This study aims to assess the effects of acute exposure to traffic-related air pollution and the underlying mechanisms.
The investigators will conduct a randomized, crossover trial among 72 healthy young adults in Shanghai, China. The eligible participants will be randomly divided into 2 groups (36 volunteers per group). During the first stage, participants will be requested to take one walking task (from 13:00 to 17:30). The exposed group will walk along a busy road and be exposed to traffic-related air pollution, while the control group will walk in a traffic-free park. During the first 3 hours, all participants will rest for 30 minutes after each 15-minute walking. From 16:00, participants will stop walking and rest for 1.5 hours. Then both groups will enter a 2-week washout period. In the second stage, there will also be one walking task (from 13:00 to 17:30). The two groups will exchange their walking sites and repeat the previous trial. Physical examinations will be performed both before and after each walking task. Besides, we will ask volunteers to stay in school during the two days before walking. Health examinations include symptoms questionnaires, blood pressure tests, Holter monitoring, and spirometry. We plan to collect blood, urine, oropharyngeal swabs, and exhaled breath condensate before exposure, about one hour after exposure, and next morning.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
SINGLE
Enrollment
69
The intervention group will walk along a busy road and be exposed to traffic-related air pollution for 4.5 hours (from 13:00 to 17:30), while alternating 15-minute walking and 30-minute rest periods.
The control group will walk in a traffic-free park for 4.5 hours (from 13:00 to 17:30), while alternating 15-minute walking and 30-minute rest periods.
Department of Environmental Health, School of Public Health, Fudan University
Shanghai, Shanghai Municipality, China
Changes in FEV1
We plan to measure changes in forced expiratory volume in 1 second.
Time frame: FEV1 will be examined before exposure, half an hour after exposure and 12 hours after exposure.
Blood Pressure
We plan to measure systolic blood pressure (SBP) and diastolic blood pressure (DBP).
Time frame: Blood pressure will be measured for 24 hours from 8:00 am on the morning of intervention to 8:00 am on the next morning.
Heart Rate Variability Parameters
We plan to measure heart rate variability (HRV) parameters.
Time frame: Volunteers will be asked to wear electrographic Holter monitors for 24 hours from 8:00 am on the morning of intervention to 8:00 am on the next morning.
Changes of FVC
Changes of forced vital capacity
Time frame: 7:00 AM on the day of the walking session, half an hour after exposure and 12 hours after exposure (next morning)
Changes of FEV1/FVC
Changes of the ratio of forced expired volume in 1 second (FEV1) to forced vital capacity (FVC)
Time frame: 7:00 AM on the day of the walking session, half an hour after exposure and 12 hours after exposure (next morning)
Changes of MMEF
Changes of maximal mid-expiratory flow
Time frame: 7:00 AM on the day of the walking session, half an hour after exposure and 12 hours after exposure (next morning)
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