Objective: To apply mass spectrometry-based techniques for the determination of background levels of metabolites of widespread organic solvents, such as styrene, in unexposed subjects from the general population.
Methods: The study population consisted of 129 healthy Italian subjects, not occupationally exposed to styrene (67 men; 37% smokers). Urinary levels of mandelic acid (MA) and phenylglyoxylic acid (PGA) were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS).
Results: Using LC-MS/MS, we were able to detect the peaks of MA and PGA in 100% of samples. The distribution of styrene metabolites was log-normal, the geometric means of MA and PGA concentrations being 0.443 mg/g creatinine [geometric standard deviation (GSD) 2.34] and 0.107 mg/g creatinine (GSD 3.49), respectively. The reference intervals estimated for MA and PGA were 0.084-2.339 and 0.009-1.238 mg/g creatinine, respectively.
Conclusion: The application of highly sensitive and selective mass spectrometry-based analytical techniques could be useful in the definition of reference values for metabolites of organic pollutants and for better assessment of low-level occupational exposure to organic solvents.