Urinary benzyl alcohol and hippuric acid in workers exposed to benzyl alcohol during paint stripping work

Objective: This research aimed to develop a reliable gas chromatography-mass spectrometry (GC-MS) method for detecting urinary benzyl alcohol (BeOH) concentrations and assess its suitability as a biomarker for occupational BeOH exposure.

Methods: Thirteen male participants exposed to BeOH during paint stripping work provided preshift and postshift urine samples, and their personal exposure concentrations were measured. Meanwhile, a control group of 10 nonexposed workers contributed urine samples. The newly developed GC-MS method met regulatory guidelines.

Results: The personal exposure concentrations of BeOH ranged from 8.4 to 45.2 mg/m3. Postshift urine samples from exposed participants showed significant BeOH and hippuric acid (HA) concentration increases compared to preshift samples (BeOH, post-/pre-shift geometric mean (GM) ratio = 7.5-7.8, p < 0.001; HA, post-/pre-shift GM ratio = 4.3-4.5, p < 0.001). These levels were considerably higher than those in postshift samples from the nonexposed control group (BeOH, exposed-/nonexposed-workers GM ratio = 14.8-19.0, p < 0.001; HA, exposed-/nonexposed-workers GM ratio = 12.1-15.3, p < 0.001), even after urine density correction.

Conclusions: Urinary BeOH and HA can serve as potential biomarkers of occupational exposure to BeOH. More specifically, BeOH might serve as a superior biomarker than HA because it is apparently less influenced by confounding factors such as dietary intake and genetic polymorphism of low-Km aldehyde dehydrogenase (ALDH2). The findings will improve workplace safety measures and protocols, assisting healthcare professionals in diagnosing and managing exposure-related health issues, thereby potentially reducing the risk of occupational exposure to BeOH.