In vitro percutaneous absorption of model compounds glyphosate and malathion from cotton fabric into and through human skin

Chemicals are introduced to fabric at many steps during manufacture and use. Fabrics containing chemicals can cause medical problems such as dermatitis and death. Insecticides impregnated into uniforms worn by “Desert Storm” personnel are implicated in ‘Gulf War Syndrome’. These chemicals must get from fabric into and through skin to cause toxic effects. The objective of the present study was to determine in vitro percutaneous absorption of model chemicals glyphosate (water soluble) and malathion (relative water insoluble) from cotton fabric into and through human skin. The percutaneous absorption of glyphosate from water solution was 1.42 ± 0.25% dose. This decreased to 0.74 ± 0.26% for glyphosate added to cotton sheets and immediately put onto skin. If the cotton sheets were dried for 1 or 2 days, then applied to skin, absorption was 0.08 ± 0.02% and 0.08 ± 0.01% respectively. However, wetting the 2-day dried cotton sheet with water to simulate sweating or wet conditions increased absorption to 0.36 ± 0.07%. Similar results were found for malathion. Absorption of malathion from aqueous ethanol solution was 8.77 ± 1.43%. This decreased to 3.92 + 0.49%, 0.62 ± 0.11% and 0.60 ± 0.14% for 0, 1- and 2-day-treated cotton sheets. However, malathion absorption from 2-day treated/dried cotton sheets increased to 7.34 ± 0.61% when wetted with aqueous ethanol. These results show that chemicals in fabric (clothing, rug, upholstery, etc.) can transfer from fabric into and through human skin to cause toxic effects.