Dermal Absorption of Solvents as a Major Source of Exposure Among Shipyard Spray Painters

Objective: The purpose of this study was to evaluate the relevance of inhalational and dermal exposure to solvents in shipyard spray painters. Special emphasis was placed on the spatial distribution of dermal exposure and absorption across different regions of the body. Methods: Fifteen male spray painters were recruited for this study. The subjects were monitored during a 3-day work period using a repeated-measures study design. Air and dermal exposure of solvents were collected each day. Urine was collected before and after the work shift. Results: Air samples showed that the workers were primarily exposed to ethylbenzene and xylene. The concentrations of ethylbenzene and xylene outside the workers' masks were 59.2 ± 10.4 (mean ± standard error [SE]) ppm and 29.4 ± 4.70 ppm, whereas those inside the masks were 7.91 ± 77.4 ppm and 3.83 ± 8.22 ppm, respectively. The average mass of ethylbenzene and xylene across the different body regions inside the block units of assembled ships were 305.1 ± 63.9 mg and 165.6 ± 34.1 mg. The quantity was, on average, 5.8 and 5.1 times higher than those collected outside the blocks. In both measurements, the highest exposure mass was found on the upper legs, and the lowest exposure mass was found on the back. Principal component analysis (PCA) was used to transform the variables of dermal exposure for all investigated body regions into only one principal component. Multiple regression analyses revealed a significant relationship between dermal exposure to xylene (PCA dermal xyl) and urinary methylhippuric acid (MHA) levels, adjusting for air xylene exposure (R² = 0.491, P < 0.05). Conclusions: The present study indicated that dermal exposure to xylene significantly increased the urinary levels of MHA, suggesting that dermal exposure to solvents was an important route among spray painters.