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Revista de Saúde Pública

On-line version ISSN 1518-8787


PAULA, Flávia Cristina S de; SILVEIRA, Josiane Nicácio; JUNQUEIRA, Roberto Gonçalves  and  LEITE, Edna Maria Alvarez. Assessment of urinary trans, trans-muconic acid as a biomarker of exposure to benzene. Rev. Saúde Pública [online]. 2003, vol.37, n.6, pp. 780-785. ISSN 1518-8787.

OBJECTIVE: To assess the use of trans, trans-muconic acid as a biomarker of occupational exposure to benzene. METHODS: Trans, trans-muconic acid in urine samples of exposed (exposed group, n=36) and non-exposed (non-exposed group, n=116) workers to benzene. Urinary levels of trans, trans-muconic acid were quantified by high-performance liquid chromatography. The study sample consisted of subjects exposed to benzene in an oil refinery in Belo Horizonte, Brazil. Non-parametric statistical analysis was carried out using Kruskall-Wallis test, Mann-Whitney test and Spearman correlation at p<0.05. RESULTS: Workers were exposed on average to benzene levels of 0.15±0.05 mg/m3 (0.05 ppm) and they showed a urinary trans, trans-muconic acid mean value of 0.19±0.04 mg/g of creatinine. The reference value range of trans, trans-muconic acid in non-exposed subjects was 0.03 to 0.26 mg/g of creatinine (mean 0.10±0.08 mg/g de creatinine). There was seen a statistical difference between trans, trans-muconic acid levels in urine samples from exposed and non-exposed groups. There was no correlation between urinary trans, trans-muconic acid and air benzene levels. There was no correlation between urinary trans, trans-muconic acid levels in the exposed group and smoking. Alcohol consumption up to 48 hours before sampling procedure showed no effect on trans, trans -muconic acid levels in both exposed and non-exposed groups. There was however a correlation between age (range 18 to 25 years) and urinary metabolite levels in the latter group. CONCLUSIONS: The results show that it is important to evaluate the effect of age and smoking habits on urinary trans, trans-muconic acid levels.

Keywords : Benzene [analysis]; Occupational exposure; Biological markers; Trans, trans-muconic acid.

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