Background

Printing industry use various chemical substances that can affect to worker’s health. Toxic substances such as dies containing benzene and toluene are used in finishing process. Trans,trans-Muconic acid (tt-MA) is an end product in the metabolism of benzene and is used as a biomarker for occupational monitoring of benzene exposure. Meanwhile, the hippuric acids are the principal metabolites of toluene. This study was aimed to assess subjective symptoms and the concentrations of urinary (tt-MA) and hippuric acid in printing workers in Medan city, Indonesia.

Materials and methods

This study was observational descriptive design conducted during Juny to July 2018. A total of 16 workers in 6 industries in Medan were selected for this study.  From each worker, urine sample was collected at the end of a shift and analysed for tt-MA and hippuric acids by high performance liquid chromatograph. Workers’ demographic characteristics and subjective symptoms were collected via questionnaires completed by the workers.

Results

The most frequently symptoms reported by workers were dizzines (68.8%), followed by exhausted and headache (56.3%), and difficult to concentrate (43.8%). The range concentrations of tt-MA and hippuric acids obtained were 35.36 to 909.72 µg/g creatinine (Cr) ppm and 3.39 to 555.31 mg/g Cr, respectively. There were 2 workers (12.5%) exceed the maximum level of 500µg/g Cr for urinary ttMA level.

Conclusions

The results showed that subjective symptoms had affected more than half workers, and the  benzene exposore has contributed to increase urinary tt-MA.

Acknowledgements

This research was supported financially by  Directorate of Research and Community Service, General Directorate of Strengthening Research and Development of Research, Technology and Higher Education Ministries in Accordance with the Funding Agreement of Research and Community Service for Fiscal Year 2018