Effects of Short-Term Forest Bathing on Human Health in a Broad-Leaved Evergreen Forest in Zhejiang Province, China

Objective To investigate the effects of short-term forest bathing on human health.Methods Twenty healthy male university students participated as subjects and were randomly divided into two groups of 10.One group was sent on a two-night trip to a broad-leaved evergreen forest,and the other was sent to a city area.Serum cytokine levels reflecting inflammatory and stress response,indicators reflecting oxidative stress,the distribution of leukocyte subsets,and plasma endothelin-1 (ET-1) concentrations were measured before and after the experiment to evaluate the positive health effects of forest environments.A profile of mood states (POMS) evaluation was used to assess changes in mood states.Results No significant differences in the baseline values of the indicators were observed between the two groups before the experiment.Subjects exposed to the forest environment showed reduced oxidative stress and pro-inflammatory level,as evidenced by decreased malondialdehyde,interleukin-6,and tumor necrosis factor α levels compared with the urban group.Serum cortisol levels were also lower than in the urban group.Notably,the concentration of plasma ET-1 was much lower in subjects exposed to the forest environment.The POMS evaluation showed that after exposure to the forest environment,subjects had lower scores in the negative subscales,and the score for vigor was increased.Conclusion Forest bathing is beneficial to human health,perhaps through preventive effects related to several pathological factors.

• No significant differences in the baseline values of the indicators were observed between the two groups before the experiment. Subjects exposed to the forest environment showed reduced oxidative stress and pro‐inflammatory level, as evidenced by decreased malondialdehyde, interleukin‐6, and tumor necrosis factor α levels compared with the urban group. Serum cortisol levels were also lower than in the urban group. Notably, the concentration of plasma ET‐1 was much lower in subjects exposed to the forest environment. The POMS evaluation showed that after exposure to the forest environment, subjects had lower scores in the negative subscales [decrease in negative mood], and the score for vigor was increased.
o In the present study, the concentration of negative air ions was also determined, and a significantly higher daytime level of negative air ions was recorded in the forest environment (1509.1±357.0 cm‐3) than in the urban area (263.3±99.3 cm‐3). Thus, our finding about the Biomed Environ Sci, 2012; 25(3): 317‐324 323 beneficial effect of forests for humans may be at least partly due to the abundance of negative air ions.