Cigarette smoke exposure and oxidative stress in Junior High School Children

Cigarette consumption annually increases. The number of smokers worldwide has reached 1.2 billion; 800 million are from developing countries. While smokers are at risk for smoking-related diseases, non-smokers exposed to smoking are also at risk. Cigarette smoke may lead to oxidative stress via active or passive exposure. The malondialdehyde (MDA) level in spot urine samples is a relevant biomarker representing oxidative stress. This study aimed to analyze urinary MDA levels in junior high school students in relation to cigarette smoke exposure. The population included all grade VIII students. Urinary MDA levels were evaluated using spectrophotometric measurement of thiobarbituric acid reactive substances in urine normalized to creatinine level, and fine particulate matter was measured. Other variables including smoking status (active or passive) and supplement consumption were assessed via questionnaires. The mean urinary MDA level of grade VIII was 32.26 μmol/g creatinine with a variation of 21.99 μmol/g creatinine. There was no significant difference in urinary MDA levels among students with active smoke exposure (active smokers). Likewise, there was no significant difference in urine MDA levels among students with passive smoke exposure (passive smokers). However, students who consumed supplements had significantly lower MDA levels than those who did not. Future studies are needed to explore other oxidative stress biomarkers that might play important roles in exposure to cigarette. Moreover, other biomarkers are needed to assess cigarette smoke exposure and antioxidant consumptions.