Personal exposure samples were collected and analyzedfrom two groups of agricultural field workers in the San JoaquinValley of California. The first group was involved in citrus har-vest in Tulare County. The second group was involved in tablegrape operations in Kern County. Airborne dust exposures weremeasured for a total of 5 working days for each crop over thepeak labor months of June through September 1992. Samplingdates were approximately 1 month apart, except in September,when 2 consecutive days were monitored for each crop. Taskswere selected to be representative of those performed by laborcrews throughout the summer months. For citrus, harvestingwas the task measured for all five sampling visits. For tablegrapes, the task on the first sampling visit was leaf pulling;harvesting table grapes was conducted for the remaining foursampling visits. For both crops, 14 workers were monitoredduring each visit. Ten workers were fitted with respirable dustsamplers to measure respirable dust and respirable quartz expo-sures. Four workers were fitted with inhalable dust samplers tomeasure inhalable dust, endotoxin, and total bacteria and fungiexposures.