Changes in Oxidative Stress Status in New House Environment

Abstract

P-314 Introduction: Sick building syndrome is widely recognized socially as a disease but has not been defined as a clinical symptom. The causal factors of sick building syndrome are originated from various environmental conditions. In this study, we evaluated the DNA damage and malondialdehyde (MDA) levels for genotoxicity and cytotoxicity in volunteers in new house environment compared with control subjects. Methods: Formaldehyde concentration levels were measured by HPLC. We also investigated 25 healthy persons who have lived the same apartment for the over 5 years as control subjects and 28 volunteers who moved into new apartment to evaluate the oxidative stress, including genotoxicity and cytotoxicity. In addition, we assessed the correlation between the indoor concentration of formaldehyde and the DNA damage and urinary MDA levels. Results: The formaldehyde level was 170 ppb in the new apartments, which was about 2.1 times higher than that specified in Japan Environmental Guideline (80 ppb). In a comet assay, the mean values of Olive tail moments were 2.10±0.14 and 1.55±0.17 (p<0.05) in the volunteer and control groups, respectively. The volunteer group showed a significantly higher increase in DNA damage in lymphocytes compared to the control group. The urinary MDA levels were 3.69 ± 3.27 and 1.34 ± 0.68 μmol/g creatinine (p<0.05) in the volunteer and control groups, respectively. There was a statistically significant correlation between the urinary MDA levels and the indoor concentration of formaldehyde (r=0.846, p<0.05); there was not in the control group. Conclusions: The increases in the DNA damage in lymphocytes and urinary MDA levels were significantly higher in the volunteer group than in the control group. It was also found that the correlation between the urinary MDA levels and the indoor concentration of formaldehyde was significantly high. In this study, we found evidence of genotoxicity in the volunteer group with increased oxidative stress, and formaldehyde may be a causal agent for the increased oxidative stress in the volunteer group.