Epidemiological studies have shown that exposure to tobacco smoke causing irritation and inflammation in the airways tends to reduce serum periostin concentrations in adults. We now investigate prospective cross-sectional study on 135 Korean students aged 7 years in the first grade who were participating in the Seongnam Atopy Project for Children's Happiness 2016 (SAP2016) cohort. To the best of our knowledge, this is the first study to show significant inverse correlations between serum periostin concentration and exposure to xylene and formaldehyde in children. Our findings suggested the need for caution in using the serum periostin level as a marker for allergic diseases, since exposure to volatile organic compounds and formaldehyde may confound the interpretation of these results.