[Significance of fluoride monitoring in the aluminum industry].

Fluoride emission determination was introduced in the aluminium industry some years ago in order to detect subjects suspected of having fluorosis. Fluoride exposure has been reduced by means of successive improvements in working conditions in aluminium reduction plants to such an extent that today industrial fluorosis can be said to be an occupational disease of the past. Generally values of up to 7 mg F/l urine (USA) or per g of creatinine (FRG) at the end of a working period apply today as guaranteed to prevent fluorosis developing at the workplace. The values observed today at Alusuisse plants are below 5 mg/l. Ten years ago mean values of up to 6.2 mg/l were found. It is nevertheless expedient to continue with a regular determination of fluoride emission, however for a different purpose than before. The determination of the urine output directly at the end of a working period (postshift measurement) shows the exposure during this short period. Once the relative contents of different pollutants in the air compared to the fluoride air values are known, the exposure of the subject examined to other pollutants can be estimated on basis of the fluoride values in the urine. Differences between individuals can also be recorded. It has been found that even at identical workplaces there are individuals time and time again who have considerably higher values than their co-workers.(ABSTRACT TRUNCATED AT 250 WORDS)