Influence of sebum and stratum corneum hydration on pesticide/herbicide collection efficiencies of the human hand.

Abstract

The adhesion of house dust particles and chemical residues to the hands after contact with a variety of surfaces can yield significant exposures to children. Chemicals present on the surface or absorbed into house dust particles may adhere to the hands and subsequently are available for ingestion or absorption through the skin under normal physiological conditions. Contact of a hand with a surface occurs primarily through a thin layer of sebum and sweat on the skin surface. The study presented here examined the effect of the composition of the sebum and sweat layer on the adhesion of a mixture of pesticides and a herbicide to a hand after contact with a house-dust-laden surface. Collection efficiencies on the hand for atrazine and malathion were correlated with sebum levels on the palm of an individual hand. The increase in sebum values measured in this study caused a 13 percent and 8 percent reduction in collection efficiency, respectively, for atrazine and malathion applied to house-dust-laden surfaces. Diazinon and chlorpyrifos collection efficiencies were correlated with skin hydration levels measured on the palm of the individual's hand. The increased skin hydration measured in this study caused a 7 percent and 5 percent reduction in collection efficiency, respectively, for diazinon and chlorpyrifos.