Fig. 5.

Correlation between passive smoking and urinary nicotine metabolite concentrations in non-smokers. Results show total concentrations (free + glucuronide); *p < 0.01, ^†p < 0.001, significant difference compared with groups with lowest values by t-test with logarithm. a Smoking at workplace: prohibited (open bars, n = 6), partially prohibited (gray bars, n = 88), permitted (black bars, n = 23). b Smokers at home (black bars, n = 39), no smokers at home (open bars, n = 70). Answers to the questions about smoking conditions at home and in the workplace were not obtained from 8 participants