27
Jul
Researchers Develop Pesticide-Free, Mosquito-Proof Clothing
(Beyond Pesticides, July 27, 2021) Researchers at North Carolina State University have developed pesticide-free clothing able to prevent 100% of mosquito bites for the wearer, and published proof of the garment’s effectiveness in a study in the journal Insects. If able to be scaled at a commercial level, the fabrics have the potential to transform personal protective measures for mosquitoes, which often includes in well-meaning consumers spraying toxic pesticides like DEET and permethrin on their body and clothing. “The fabric is proven to work – that’s the great thing we discovered,” said study co-author Andre West, associate professor of fashion and textile design at NC State and director of Zeis Textiles Extension for Economic Development in a press release. “To me, that’s revolutionary. We found we can prevent the mosquito from pushing through the fabric, while others were thick enough to prevent it from reaching the skin.”
To create the mosquito-proof fabric, scientists turned to physics and mathematical models, rather than looking for new killer chemistries. “Our premise here is: why do we need an insecticide-treated textile when you can do it, now that you know a mathematical formula, without chemistry?” said Michael Roe, PhD, an N.C. State professor of entomology to the News and Record. Scientists analyzed the mosquito’s morphology, looking for weaknesses that could be addressed by various textiles. Measurements were taken on the mosquitoes’ head, antenna, proboscis and other mouth parts. Then, textile models were with differing pore sizes and thicknesses were developed to address different aspects of the mosquito’s morphology. One had pores small enough to stop the proboscis from entering the skin, another stopped the mosquito from getting its head close enough to the skin, and the third had larger pores but was thick enough to stop skin contact.
Scientists then developed three fabrics based on the models to test in the real world. One was a superfine knit, another was knit, double layered and bonded, and the last fabric was a knit three-dimensional fabric, and thus thicker than the other two. Lab testing found that the fabrics developed by researchers provided bite resistance of 95% or greater.
Scientists then compared the success of their model textiles to the use of permethrin-treated clothing, a common insecticide which, despite being classified as having suggestive evidence of carcinogenicity, is often impregnated in or sprayed onto clothing in attempts to ward away mosquitoes. Results showed that while the pesticide-free woven textiles maintained bite resistance to 95%, permethrin treated clothing’s bite resistance was as low as 80%. Although more mosquitoes landed on the woven clothing, fewer were able to penetrate and reach the skin. And while the permethrin-treated clothing had fewer mosquito landings, those that were able to get near the skin were also able to extract a blood meal.
To ensure their textiles worked outside of the lab, two pieces of bite-proof clothing were constructed – a thin underlayer shirt, and a thicker military style shirt. These garments were tested by having a individual wear the clothing and walk into a cage filled with mosquitoes. For the military-style shirt, bite resistance was 100%. For the underlayer, 96.5% bite resistance was achieved, showing 7 bites out of 200 mosquitoes. Researchers indicate that another layer of clothing would result in 100% effectiveness, and some tweaks to the original garment were also able to achieve this goal. In addition to successfully eliminating mosquito bites, the study indicates that the clothing was comfortable, and still provided good breathability.
“The final garments that were produced were 100 percent bite-resistant,” said Michael Roe, PhD, William Neal Reynolds Distinguished Professor of Entomology at NC State. “Everyday clothing you wear in the summer is not bite-resistant to mosquitoes. Our work has shown that it doesn’t have to be that way. Clothes that you wear every day can be made bite-resistant. Ultimately, the idea is to have a model that will cover all possible garments that person would ever want – both for the military as well as for private use.”
Eliminating the military’s use of insecticide-treated clothing would be an important step forward in protecting US military members. Previous research has found that combinations of DEET and permethrin used in clothing worn by US service members may have played a role in the development of Gulf War syndrome, a disease characterized by chronic symptoms, including headache, loss of memory, fatigue, muscle and joint pain, and ataxia, which causes an inability to coordinate muscular movements.
Reports indicate that the company Vector Textiles has licensed the patent rights for the garments, and has begun to prototype new clothing, including a pesticide-free mosquito-resistant infant onesie.
While waiting for this revolutionary mosquito-avoidance method to hit the market, continue to take protective measures that do not include the use of DEET, permethrin and other toxic insecticides. Long-sleeve light colored clothing, coupled with least-toxic repellants can adequately address outdoor nuisance mosquitoes. Yard, neighborhood, and community-based measures to remove standing water around properties and encourage neighbors to do the same can also have a dramatic effect at reducing numbers of nuisance biting mosquitoes.
For more information on how to stop the bite, see Beyond Pesticides program page on Safer Mosquito Management. If you’d like to begin educating your neighbors and community about safer ways to manage mosquitoes without the use of toxic insecticides, let the Mosquito Doorknob Hanger help you start the conversation.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: NC State University (press release), Insects (peer-reviewed journal)
Seems like they only tested mosquitoes. Sandflies and ticks also carry disease. Would these fabrics be helpful for that too? Seems to me that would be essential to replace treated military clothing.
August 19th, 2021 at 8:13 pmIt’s interesting when you said that resistance is important to prevent insect bites. My wife told me that she is looking for bug repellent clothing for our camping trip next week, and she asked if I have any suggestions on where to buy it. Thanks to this useful article, I’ll be sure to consult trusted protective clothing that can keep us safe from insects.
March 15th, 2022 at 9:14 pm