Pesticides in the cultivation of carnations in greenhouses: Part II--Relationship between foliar residues and exposures.

The relationship between the levels of dermal and respiratory exposure to pesticides and the amount of pesticide on the leaves of the plants has been studied during cutting of carnations in greenhouses. The study was focused on four pesticides and performed in 18 farms in the Netherlands. Dermal exposure measured by using long-sleeved cotton gloves is strongly related to the amount of dislodgeable foliar residue (DFR). A transfer factor from leaves to hands of approximately 4500 cm2/hr (one-sided projected area) has been calculated. Small differences have been noticed between the different pesticides. Dermal exposure of hands and forearms to pesticides during cutting of carnations can be predicted from measurements of DFR. The DFR was mainly determined by the amount of pesticide remaining from previous applications and the last application rate, not by the application technique (spraying or dusting). The concentrations in the breathing zone after dusting of zineb (dustable powder) and chlorothalonil (wettable powder) were significantly correlated with the dislodgeable foliar residue. The concentrations of thiram did not correlate with DFR. Respiratory exposure results from dispersion of foliar dust containing pesticides.