Methanol reference values in urine from inhabitants of Brazil

In order to properly evaluate the results of the occupational biomonitoring of chemicals it is necessary to establish reference values for the biomarkers of exposure. The aim of this study was to determine the reference values for methanol in urine of the general population non-occupationally exposed to the xenobiotic under study. Thus, urinary methanol was measured in 84 occupationally non-exposed subjects from the city of São Paulo, Brazil, by means of headspace gas chromatography with a flame ionization detector. The results revealed a mean of 2.26 +/- 1.26 mg methanol/l urine and a geometric mean of 2.10 mg/l for the studied population. The reference values varied within the range of 0.50-4.78 mg/l (mean +/- 2 S.D.). Methanol levels in urine did not differ statistically between male and female subjects. Urinary methanol in the total population was less than 4.80 mg/l in 95% of cases.