Work related respiratory symptom prevalence and across shift lung function changes, and their relationships with endotoxin exposure were investigated in a potato processing facility in The Netherlands. The study population consisted of 61 male shift workers from the facility. Of the 68 personal endotoxin measurements taken, 90% were below 56 endotoxin units/cubic meter (EU/m3). Technicians and workers dealing with unloading/washing/grinding showed the highest exposure levels, and the largest variations in exposure. Workers from drying departments showed an intermediate mean exposure. Fourteen of the 57 workers (25%) reported at least one of four work related respiratory symptoms, predominately obstructive symptoms. These seemed to be more prevalent in the low endotoxin exposure category. Across shift lung function changes were associated with the level of endotoxin exposure. Personal exposure measurements revealed relatively low endotoxin concentrations. The increase in peak flow across the study period, being pronounced in workers with low endotoxin exposures, was probably due to a learning effect. Forced expiratory volume in 1 second and mid expiratory flow were significantly lower at the start of the work shift on the second day than at the start of the work shift on the first day. Apparently a complete recovery of the large lung function decrease during the first work shift was not achieved. Lung function decrease was roughly two fold larger across the first work shift after a 3 day absence from work, compared to the second and third shifts. The authors conclude that across shift lung function decreases in potato processing workers are related to endotoxin exposure levels about 53EU/m3. Endotoxin related effects appear to be larger in nonsmokers and larger on the first day after a period of absence from work.

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