Passive cigarette smoke exposure in primary school children in Liverpool

OBJECTIVE

To assess environmental tobacco smoke (ETS) exposure amongst primary school children.

METHODS

A descriptive, community-based, cross-sectional study of self-reported parental smoking patterns and children's salivary cotinine concentrations in 245 children aged 5-11 years attending 10 primary schools in Liverpool.

RESULTS

The mean age was 7.4 years. The percentage of children living in smoking households was higher than the average reported for England (61.4% vs 53.0%). The average daily number of cigarettes smoked was similar for fathers (15.8) and mothers (16.4). The mean salivary cotinine concentration (+/-SD) was 1.6+/-0.4 ng/ml, and was higher in boys than girls (1.9+/-0.4 vs 1.2+/-0.2 ng/ml, P=0.006). The mean cotinine concentration was higher amongst children less than 7 years of age compared with older children (1.9+/-0.9 vs 1.4+/-0.6 ng/ml, P=0.01). Children from disadvantaged socio-economic households (Townsend score > + 6) had a mean cotinine level of 1.9+/-0.4 ng/ml, and a higher risk of a positive cotinine-validated level (>or=1 ng/ml) [crude odds ratio (OR) 3.5, 95% confidence interval (CI) 1.6-5.2). Maternal, but not paternal, cigarette smoke exposure was significantly associated with the salivary cotinine-validated level in children (adjusted OR 2.5, 95%CI 1.8-3.4).

CONCLUSIONS

Maternal smoking, age less than 7 years, child's gender (male) and low socio-economic status were significant risk factors associated with ETS exposure in young school children in Liverpool. The level of childhood ETS exposure in this area demonstrates a major public health concern that creates a challenge for innovative interactive strategies.

Measurement of nicotine and cotinine in human milk by high-performance liquid chromatography with ultraviolet absorbance detection

A high-performance liquid chromatographic (HPLC) assay for the determination of nicotine and cotinine in human milk was developed using an extraction by liquid-liquid partition combined with back extraction into acid, and followed by reverse-phase chromatography with UV detection of analytes. The assay was linear up to 500 microg/l for both nicotine and cotinine. Intra- and inter-day relative standard deviations (R.S.D.) were <10% (25-500 microg/l) for both nicotine and cotinine. Limits of quantitation (LOQ) were 10 and 12 microg/l for nicotine and cotinine, respectively, while the limits of detection (LOD) were 8 and 10 microg/l for nicotine and cotinine, respectively. The mean recoveries were 79-93% (range 25-500 microg/l) for nicotine and 78-89% (range 25-500 microg/l) for cotinine. The amount of fat in the milk did not affect the recovery. We found that this method was sensitive and reliable in measuring nicotine and cotinine concentrations in milk from a nursing mother who participated in a trial of the nicotine patch for smoking cessation.