The effect of essential oil on heart rate and blood pressure among solus por aqua workers

Background: Aromatherapy is widely used around the world for stress relief. Whether exposure to essential oilincreases the risk of cardiovascular events is still unknown. The purpose of this study was to investigate the effect ofessential oil on heart rate and blood pressure among solus por aqua (spa) workers.Methods: We recruited 100 healthy workers from various spa centres in Taipei, Taiwan. Between July and August of2010, three repeated measurements - resting heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure(DBP) - were taken of each spa worker in our study room. Participants were exposed to essential oil vapourgenerated from an ultrasonic atomizer in the study room for two consecutive hours. The total volatile organic compound(VOC) level in the study room was measured during the study period. We used a linear mixed-effect model todetermine the association between the total VOC level and the participants HR, SBP, and DBP.Results: For the times from 15 to 60 min after start of exposure, we found that the VOC level was significantlyassociated with reduced 15-min mean BP and HR. After exposure for more than 1 hour, from 75 to 120 min afterstart of exposure, we found that the VOC levels were associated with increased 15-min mean BP and HR.Conclusions: Exposure to essential oil for 1 hour was found to be an effective method of relaxation, as indicated bydecreases in the HR and BP. Prolonged exposure for longer than 1 hour to essential oils may be harmful to cardiovascularhealth among spa workers.