant to protect soldiers from insect and tick bites. It's called permethrin, and now decades later, many outdoor enthusiasts use it, including Danny Quinteros.

DANNY QUINTEROS: I love being outside, whether it's hiking, backpacking, climbing.

AUBREY: He's got a plan to hike the Appalachian Trail, which cuts through many tick-infested areas, so he's got a can of permethrin, and he's about to spray it on a T-shirt.

QUINTEROS: What you want to do is to stay back 6 to 8 inches away from the clothing.

(SOUNDBITE OF SPRAY)

AUBREY: He applies an even coat, then flips it over to spray the back.

QUINTEROS: Just one single layer is fine.

AUBREY: He says, in combination with skin repellent that he sprays on his exposed skin, he's found that permethrin-treated clothing really works. And there's a fair amount of science to back him up. Neeta Connally oversees the Tickborne Disease Prevention Lab at Western Connecticut State University.

NEETA CONNALLY: There are several studies now that provide pretty compelling evidence that wearing permethrin-treated clothing has the potential to reduce tick bites.

AUBREY: The most recent comes from a study done by researchers at the Centers for Disease Control and Prevention. They purchased a bunch of pretreated clothing. These are garments treated with permethrin by the manufacturer. Lars Eisen is the study author. He explains, they tested different species of ticks on the clothing, including blacklegged ticks, also known as deer ticks, which can transmit the bacteria that causes Lyme disease.

LARS EISEN: We wanted to see how long they have to be in contact with the treated clothing to be incapacitated and die.

AUBREY: Eisen says when the blacklegged nymphs came into contact with the treated clothing...

EISEN: It took them less than a minute to receive a dose of permethrin that killed them.

AUBREY: Even though they don't die right away, the permethrin quickly incapacitates them, so they're unable to bite. So why don't more people use permethrin? Neeta Connally says her research suggests that many people don't know about it, or they're hesitant to use a pesticide on their clothing. But there's evidence it's safe. It's the same chemical that many of us have put on our kids' heads to treat head lice.

CONNALLY: When, you know, I think of the potentially serious illnesses that my family members or I could get from a single tick bite, I feel very comfortable wearing treated clothing.

AUBREY: The benefits outweigh the risks. Allison Aubrey, NPR News.