[Study of passive smoking measured by urinary cotinine in maternal and child protective health centers in North-Pas-de-Calais].

BACKGROUND The aim of the study was to determine the circumstances of exposure to environmental tobacco smoke, to evaluate its importance by measurement of urinary cotinine, and to study the relationship with the children's medical history. POPULATION AND METHODS It was a prospective investigation realized in 20 outpatient pediatric clinics. The parents answered a questionnaire to assess the child's exposure as well as the child's medical and surgical history. Cotinine was measured in urine samples collected during the visit. Concentrations > 6 ng/mL were considered to be positive. RESULTS Two hundred and one children were included in the study (mean age 17 months, extremes: 1-72 months), 107 of whom were exposed to environmental tobacco smoke. Urinary cotinine was found to be positive in 27 cases (13%). There was a positive relation between passive tobacco exposure and positive urinary cotinine (P < 0.001). Eighty of 201 mothers and 135 of 185 fathers smoked. There was a relation between positive urinary cotinine and the mother's smoking, as well as with a history of upper respiratory tract infection (rhinitis, otitis media) or adenoidectomy. No relation was found between a history of bronchiolitis and passive smoking. CONCLUSIONS Passive tobacco exposure is very frequently encountered in our region. Urinary cotinine, which can be easily measured, might constitute an efficient tool in order to convince the parents of the reality of passive smoking.