Table 1.
Urine levels of metabolites of hazardous compounds in e-cigarette-only users versus dual users and non-smokers
| Hazardous compounds | E-Cigarette–only users | Dual users | Non-smoker controls | |||
|---|---|---|---|---|---|---|
| Median | Range | Median | Range | Median | Range | |
| PMA (ng/mg of creatinine; benzene) | 0 | 0–2.0 | 0.2** | 0–2.4 | 0 | 0–0.1 |
| HEMA (ng/mg of creatinine; ethylene oxide) | 0.5 | 0–7.6 | 1.0* | 0–8.2 | 1.3 | 0–4.0 |
| CNEMA (ng/mg of creatinine; acrylonitrile) | 1.3 | 0–108.4 | 59.4** | 3.7–142.6 | 0** | 0–1.6 |
| 3-HPMA (ng/mg of creatinine; acrolein) | 254.3 | 0–2311.6 | 439.7* | 153.6–814.4 | 192.8* | 0–1416.4 |
| 2-HPMA (ng/mg of creatinine; propylene oxide) | 28.8 | 0–1382.6 | 40.2 | 10.2–310.9 | 15.2** | 0–34.5 |
| AAMA (ng/mg of creatinine; acrylamide) | 67.3 | 0–581.2 | 235.6** | 41.4–574.7 | 34.5** | 0–182.0 |
| HMPMA (ng/mg of creatinine; crotonaldehyde) | 148.7 | 0–793.4 | 185.4 | 110.0–437.9 | 100.4* | 0–522.1 |
The concentrations of metabolites were normalised to creatinine values. PMA phenylmercapturic acid (metabolite of benzene), HEMA 2-hydroxyethylmercapturic acid (metabolite of ethylene oxide), CNEMA 2 cyanoethylmercapturic acid (metabolite of acrylonitrile), 3-HPMA 3 hydroxypropylmercapturic acid (metabolite of acrolein), 2-HPMA 2-hydroxypropylmercapturic acid (metabolite of propylene oxide), AAMA 2-carbamoylethylmercapturic acid (metabolite of acrylamide), HMPMA 3-hydroxy-1-methylpropylmercapturic acid (metabolite of crotonaldehyde)
*P < 0.05 or **P < 0.01 versus e-cigarette–only users’ group. Data adapted from Rubinstein et al. [9]