Stephanie L. Richards, MSEH, PhD, East Carolina University;
Jo Anne G. Balanay, PhD, CIH, East Carolina University;
Jonathan W. Harris, MSEH, East Carolina University;
Victoria M. Banks, East Carolina University;
Steven Meshnick, PhD, University of North Carolina at Chapel Hill
Biological hazards such as exposure to ticks and mosquitoes can affect health. Permethrin-treated clothing
is available to the public. We don’t currently understand, however, the effects of environmental factors such as
fabric type, washing, sunlight, and temperature on permethrin content in treated clothing with respect to mosquito
knockdown and mortality. We evaluated the extent to which fabric type (100% cotton denim jeans, 100%
polyester work shirt, 35% cotton/65% polyester work shirt), light exposure (0 or 100%), temperature (18 °C, 32 °C), and number of washes (0, 3, 12, 36) affected mosquito knockdown 2 hours post-exposure, mosquito mortality
24 hours post-exposure, and permethrin content.
All fabrics used in this study were treated with permethrin at a concentration of 125 μg/cm2. Denim fabric
having no washes and no light exposure showed the highest amount of permethrin. Washing and light exposure
significantly reduced the ability of permethrin-treated fabrics to induce mosquito knockdown and/or mortality
under the simulated conditions used for this test. Temperatures tested did not affect permethrin content or
mosquito knockdown and mortality. Long-lasting impregnation of uniforms protects against mosquito bites under
simulated laboratory conditions. Employers and employees should consider the use of permethrin-impregnated
clothing and uniforms in addition to daily repellent sprays.
Editor note-The complete study, with the abstract above, may be viewed at the following link: www.neha.org/sites/default/files/jeh/JEH4.17-Feature-Residual-Effectiveness-of-Permethrin-Treated-Clothing_with-cover.pdf. This article was originally published in the Journal of Environmental Health, April 2017 (Volume 79, Number 8).
Posted with permission from the Journal of Environmental Health, a publication of the National Environmental Health Association, www.neha.org .