Dosage indicators in farm workers exposed to mancozeb

A study was performed on a group of farm workers exposed to mancozeb to validate dose indicators. Two indirect methods have been employed to monitor the air-dispersed mancozeb in the working environment (average concentration 57.2 micrograms/Nm3): carbon disulfide and manganese dosage. The latter proved to be more applicable. To assess skin contamination, the concentration of mancozeb was measured on pads placed on work overalls and in the liquid employed to wash workers' hands. Average concentrations of 0.86 microgram/cm2 and 641 micrograms respectively were obtained. A good correlation between mancozeb concentration on pads and in the air was found. Urinary ethylenethiourea (ETU) and manganese measured before and after a three day exposure were selected as indicators for internal dose. In all cases except three (2.9-2.3 and 4.4 mg/g creat.) ETU was below the sensitivity limit of the method employed. Urinary manganese increased from a mean of 0.32 microgram/g creat. to a mean of 0.53 microgram/g creat. after the exposure. The correlation with environmental data was r = 0.667.