Table 2.

Levels of total NNAL, total cotinine, and total nicotine in the urine of 144 infants exposed to ETS

% (n)Mean ± SDRange
All samples
Total NNAL (pmol/mL)100 (144)0.083 ± 0.200ND*-2.12
Total cotinine (nmol/mL)100 (144)0.133 ± 0.190ND-1.81
Total nicotine (nmol/mL)100 (144)0.069 ± 0.102ND-1.02
Samples with detectable biomarkers
Total NNAL (pmol/mL)46.5 (67)0.179 ± 0.2640.029-2.12
Total cotinine (nmol/mL)93.1 (134)0.143 ± 0.1940.006-1.81
Total nicotine (nmol/mL)97.9 (141)0.070 ± 0.1030.006-1.02
  • Abbreviation: ND, not detected (below the limit of quantitation).

  • * Detection limits were calculated for each sample and were as follows: total NNAL (0.09-0.36 pmol/mL), total cotinine (0.5-2 ng/mL), and total nicotine (0.5-2 ng/mL). A value of zero was used for samples which were below the limit of detection. To convert nmol cotinine to ng, multiply by 176; for nicotine, multiply by 162.