Hair concentrations of nicotine and cotinine in women and their newborn infants.

BACKGROUND: To date, no biological markers have been identified that can predict the extent of fetal exposure to the toxic constituents of cigarette smoke. A variety of xenobiotic agents have been shown to accumulate in growing hair. PATIENTS AND METHODS: We measured maternal and neonatal hair concentrations of nicotine and cotinine in 94 mother-infant pairs. Mothers who were active smokers, nonsmokers, and passive smokers and their infants were included. RESULTS: Mothers who were active smokers (n = 36) had mean (SEM) hair concentrations of 19.2 (4.9) ng/mg for nicotine and 6.3 (4.0) ng/mg for cotinine, significantly higher than concentrations in nonsmokers (n = 35) (1.2 [0.4] ng/mg for nicotine and 0.3 [0.06] ng/mg for cotinine, P < .0001). Infants of smokers had mean hair concentrations of 2.4 (0.9) ng/mg for nicotine (range, 0 to 27.3 ng/mg) and 2.8 (0.8) ng/mg for cotinine (range, 0 to 12.2 ng/mg), significantly higher than concentrations in infants of nonsmokers (0.4 [0.09] ng/mg for nicotine and 0.26 [0.04] ng/mg for cotinine, P < .01). Mothers with passive smoke exposure and their infants (n = 23) had significantly higher hair concentrations of nicotine (3.2 [0.8] ng/mg for mothers and 0.28 [0.05] ng/mg for infants) and cotinine (0.9 [0.3] ng/mg for mothers and 0.6 [0.15] ng/mg for infants) than nonsmoking mothers and their infants (P < .01). There was a significant correlation between maternal and neonatal hair concentrations of nicotine (r = .49, P < .001) or cotinine (r = .85, P = .0001). CONCLUSIONS: This is the first biochemical evidence that infants of passive smokers are at risk of measurable exposure to cigarette smoke. Hair accumulation of cigarette smoke constituents reflects long-term systemic exposure to these toxins and therefore may be well correlated with perinatal risks.

Biological markers of intrauterine exposure to cocaine and cigarette smoking.

We describe hair tests for assessment of fetal exposure to cocaine and cigarette smoking. Cocaine and its major metabolites are incorporated into hair during the growth of the shaft and stay there for the whole life of the hair. Cocaine crosses the placenta and its metabolite benzoylecgonine, has been found in neonatal urine, meconium and hair. In order to utilize hair measurements of cocaine as a biological marker of systemic exposure, we conducted both animal and human investigations on the dose response characteristics of this phenomenon. Our data suggest that both maternal and fetal accumulation of cocaine and its metabolite follow a linear pattern within the regularly used doses. Similarly, a good correlation was observed in animals between maternal dose and fetal hair accumulation. To date, no biological markers have been identified that can predict the extent of fetal exposure to the adverse effects of toxic constituents of cigarette smoke. We measured maternal and fetal hair concentrations of nicotine and cotinine in mother-infant pairs. Smoking mothers had a mean of 21.3 +/- 18 ng/mg hair nicotine and 6 +/- 9.2 ng/mg of cotinine, significantly more than nonsmokers (0.9 +/- 0.8 ng/mg nicotine and 0.3 +/- 0.5 ng/mg cotinine, p < 0.0001). Babies of smokers had a mean nicotine concentration of 6 +/- 9.2 ng/mg (range 0-27.3) and cotinine of 2.1 +/- 3.7 ng/mg (range 0-12.2), significantly more than babies of nonsmokers (nicotine 0.6 +/- 0.7 ng/mg and cotinine 0.2 +/- 0.5 ng/mg; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)