Table 1.

Characteristics of the study population and the distribution of reported smoking and toenail biomarker

n (median)5-95 percentile range
Age (y)2,485 (56.0)42-62
Physical activity (h/wk)2,027 (2.0)1-4
Alcohol intake* (g/d)2,217 (1.8)0.0-32.8
Body mass index2,375 (23.9)19.4-34.3
Toenail nicotine for all participants (ng/mg)2,485 (0.21)0.06-4.06
Toenail nicotine for never smokers with no SHS exposure (ng/mg)157 (0.10)0.05-0.41
Toenail nicotine for never smokers with SHS exposure (ng/mg)768 (0.14)0.05-0.83
Toenail nicotine for current smokers (ng/mg)771 (1.77)0.24-6.34
n% of Population
Never smokers988/2,48540
Past smokers726/2,48529
Current smokers771/2,48531
SHS among never smokers768/2,31433
Occasionally70
Frequently30
Toenails infected with fungus568/2,48523
Nail polish used122/2,4854.9
  • * Using 1980 questionnaire 2 y before the toenail collection.