Biomonitoring and evaluation of permethrin uptake in forestry workers using permethrin-treated tick-proof pants

Abstract

We conducted a randomized case-control trial to analyze uptake of the insecticide/arcaricide permethrin in wearers of permethrin-impregnated and non-impregnated pants in German forestry. Eighty-two male workers were each equipped for a 16-week period with permethrin-treated (test group) or with non-treated work pants (control group). Pants with or without lining to protect against cuts, obtained from two different distributors, were worn in each group. Urinary permethrin metabolite levels were measured by GC-MS/MS before, during and after wearing of the pants. Permethrin uptake was calculated using additional questionnaire data. In the control group, metabolite levels in the range of environmental background exposure (median: ~0.5 μg/l) were measured. Subjects wearing impregnated pants showed consistently significantly higher exposure levels even before the first use of the pants with a maximum after 1 week of wearing the pants (median: ~12.5 μg/l). Significant differences in internal exposure were found depending on which of the distributors the pants came from. Metabolite levels decreased probably due to permethrin losses associated with laundering the pants. Calculated permethrin uptake is below the value corresponding to the WHO-proposed acceptable daily intake. Based on our data, a marginally increased cancer risk compared with the general population cannot be excluded when wearing impregnated pants over a working-lifetime period.

Percutaneous absorption of chemicals from fabric (textile)

“…Of note, permethrin metabolites were still present 4 weeks after the study concluded (Table 2). Rossbach, Kegel, Süß, and Letzel (2016) showed similar findings of increased permethrin uptake from permethrin-impregnated work pants in forestry workers, with highest levels of permethrin urinary metabolites found 1 week into the 16-week study period. It was suggested that washing the pants throughout the study may have resulted in decreased permethrin concentrated within the pants, resulting in decreased percutaneous penetration.…”

Dermal uptake of phthalates from clothing: Comparison of model to human participant results

“…Strong nonequilibrium uptake has been observed for polybrominated diphenylethers to cotton and polyester, nicotine and ethylpyridine on cotton and nylon, and chlorpyrifos on plush toys . Body uptake has been observed due to wearing clothing that has been treated with pesticides and flame retardants …”

Effect of Environmental Temperature and Humidity on Permethrin Biomarkers of Exposure in U.S. Soldiers Wearing Permethrin-Treated Uniforms

“…Biomonitoring studies have shown that individuals wearing permethrin-treated clothing have significantly higher concentrations of urinary permethrin metabolites than those wearing untreated or conventional clothing, suggesting dermal exposure to the active ingredient as a result of wearing treated clothing. [12][13][14] Among German and U.S. Army soldiers, the duration of wear was associated with permethrin biomarkers measured in urine. 8,12,14,15 In addition to the length of wear time, environmental temperature, physical workload, and perspiration have been associated with increased permethrin absorption in forestry workers and U.S. Army soldiers wearing permethrin-treated clothing and uniforms, respectively.…”

“…[12][13][14] Among German and U.S. Army soldiers, the duration of wear was associated with permethrin biomarkers measured in urine. 8,12,14,15 In addition to the length of wear time, environmental temperature, physical workload, and perspiration have been associated with increased permethrin absorption in forestry workers and U.S. Army soldiers wearing permethrin-treated clothing and uniforms, respectively. [16][17][18] These results correspond to a body of literature that indicates absorption of chemicals following dermal exposure is affected by environmental conditions.…”