Effects of Fish Oil in Alleviating Health Hazards Associated With Ozone Exposure

The investigators will conduct a randomized controlled trial among 64 healthy young adults in Shanghai, China. The eligible participants will be randomly assigned in a 2*2 factorial design to 1 of 4 groups: 1) fish oil and ozone exposure, 2) fish oil and shame exposure, 3) soy oil and ozone exposure, or 4) soy oil and shame exposure. The participants who take fish oil would receive 2.2 g/day (two 1.1-g capsules daily) in divided doses, and other participants will take the same amount of soy oil capsules. Two hour ozone exposure (200 ppb ozone) or shame exposure (0 ppb ozone) will be conducted in a chamber after four weeks of supplementation. Ozone is generated by a silent electric discharge method (HTU-500, AZCO Industries Ltd., Canada) and introduced into the chamber. The temperature and relative humidity in the chamber are maintained at 22±1℃ and 50%±5%, respectively. During the 2-hour exposure, each subject alternate 15 minutes of exercise on a treadmill and 15 minutes of rest. The exercise workload would be adjusted to achieve the targeted ventilation of 20±1 L/min/m2 body surface area. Health examinations will be conducted immediately prior to exposure, immediately after exposure, 2 hours after exposure and again the next morning.