Aims: The purpose of the study was to evaluate the significance and practicability of the questionnaire Q18 and the psychological-neurological questionnaire PNF to detect styreneassociated symptoms during medical surveillance at the workplace. Material and Methods: The study population consisted of 75 employees exposed to styrene from eight factories. The physical examinations were performed according to the guidelines “Berufsgenossenschaftlichen Grundsatz für arbeitsmedizinische Vorsorgeuntersuchungen G 45 (Styrol)”. The questionnaires Q18 and PNF were used and the styrene exposures were determined. Participation was voluntary. Results: The mean styrene value in air was 14 ppm (max.: 84 ppm). The MAK value (“maximale Arbeitsplatz-Konzentration”: maximum workplace concentration) of 20 ppm was exceeded in 30 % of the samples. The sum of the styrene metabolites mandelic acid and phenylglyoxylic acid (MA+PGA) was 345 mg/g creatinine on average. The BAT value (“Biologischer Arbeitsstoff-Toleranz-Wert”: biological tolerance value for occupational exposures) was exceeded in 23% of cases. The values for styrene in air and MA plus PGA in urine correlated significantly. On average, the styrene-exposed workers reported more health complaints than the control persons in both questionnaires. Exposed employees with German as their native language were found to have abnormal test results twice as frequently as the control persons. However, the differences are not significant. There was no significant correlation between the parameters of exposure and the scores in the questionnaires. In contrast, there are consistently significant relationships between the dimensions of the positive and negative affectivity and the complaint scores. The results of the Q18 and PNF correlate significantly with one another. It takes about two minutes to answer the Q18. This is about half as long as for the complete PNF questionnaire. The comprehensibility of both questionnaires is similar. Conclusions: The following procedure is recommended for using questionnaires Q18 and PNF in medical examinations by company physicians:
I. The use of standardized questionnaires can only be recommended as a screening method for German-speaking workers.
II. For the interpretation of abnormal results, the individual internal styrene exposure must be determined. Common and usual non-work related causes for the complaints should be considered.
III. Workers with abnormal test results and increased styrene exposure should be examined with a comprehensive neuropsychological test system (neurotoxic evaluation system, ANES).
IV. If the results are outside the normal range, additional neurological and follow-up investigations are recommended.