Benzene Monitoring and S-Phenylmercapturic Acid Determination of Workers at Oil Sites in Congo-Brazzaville


Ebenguela Ebatetou Ataboho*, Josue Richard Ntsimba Nsemi and Donatien Moukassa

The toxicity of benzene is well known, and its leukemia effect established. It is a natural constituent of crude oil and the diseases associated with its exposure are recognized as occupational.

Objective: To assess occupational exposure to benzene among workers in an oil and gas production company.

Materials and methods: This was a descriptive, cross-sectional study which consisted first of the quantification of atmospheric benzene by individual measurements in a sample of the homogeneous exposure group of the producers. Secondly, urinary assays of S-phenylmercapturic acid were performed at the end of the shift in the selected workers.

Results: The study included 79 (47.88%) workers, 17 atmospheric samples were usable and 79 urinary assays at the end of the shift were performed. The average benzene concentration for all sites was 10 times lower than the regulatory average exposure value (1 ppm=3.2 mg/m3): average: 0.122 pp, median: 0.053 ppm and range: 0.019-1.448 ppm. All 79 urinary assays of S-phenylmercapturic acid with a biological exposure index of less than 25 μg/g creatinine: mean: 0.70 μg/g creatinine creates, median: 0.52 μg/g creatinine creates and extends: 0.23 to 6.7 μg/g creatinine.

Conclusion: Exposure was below the limit values for benzene in both atmospheric metrology and biometrology. This is an occupational group with low exposure to benzene. Medical surveillance will therefore have to be adapted according to the potentially exposing tasks.