Reducing Traffic Pollution Exposure Improves Blood Pressure

Air Pollution Clinical Trial

Official title:

Near Highway Pollution: From Research to Action

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04029129
• Other study ID #: 19X-183=1
• Secondary ID: R01ES026980
• Status: Completed
• Phase: N/A
• Start date: March 1, 2018
• Est. completion date: June 15, 2018

Study information

• Verified date: September 2023
• Source: UConn Health
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This randomized trial assessed the effect of modifying building envelop and level of air filtration on blood pressure over two hour exposure sessions.

Description:

Living close to major roadways is associated with elevated blood pressure (BP) amongst other adverse health effects. There is growing evidence that ultrafine particles (UFP, <100 nm in diameter), which are elevated near major roads and highways, contribute to such risks. We assessed the efficacy of high efficiency particulate arrestance (HEPA) filtration and building envelope adjustment at reducing exposure to and health effects of air pollution next to major highways.

We used a randomized three-period crossover trial design to assign 77 participants (aged 40-75 and without diagnosis of hypertension) to three two-hour exposure sessions. Sessions were conducted in one of two rooms immediately adjacent to highways. High, medium and low exposures were attained by varying the degree of air exchange and amount of HEPA filtration in the room. During high exposure sessions, the room was ventilated with outdoor air and no filtration was used. During low exposure sessions, leakage of outdoor air into the room was minimized and HEPA filtration was maximized. During medium exposure sessions, a moderate amount of HEPA filtration was used (less than half of that used in low sessions). Indoor particle number and black carbon (BC) concentrations (i.e., markers of traffic-related air pollution) were monitored continuously.

During each session participants sat quietly and wore noise-cancelling headphones, while their BP was monitored every ten minutes using an ambulatory BP monitor. We monitored pulse and oxygen saturation continuously.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 77
• Est. completion date: June 15, 2018
• Est. primary completion date: June 15, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 40 Years to 75 Years

Eligibility

Inclusion Criteria:

• The inclusion criterion was age 40-75 years.

• There was a preference for people who were otherwise healthy, but overweight or obese.

Exclusion Criteria:

• A history of a major cardiovascular outcome (including myocardial ischemia (MI), stroke, angina)

• Other serious health problems (current asthma or COPD)

• Taking anti-hypertensive medications

• Smoking or living with a smoker

• Cognitive impairment

• Working at a job with high combustion exposure (taxi/truck driver, restaurant cook)

• High combustion exposure in the preceding 24 hours (driving on the highway, cooking in a restaurant, driving a truck)

• Not speaking English or Chinese.

Related Conditions & MeSH terms

• Air Pollution

Intervention

Other:
• Air filtration and building envelop modifications
Air filters and closing and sealing of windows and doors was used to reduce infiltration of air pollution from outdoors in rooms next to major highways at rush hour.

Locations

Country	Name	City	State
United States	University of Connecticut	Farmington	Connecticut

Sponsors (2)

Lead Sponsor	Collaborator
UConn Health	National Institute of Environmental Health Sciences (NIEHS)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Systolic Blood Pressure (SBP)	Systolic blood pressure measured with ambulatory blood pressure monitors in mmHg.	Over 2 hour exposure period, we measured SBP after 20 minutes with the objective to assess change in SBP in a time series of measurements over that time period.
Secondary	Diastolic Blood Pressure (DBP)	The unit of measurement, mmHg for the diastolic blood pressure.	Over a 2 hour exposure period with the objective to assess change in DBP measured after 10 minutes in a time series of measurements over that time period.