Measuring inhalant abuse among homeless youth in southern Brazil.

In order to measure urinary level of hippuric acid among Brazilian homeless youth suspected of having inhaled toluene in previous hours, urine samples were voluntarily collected from the youth around two hours after they arrived at an "open-school" in Porto Alegre, Brazil. Hippuric acid levels were determined by gas chromatography in urine specimens of 50 homeless children and adolescents. In 86% of the urine specimens, hippuric acid levels were within the range of 3.6 g/g creatinine and 46.1 g/g creatinine. Very high urinary hippuric acid level may indicate voluntary toluene abuse. A cut-off urinary hippuric acid level value needs to be established for toluene self-exposure diagnosis.