Assessment of Occupational Exposure to Malathion and Bifenthrin in Mosquito Control Sprayers Through Dermal Contact
Pornpimol Kongtip PhD*, Somnuek Sasrisuk MS*, Smart Preklang MS**, Witaya Yoosook PhD*, Dusit Sujirarat MS***
Affiliation : * Department of Occupational Health and Safety, Faculty of Public Health, Mahidol University, Bangkok, Thailand ** Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand *** Department of Biostatistics, Faculty of Public Health, Mahidol University, Bangkok, Thailand
Objective : To assess occupational exposure of malathion and bifenthrin concentrations by dermal contact and urinary 3-(2-
chloro-3, 3, 3-trifluoro-1-propenyl)-2, 2-dimethyl-cyclopropanecarboxylic (TFP) acid, health symptoms developed and the
relationship between bifenthrin concentrations and TFP acid in urine of the mosquito control sprayers.
Material and Method: The aerosols of these two pesticides were collected using 100 cm2 cotton patches attached on the skin
of upper legs of 54 volunteer of mosquito control sprayers. Their urine samples were also collected before and after
application.
Results : These subjects exposed to average malathion and bifenthrin concentrations of 0.18 and 0.32 μg/cm2, respectively.
After application, the average concentration of urinary TFP acid in the sprayers was 39.22+50.77 mg/g creatinine ranging
from 0.58 to 261.19 mg/g creatinine. A significant difference was found between urinary TFP acid levels before and after
application (p<0.001) but the bifenthrin concentrations through dermal contact and urinary TFP acid levels were not
significantly correlated (p>0.05).
Conclusion : The mosquito control sprayers had dermal contact with smoke of malathion and bifenthrin and some sprayers
developed health symptoms after exposure. They should use protective clothing made of plastic, nylon or polyester to protect
sprayers from skin contact.
Keywords : Malathion, Bifenthrin, TFP acid, Mosquito control sprayers
