This is a randomized controlled human exposure crossover study. Investigators aim to investigate the acute health effects of ozone exposure in healthy young adults.
The investigators will conduct a randomized controlled human exposure crossover study among 32 healthy young adults in Shanghai, China. Each subject will be exposed twice: once to clean air and once to 200 ppb ozone in a chamber for 2 hours. During the 2-hour exposure, each subject will be requested to alternate 20 minutes of rest and 10 minutes of exercise on a treadmill. The exercise workload will be adjusted to achieve the targeted ventilation of 25 \~ 27 L/min(approximately equal to 15 \~ 18L/min/m2 body surface area). Ozone will be 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 will be maintained at 22±1℃ and 55%±5%, respectively. Health examinations will be conducted immediately prior to exposure, immediately after exposure, 2 hours after exposure and again the next morning. Health examinations include symptom questionnaire, skin tests, spirometry, and Holter monitoring. We plan to collect blood, buccal, urine, nasal secretion, saliva, exhaled breath condensate, sebum, and D-squame samples.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Enrollment
32
The exposure group will be exposed to 200 ppb ozone in a chamber for 2 hours while alternating 20-min rest and 10-min exercise periods. The exercise workload will be adjusted to achieve the targeted ventilation of 25 \~ 27 L/min(approximately equal to 15 \~ 18L/min/m2 body surface area). The temperature and relative humidity in the chamber will be maintained at 22±1℃ and 55%±5%, respectively.
The control group will be exposed to 0 ppb ozone in a chamber for 2 hours while alternating 20-min rest and 10-min exercise periods. The exercise workload will be adjusted to achieve the targeted ventilation of 25 \~ 27 L/min(approximately equal to 15 \~ 18L/min/m2 body surface area). The temperature and relative humidity in the chamber will be maintained at 22±1℃ and 55%±5%, respectively.
Department of Environmental Health, School of Public Health, Fudan University
Shanghai, China
Changes of FEV1
Changes of forced expiratory volume in 1 second
Time frame: FEV1 will be examined immediately prior to exposure, immediately after exposure, 2 hours after exposure and again the next morning
Changes of FVC
Changes of forced vital capacity
Time frame: FVC will be examined immediately prior to exposure, immediately after exposure, 2 hours after exposure and again the next morning
HRV
Heart rate variability
Time frame: Holter monitoring will be performed continuously for 24 hours.
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