Table 2.
Mean, P95 values, and distribution of workers by the levels of hippuric acid and methylhippuric acid in gasoline station workers (occupationally exposed to VOCs) and office workers (comparison group) from Rio de Janeiro (Brazil), 2015–2017.
| Variables | Office workers1 (n = 100) | Gasoline station workers2 (n = 275) | p value | |
|---|---|---|---|---|
| Convenience store workers (n = 94) | Filling station attendants (n = 181) | |||
| Toluene (hippuric acid (HA)) | ||||
| Mean ± SD | 0.083 ± 0.19 | 0.393 ± 0.308 | 0.319 ± 0.271 | 0.001∗ |
| P95 | 0.609 | 1.087 | 0.869 | |
| Reference: mean of OW–n (%)3 | ||||
| ≤0.083 | 79 (79.0) | 7 (7.4) | 25 (13.8) | <0.001# |
| >0.083 | 21 (21.0) | 87 (92.6) | 156 (86.2) | |
| Xylene (methylhippuric acid (MHA)) | ||||
| Mean ± SD | 0.016 ± 0.051 | 1.714 ± 1.333 | 1.456 ± 1.266 | 0.001∗ |
| P95 | 0.110 | 4.977 | 3.996 | |
| Reference: means of OW–n (%) | ||||
| ≤0.016 | 85 (85.0) | 1 (1.1) | 2 (1.1) | <0.001# |
| >0.016 | 15 (15.0) | 93 (98.9) | 179 (98.9) | |
1Not occupationally exposed to toluene and xylene. 2Occupationally exposed to toluene and xylene. 3Mean (g/g creatinine) of the office worker group was used as a cutoff point. ∗Kruskal–Wallis test. #Chi-square test.