Determination of the Relation Between Passive Cigarette Smoking in Children and Respiratory Tract Infections by Evaluation of Urine Cotinine/Creatinine Levels

Aim: Passive smoking is an important public health issue due to the clinical problems it causes. In this study, we determined the effect of passive smoking on respiratory tract infections using a survey method, family history, and urine cotinine/creatinine ratio. Methods: Seventy-two children who came to the Pediatric Outpatient Clinic at Istanbul Bagcilar Training and Research Hospital for a check-up with no current health problems between November 2020 and March 2021 were included in this prospective cross-sectional study. The study group included 36 children with at least one active smoker in the house, and the control group included 36 children with no active smokers in the house. With the survey, sociodemographic variables about the family and child as well as the frequency of lower or upper respiratory tract infection history were questioned. Cotinine and creatinine levels were measured using the urine samples of the patients included in the study. Results: The frequency of respiratory tract infections in the last two years was increased in the group with an active smoker in the household. The frequency of bronchopneumonia in the case group was 44.4%, whereas it was 5.6% in the control group. The sinus infection was seen in 22.2% of those in the case group, while there were no sinus infections reported in the control group. Bronchopneumonia and sinus infections were statistically significant in the case group (p<0.01 and p<0.01 respectively). The median cotinine levels in the active smokers in the house group were 20.94 ng/mL (0-491) and 16.62 ng/mL (0-121) in the nonsmoker group. 55.6% of children with a history of cigarette smoke exposure and a urine cotinine level higher than 10 ng/mL were considered passive smokers (the normal range is 0-10 ng/mL). Conclusion: Frequent respiratory tract infections and hospitalization may be prevented by informing families about the risks of exposure to cigarette smoke as well as raising awareness of the harms of cigarette smoke.

Automated summary

This study found that passive smoking in households increases the frequency of respiratory tract infections in children. It is important to raise awareness about the harmful effects of passive smoking on children's health both at home and in society.